M119 Ignition issues when warm

[jsmulhollandiv]

Hello all,

New member of eboard and new Owner of a 95 SL500 (35K miles only) with M119 engine.

A little bit of background: Recently took over a car from my father. He bought it new in 95 and drove it for about 17 years. Then, it was unfortunately left (read: neglected) in the garage since about 2013. We sent it out and it and had a lot of things wrong (age related neglect); needed a new ECU, Fuel Pump, Alternator, some new gaskets here and there (not head), and all of the other fluids, hoses, etc. you would expect.

One of the few remaining issues is as follows, for which I was hoping for some guidance.

Car starts right up no problem when cold. The occasional murmur that you expect from an older engine but as the car heats up to operating temp (80C on the nose) it starts to rough idle. If I try and put it in gear when its rough idling the car instantly stalls (D and R, no difference). It then will struggle heavily to start. The engine cranks no problem but will not catch. It does not throw ANY codes through the diagnostic reader and the CEL doesn't come on.

This weekend I'll be doing a fair amount of work on it on the usual suspects but I want to know if the crowd thinks I'm missing anything in descending order:

Crankshaft Position Sensor Replacement
Bosch Distributor Cap, Rotor, and dust shield
Spark Plugs change to Correct Bosch F8DC4
Going to check boot wires to spark plugs with ohm meter
I have new, extra, bosch ignition coil packs right and left as well though I may just hold onto these for now if I find the issue before this point.

Is there anything else you can think of worth checking?

Thanks in advance!

Edit: As a follow up. Wiring harness was changed in 2005 and i've tried to find answers to the issue in the search function but unfortunately nothing that matched my issues.

 

[gsxr]

Assuming you have checked all 6 powertrain computers with your "diagnostic reader" and there really are zero codes, it's pretty likely to be ignