400E 400E jerking/hesitation/power loss between 4000-6000 rpm

[lightdude95]

Hello everyone, my name is Sam, a 25yo engineering student from Belgium. I just bought a 151 000 km (or about 100 000 mile) euro w124 400e from 1992 and I absolutely love it. It is packed with all thinkable options (including ASR) and drives/shifts like a dream. I have one problem though for which I haven't found a solution yet despite searching and trying all kind of fixes.

Basically, the car starts and runs fine (starts after about 2 seconds of cranking), but between 4000 and 6000 rpm there is a very aggressive jerking which really throws me out of my seat. This doesn't happen all the time, lets say about 80% of the time when I rev it to that rpm range. This happens in all gears, with or without kickdown. Also, there is a very noticable 'light' power loss at about 4250 rpm, even with WOT, it's like you back off of the gas a bit. This happens regardless of wether the car does the jerking thing or not. Besides all that, the engine also shake a bit too much in idle in my opinion.

The following things have been done to the car by myself in the past two months:

- Engine oil, oil filter and air filters
- tranny oil and filter change (including oil in torque converter)
- installed new bushings on shift rod (old ones were non existant)
- checked working of NSS: car does not start in any other gear except P or N, so NSS is doing it's job?
- new fuel filter (old one was from 1995 lol) (all filters from MANN)
- oil pan was dented, replaced with new one and changed the oil pump pickup with the newer, wider model as well)
- replaced oil level sensor too while bottom end was open
- fuel pump relay replaced (green one)
- new plugs (f8dc4), coils, leads, caps and rotors (all bosch with beru leads)
- new intake air temp sensor
- maf has been taken out and cleaned with maf cleaner (car still does the jerking, even with maf disconnected too, rubber grommet between eta and maf was in good condition)
- all vacuum connections in engine bay have been replaced
- ETA cleaned and tested, works fine, very responsive
- wiring looms (upper, lower and eta) been checked: all original, but all insulation looks like new and is very flexible, no deterioration whatsoever
- all fuses replaced with new ones (including the four 10A ones on the GM module)
- exhaust disconnected right infront of cats and driven, still does the jerking so cats are not clogged
- capacitors inside LH-module checked, none have leaked
- ezl reacts to vacuum, engine also fires on all 8 pots so I think ezl is fine too
- fuel pressure checked, I remember it should be 3.6 or 3.5 bars, mine jumped straight to 4 bars upon fuel pumps turning on
- liqui moly injector cleaner added to fuel, made engine run much better
- ASR disabled by jumping the pins on the diagnostic socket (I think pin 4 and ground), still does the jerking (very fun to drive though haha)
- rev limiter kicks in at around +-5250 rpm in P and N, same as my friends 400E, a 500E I have driven and a 500SEL, so I think that's working like it should

As you can see I have done a number of things which were suggested on this board and on the entire internet in general. I would also like to add that the ASR light never lights up. It just starts jerking like mad and when I back off the throttle it shifts up and acts normal. The point at which it jerks is not fixed, it happens between 4000 and 6000 rpm. Like I said, sometimes it doesn't jerk at all, yet I always feel a subtle power loss at about 4250rpm.

I still plan on changing the camshaft magnets, the insulator cups behind the rotors and also the pins of the diagnostic socket hence those can corrode and short out. It would be surprising if any of that helps, but I already have the parts so why not. Personally I lean more towards bad fuel pumps, causing pressure drops in the system, because after all, I tested the fuel pressure at idle without driving the car. Fuel pumps are quite expensive though (100 euro's a piece), and hence I'm still a student, I don't want to invest in those if they don't end up being the culprit...

It's getting kinda frustrating because every time I think i have found the solution, it turns out to be a dead end. That's why I wanted to ask you guys for help, hoping to find a solution together so that I could enjoy this amazing car for the remainder of the summer before it gets cold and rainy again.

Thanks in advance!
Sam

 

[195910]

Hi Sam, where in Belgium are you located? might be able to point you to the right direction.

 

[gsxr]

You've ruled out an awful lot of items. I had a car with similar symptoms, related to load, not necessarily RPM. Under high load, it would jerk/buck wickedly. Fuel pressure was normal at idle, but under load, fuel pressure dropped dramatically. Using a fuel pressure gauge visible while driving pinpointed the fault. Replaced the pumps and the problem was cured. I don't know if that's what's going on with your car though. However if the fuel pumps are original from 1992, it is good preventive maintenance to replace them with new OEM Bosch. They aren't cheap, but they WILL eventually fail...



Oh, and welcome to the forum!

 

[gsxr]

Also:

1) If you have not yet checked fault codes, you MUST do that... clear all codes, go drive the car so it jerks and hesitates, then check codes again. If there are no codes on any of the 5 powertrain modules, that may indicate an issue with fuel delivery or ignition system. There are no sensors in the fuel system and therefore no codes for fuel delivery issues; and intermittent ignition faults don't trigger codes.

2) I just realized you did NOT replace the insulators behind the distributor rotor. At least remove the rotor bracket and inspect the back of the insulator for fluid! This is free... but this problem generally causes misfiring at lower RPM's, not a high-RPM hesitation.

3) Cam advance magnets would not cause your issue, but if leaking oil (common problem), it would be nice to fix them.

4) Engine shake at idle is very likely failed engine mounts. Measure the air gap from oil pan to crossmember. Make sure you are sitting down when looking at the price for new OE mounts. Unfortunately all the aftermarket mounts are Chinese now, can't get OEM Boge anymore.

 

[lightdude95]

Hi guys, thanks for the fast replies! Very happy to find people who are ready to help me out!

I am located near Kortrijk.

I still have to read codes indeed, but haven't had time yet with my exams and so on. Same with the insulators, will check them soon though.

Indeed: I forgot to mention that it only happens during load and not when I rev it in P or N, which is why I lean towards a fuel problem instead of an ignition problem.

About the mounts: I wanted to replace the engine and tranny mounts in the beginning of april, then I saw the prices (I insisted on installing OEM because, as you said, all aftermarkets are very low quality nowadays). Was +500 euro's in parts, so thats something for later on.

I'll see where I can find the best deal on the bosch pumps and install them. After reading the codes first of course. Is there a code involving fuel pressure on these cars?

Kind regards
Sam

 

[gsxr]

I'll see where I can find the best deal on the bosch pumps and install them. After reading the codes first of course. Is there a code involving fuel pressure on these cars?

Nope. There are no sensors in the fuel system, so the computers don't know what the rail pressure is. So there cannot be a code stored for fuel pressure out of spec.

 

[lightdude95]

Nope. There are no sensors in the fuel system, so the computers don't know what the rail pressure is. So there cannot be a code stored for fuel pressure out of spec.

Oh ok thanks for the info. I'll do the things you suggested in the coming weeks. I will keep you guys up to date. Thanks again!

Sam

 

[lightdude95]

Hi guys

Wanted to let you know that I changed both fuel pumps today and sadly the car is still acting up. Very frustrating to say the least. I guess next up is a code readout, will have to make an appointment for that.

In the meantime: against all odds, would it be worthwhile to swap ezl's? I have a friend with a 400e so I could check. Even though most ezl's fail half way or completely, it could be possible this is one type of failure too right?

Kind regards
Sam

 

[gsxr]

It's almost certainly NOT the EZL.

You don't need an appointment to read codes. You can buy or build a hand-held blink code reader to read & clear most all faults. You only need to visit the dealer/mechanic if you want live data from a digital scanner (or, buy a Chinese SDS C3 and do it yourself).

Really need to get fault codes to help at this point.

 

[lightdude95]

I looked up the blink code reader schematic, looks quite easy to make. Will give it a go. This weekend. As always, I'll keep you guys up to date.

 

[Kridre]

I think it would be worth replacing overload protection switch in transmision. I had almost identical problem at around 4000rpm up to 6000rpm car would bog and hesitate but only sometimes. Problem with this switch should be stored in fault codes.

 

[lightdude95]

Hi guys,

Some "good" news at last: I made the blink code reader and read all codes and cleared them, went for a drive and made the car do its thing again and headed back home to read the codes.

All pins were clear (1 blink), except pin 17. It gave me the following codes: 6 (camshaft sensor failure) and 8 ( Transmission overload protection switch (S65) does not close).

So it appears @Kridre's suggestion about the tranny overload protection switch was aimed in the right direction indeed! So I guess I should order a new switch and o-ring? Will ATF spill out when changing this switch?

I also 'tested' the camshaft position sensor by pulling out the cable. Engine took much longer to start than usual. When I plugged it back in it started right up in 1 second (I timed it). So why is the ecu giving me a code about it?

Sam

 

[Kridre]

There would be some ATF spil when changing the switch not too much to worry about. After removing this switch there is also a part that is actually pushing brake band in transmission. When replacing this switch i suggests to also replace parts 301, 299 and 300. You can buy two different overload switches at the dealer go whatever is cheaper I don't know if there is any difference between them.

P/N
301 - 140-277-01-51 Spacer ring
299 - 005-997-80-48 O-ring
300 - 016-997-34-48 O-ring
304 - 016-997-35-48 O-ring at the end of Overload Switch
Switch 002-545-45-14 or 003-545-25-14 Go with cheaper option.

 

[gsxr]

If you keep getting the cam sensor code, replace the sensor. It's not that expensive. Could be it has an intermittent fault when hot, or something like that. If you have access to a spare used one, try that first - they are pretty rare failures. I'm assuming the engine harness is good, btw - a bad harness could cause problems since it plugs into this sensor. The cam sensor may be related to your 4250rpm glitch, as the cam advance solenoids are supposed to de-energize around that RPM.

The OL switch is a much more common failure, but what I usually find is that it causes a delayed WOT upshift at redline, without affecting engine power. But it's possible there are different failure modes with different symptoms. Definitely replace the OL switch and see what happens.

 

[lightdude95]

The CMP sensor from MB is over 150 euro's, online I found several brands (Febi, EPS Facet, KW) for around 30-40 euro's. I think they will do the job just as good, right?

For removal of the OL switch; after removing the connector and the switch itself, how do I remove the valve and the seals that @Kridre suggested to replace as well? Do I just pull them out or do I need some sort of magnet? I'm also wondering wether I'll even be able to get the valve out, since there is very little space between the transmission and the tunnel walls.

 

[Kridre]

You can just pull it out. I think I used small pliers put some rubber at the end of them, pushed them inside of valve hole and puled it out. There will be enough space to do it on the car.
Like this:

 

[lightdude95]

You can just pull it out. I think I used small pliers put some rubber at the end of them, pushed them inside of valve hole and puled it out. There will be enough space to do it on the car.
Like this:
View attachment 109879
View attachment 109878

Alright perfect, thanks! I called MB today and ordered all the parts. Gonna do this together with the camsensor next week.

Will keep you up to date

 

[Jlaa]

- wiring looms (upper, lower and eta) been checked: all original, but all insulation looks like new and is very flexible, no deterioration whatsoever

hi @lightdude95, this may not specifically related to your hesitation issue, but if you have the original ecojunk wiring harnesses, it is almost certain that wires INSIDE the insulation are in a really poor state....
even if the outside insulation looks ok. I replaced the upper and lower looms on my own car at around 6x,xxx miles. Everything looked ok on the outside, but when I cut open the outside insulation, I was shocked at the deteriorated state of the inside wires. I have some pictures on my owner thread.

For what it is worth, replacing the lower harness solved an oil pressure gauge reading issue, and replacing the upper harness solved an issue that was related to AC compressor not always switching on / auxiliary electric fans operating in an unpredictable manner.

 

[lightdude95]

hi @lightdude95, this may not specifically related to your hesitation issue, but if you have the original ecojunk wiring harnesses, it is almost certain that wires INSIDE the insulation are in a really poor state....
even if the outside insulation looks ok. I replaced the upper and lower looms on my own car at around 6x,xxx miles. Everything looked ok on the outside, but when I cut open the outside insulation, I was shocked at the deteriorated state of the inside wires. I have some pictures on my owner thread.

For what it is worth, replacing the lower harness solved an oil pressure gauge reading issue, and replacing the upper harness solved an issue that was related to AC compressor not always switching on / auxiliary electric fans operating in an unpredictable manner.

Hello @Jlaa

Thanks for your suggestion. I am planning on replacing the wiring harnesses eventually to have some peace of mind for the coming years (just graduated now and they're quite expensive ), but I actually did cut open the outer insulation to check the inner leads. They all looked good on all harnesses. I did this in several locations, then closed everything back up with heat resistant electrical tape. But in the worst case scenario, if the tranny switch and cam sensor don't fix it, I'll probably have no choice and will start saving up to change the harnesses and see wether that eliminates this very frustrating issue.

Kind regards
Sam

 

[LWB250]

hi @lightdude95

For what it is worth, replacing the lower harness solved an oil pressure gauge reading issue, and replacing the upper harness solved an issue that was related to AC compressor not always switching on / auxiliary electric fans operating in an unpredictable manner.

Very common on M119 powered cars. The lower harness is often overlooked, but due to much of it being jacketed it stays stable for some years. The oil pressure is often a "tell" unless the sender is bad, which is also a common failure. As an aside, don't ever use anything but the correct OE or VDO sender. The others are junk.

Dan

 

[Etanox]

Hi Sam ,

Your problem can be the wiring of the cam sensors. Or the cam magnets could be snagged with oil . Last time i opened up an m119 i saw oil burned up around the solenoids ( thats what they called normally ? Lol? )
Cleaning them up solved the problem . Check the sensors pins . They usually are cracked or corrosion , junk . Whatever they call it. Because that engine had the same problem . The cam sensor after failure it sets itself to a emergency value programmed on ecu . So at higher rpm the value not changing could be the culprit of your problem.

Hope this helps you some , if any

Etanox

 

[lightdude95]

Hi Sam ,

Your problem can be the wiring of the cam sensors. Or the cam magnets could be snagged with oil . Last time i opened up an m119 i saw oil burned up around the solenoids ( thats what they called normally ? Lol? )
Cleaning them up solved the problem . Check the sensors pins . They usually are cracked or corrosion , junk . Whatever they call it. Because that engine had the same problem . The cam sensor after failure it sets itself to a emergency value programmed on ecu . So at higher rpm the value not changing could be the culprit of your problem.

Hope this helps you some , if any

Etanox

Thank you for your reply. There is oil on the cam magnet pins indeed, which I clean off every now and then. I am planning on replacing them as well (already have the new magnets and the special sealant). I'll keep you updated! Thanks again.

Sam

 

[gerryvz]

Thank you for your reply. There is oil on the cam magnet pins indeed, which I clean off every now and then. I am planning on replacing them as well (already have the new magnets and the special sealant). I'll keep you updated! Thanks again.

Sam

If you replace the cam solenoids, and the replacements start with the 119 part number (which are what is currently available new from MB), you MUST also order new armatures. The 119 part number solenoids have a different internal profile than the old/stock 104 part number solenoids, and require the updated armature to work properly. Fortunately the armatures are cheap to buy from MB.

I detailed this recently in my resto thread, in this post. You can see some comparisons between the old and new solenoids and armatures.

 

[lightdude95]

If you replace the cam solenoids, and the replacements start with the 119 part number (which are what is currently available new from MB), you MUST also order new armatures. The 119 part number solenoids have a different internal profile than the old/stock 104 part number solenoids, and require the updated armature to work properly. Fortunately the armatures are cheap to buy from MB.

I detailed this recently in my resto thread, in this post. You can see some comparisons between the old and new solenoids and armatures.

Hi Gerry,

Thank you for letting me know, didn't have a clue about the different armatures. I'm guessing I'll need new bolts and roll pins as well? So all in all two times 59, 62 and 65 in the attached picture I suppose. Is it possible to hold the armature while loosening the nut without removing the valve covers? May I also ask the torque spec of the armature bolt?

Thanks again for the heads up!

Sam

 

[gsxr]

Just 2 each solenoids, armatures, and bolts. The roll pin should be included as part of the new armature, IIRC.

 

[gerryvz]

I would not re-use the bolts. I ordered new ones -- they are cheap from MB. The roll pins, you shouldn't need them (I have a set that I didn't use). Basically for the armature replacement, you just need #59 and #65, both x2. Plus the solenoids too.

If you look at the photo I made of the old and new solenoids, you can see the internal profile on the newer solenoid has a much straighter/sharper edge, while the older one is more rounded. The armatures follow this -- the old armatures have a rounded profile, the newer ones are more squared off.

See the attached.

The torque for the armature bolt is ~7-8 Nm. Don't pay attention to the instructions that have the "second version" and angle torquing and all that. Just get two new armature bolts and torque them each to 7-8 Nm. IIRC I used a single drop of Blue Loctite on each one.

 

[lightdude95]

Alright great, thanks guys! One last question for @gerryvz: in your thread I saw that you held the armature with a wrench while undoing the bolt. Can that be done with the valve covers on the engine? In other words: just with the magnet removed without any further disassembly. If not; is it possible to loosen and tighten the bolt without holding the armature and just relying on the "engine friction"?

Btw I almost forgot: I changed the camshaft position sensor today and while not completely solving my issue, the slight power loss at 4250rpm is gone! The hesitation and jerking has also "moved up" to about +5500rpm. So I'm hoping the tranny OL switch will be the last piece of the puzzle. Will install that later this week. Cam magnets and relatables will be for end of this month or next month (starting my first 'real' job in two weeks ).

I already want to thank everyone who has helped me get this far!


Kind regards
Sam

 

[gerryvz]

There is no "engine friction" for the armature. It turns back and forth freely and there is no "drag" on it.

You MUST hold the armature with a wrench to loosen the bolt. Yes, I believe it's possible to do this without removing the valve cover. You can pull the armature outward about 1 cm to make extra room for the wrench to grab its' flat sides.

 

[lightdude95]

Hello everyone

Some updates: I changed the transmition OL switch + the plastic cap and o-rings of the B1 valve today. Hesitation and jerking is gone! Can't put in words how happy I am Thank you all for the help!!!!

BUT: one minor inconvenience though... At 5500rpm the car still loses some power, like as if I back off the throttle a bit. After doing the pull, for about a minute it's also a bit low on power in general, then it restores itself. I am also getting code 6 on pin 17 again (bad cmp).

So as far as I know, there's only one cmp on this engine right? Which I already changed. Could there be a distance issue with the shims between the sensor and the head, making the sensor not able to follow pulses at high rpm's? There were two shims when I changed the cmp, I put them both back in (no idea about the thicknesses btw). Or could this be an issue with the cam magnets? AFAIK the magnets energise between 2000-4000rpm so no idea how they would affect the 5500rpm region.

At this point I wish I could buy you all a drink for helping me get so far.

Kind regards
Sam

 

[gsxr]

More progress, that is good!

Yes, there is only one cam position sensor. Normally you would use the same shims. But it wouldn't hurt to check the air gap per FSM specs. And yes, this should not affect power at 5500rpm.

Just curious - can you post the part numbers of your EZL and LH module? And there are no fault codes on any other modules?

 

[195910]

Hello everyone

Some updates: I changed the transmition OL switch + the plastic cap and o-rings of the B1 valve today. Hesitation and jerking is gone! Can't put in words how happy I am Thank you all for the help!!!!

BUT: one minor inconvenience though... At 5500rpm the car still loses some power, like as if I back off the throttle a bit. After doing the pull, for about a minute it's also a bit low on power in general, then it restores itself. I am also getting code 6 on pin 17 again (bad cmp).

So as far as I know, there's only one cmp on this engine right? Which I already changed. Could there be a distance issue with the shims between the sensor and the head, making the sensor not able to follow pulses at high rpm's? There were two shims when I changed the cmp, I put them both back in (no idea about the thicknesses btw). Or could this be an issue with the cam magnets? AFAIK the magnets energise between 2000-4000rpm so no idea how they would affect the 5500rpm region.

At this point I wish I could buy you all a drink for helping me get so far.

Kind regards
Sam

Happy to hear its solved, thanks to @Kridre for his contribution.

 

[lightdude95]

More progress, that is good!

Yes, there is only one cam position sensor. Normally you would use the same shims. But it wouldn't hurt to check the air gap per FSM specs. And yes, this should not affect power at 5500rpm.

Just curious - can you post the part numbers of your EZL and LH module? And there are no fault codes on any other modules?

Hi Dave

See attached for ezl and lh-module part numbers.

As for codes, I got the following ones today:

pin 4: 17
pin 8: 5, 6, 7
pin 17: 6
pin 25: 15

Several new ones as you can see. Regarding pin 8: Today was very hot, and the A/C does only blow ice cold every now and then, so hopefully its the belt that is slipping which causes the compressor clutch to disengage. I recharged the gas last week (1kg of r134a) and have a new belt as well. Just waiting to install it until I have time to pull the alternator and change the bearings and voltage regulator at the same time. (really bad bearing noise coming from alternator).

 

[gsxr]

Thanks for the photos. The modules appear correct.

The main concern I see is you are still getting the cam sensor code, even with the new sensor. That might be related to your remaining high-RPM power issues. Most of the other stuff is nothing to worry about (assuming your AC works, etc). The CAN communication error on the LH module (with E-GAS) is odd, if it keeps recurring.

 

[lightdude95]

Thanks for the photos. The modules appear correct.

The main concern I see is you are still getting the cam sensor code, even with the new sensor. That might be related to your remaining high-RPM power issues. Most of the other stuff is nothing to worry about (assuming your AC works, etc). The CAN communication error on the LH module (with E-GAS) is odd, if it keeps recurring.

Hi Dave,

Thanks for your reply. I hope it has something to do with the shims on the camshaft sensor... I find it odd that there were 2 on top of each other. I'll try running it with one shim and see what happens. Will give the wiring another good look too.

About the CAN error: On the pdf i have it says that this code can occur without any error or malfunction being present. Oddly enough I couldn't erase it either, kept showing up. First time I saw this code btw. Car runs great though...

 

[lightdude95]

Hello everybody,

Quick update: I checked the wiring of the cam sensor again; every single wire has mint insulation, even bended it back and forth, very flexible and 'fresh' so to say.

Took the cam sensor out and measured the two shims. One is 0.4 mm thick and the other one 0.3 mm. By removing the 0.3 mm one, the head of the sensor contacts the tab on the camshaft which creates the pulses (I checked this with engine off of course), so both shims are certainly necessary to prevent the sensor from being hit.

Read codes again, where I found a very odd thing: code 17 from pin 4 was gone lol. Other codes were still there. On top of those, on pin 17 I found a new code: 28. That is another comms error with the e-gas module I believe.

Car still runs textbook perfect as long as I keep it under 5500rpm. Anything above that and it loses a bit of power, gets lazy at all rpm's before returning back to normal after a minute or 2.

The mystery continues...

Sam

 

[195910]

Hello everybody,

Quick update: I checked the wiring of the cam sensor again; every single wire has mint insulation, even bended it back and forth, very flexible and 'fresh' so to say.

Took the cam sensor out and measured the two shims. One is 0.4 mm thick and the other one 0.3 mm. By removing the 0.3 mm one, the head of the sensor contacts the tab on the camshaft which creates the pulses (I checked this with engine off of course), so both shims are certainly necessary to prevent the sensor from being hit.

Read codes again, where I found a very odd thing: code 17 from pin 4 was gone lol. Other codes were still there. On top of those, on pin 17 I found a new code: 28. That is another comms error with the e-gas module I believe.

Car still runs textbook perfect as long as I keep it under 5500rpm. Anything above that and it loses a bit of power, gets lazy at all rpm's before returning back to normal after a minute or 2.

The mystery continues...

Sam

You need to do the cam actuation test. The camshaft adjustment has 3 positions depending on RPM range: advance - retart - advance
If its switching between the positions then it shouldn't be the cam solenoids, it switches to advance again at around 4700RPM.

 

[lightdude95]

You need to do the cam actuation test. The camshaft adjustment has 3 positions depending on RPM range: advance - retart - advance
If its switching between the positions then it shouldn't be the cam solenoids, it switches to advance again at around 4700RPM.

Oh ok, I always thought it was retard - advance - retard, with the advance being from 2k to 4k rpm. How do I conduct this cam actuation test?

Cheers

 

[195910]

Oh ok, I always thought it was retard - advance - retard, with the advance being from 2k to 4k rpm. How do I conduct this cam actuation test?

Cheers

Sorry I need to confirm the sequence, but as you can see it not happening around 5500rpm but around 4000RPM. which makes it unlikely for the solenoids to be the culprit
Actuation test is done via star diagnose.
Have you checked the adaptation values? on/off ratio

 

[lightdude95]

Sorry I need to confirm the sequence, but as you can see it not happening around 5500rpm but around 4000RPM. which makes it unlikely for the solenoids to be the culprit
Actuation test is done via star diagnose.
Have you checked the adaptation values? on/off ratio

No I don't have the equipment for that, the dealer here could do it for me though.

 

[gsxr]

The actuation test just engages the solenoids at idle, and the idle should get rougher. You can manually do this by applying +12v to each solenoid at idle, but will have to clear the fault codes afterwards.

Page 22 here:

https://www.500eboard.co/misc/Manuals/Servicev3.2/W124/w124CD1/Program/Engine/LHIS/07.4-0030.pdf

 

[lightdude95]

The actuation test just engages the solenoids at idle, and the idle should get rougher. You can manually do this by applying +12v to each solenoid at idle, but will have to clear the fault codes afterwards.

Page 22 here:

https://www.500eboard.co/misc/Manuals/Servicev3.2/W124/w124CD1/Program/Engine/LHIS/07.4-0030.pdf

View attachment 111167

Hi Dave

Wow nice pdf, thanks! So just hook up 12V in idle (minding the correct polarity of course)? Can this be an external 12v source? Or anywhere in the engine bay where I can tap battery voltage?

To check wether the voltage feed to the magnets is in working order, can I disconnect the wires and measure them with a multimeter in park while revving the engine? (Hence in the pdf it says in P or N it will advance at 3k rpm)

 

[gsxr]

Any 12v source will work, you just need to make the solenoid energize. Disconnect the wires from the engine harness and apply voltage only to the solenoid terminals. This will produce a fault code because the LH module knows the harness is unplugged from the solenoid, so you will have to clear the fault afterwards.

There's no need to rev the engine. At idle, when either cam solenoid is engaged, idle becomes noticeably rough. This indicates the cam advance mechanism is working (and, also that the camshafts are timed correctly).

If you want to do live testing at higher RPM you need to drive the car with SDS connected, but I don't think this is your problem... if the solenoids are not working, midrange power is poor, but top-end power is normal.

 

[lightdude95]

Yeah that is pretty logical.

It's odd, I just went for a drive again, and really payed attention to the behaviour of the car. It goes like this: car pulls with lots of power, transition from retard to advance and back to retard goes very smooth and unnoticable. As soon as I make it go past ~5500rpm the power decrease kicks in, and stays.

Here's the weird part: after the decrease in power happens, if I smash the throttle again, at somewhere between 2k and 3k rpm the car regains it power. Weird to say but it's almost as if the cam mechanisms are "sticking" and become unstuck suddenly. Of course I'm just trying to say what I feel the car doing, no idea what the actual issue is.

Cam sensor error remains as well...

I'm starting to feel bad asking so many things to you guys, don't want to bother you all with my issues. If one of you ever ends up in Belgium, I'd love to buy you a beer or two.

Sam

 

[gsxr]

Although this may not help much, here's a video of what SHOULD be happening at full throttle:

 

[lightdude95]

Although this may not help much, here's a video of what SHOULD be happening at full throttle:

Yup, hits redline like a dream... mine revs up slower after 5500rpm but still reaches redline and upshifts fine.

 

[gsxr]

Any chance you could post a video of your tach during a WOT run into 3rd gear? I'm curious what it looks like.

You MIGHT consider disconnecting the exhaust crossover pipe again, to rule out catalysts causing issues at high RPM.

 

[lightdude95]

Any chance you could post a video of your tach during a WOT run into 3rd gear? I'm curious what it looks like.

You MIGHT consider disconnecting the exhaust crossover pipe again, to rule out catalysts causing issues at high RPM.

Of course, I'll try to do a run tomorrow.

Sure I can disconnect the x-pipe and test it once more, though I must add that it's a very sharp electronical feeling cutoff, and power restores itself as sharp again. So hopefully not a cat problem.

 

[gsxr]

Sure I can disconnect the x-pipe and test it once more, though I must add that it's a very sharp electronical feeling cutoff, and power restores itself as sharp again.

Ah, that is a good point... if it's a sharp cutoff with a delay before power returns, it's probably not catalysts.

 

[195910]

Shifting point adjustment?

 

[lightdude95]

Shifting point adjustment?

You mean the bowden cable right? I noticed the two 'arrows' are not lining up so I'll need to reajust that, already have the pdf with the procedure for asr models. There is a rod in the throttle mechanism that had a lot of play on it so I order a new one (circled in yellow on the pic attached).

Update: just got a call; MB can't deliver this part anymore.... (A0010706375)

On top of that, I ordered a new throttle cable as well, hence half the thread of the adjuster on the current one is broken so I couldn't remove the play on the system (see second pic attached).

Thanks for the headsup, it's all coming together...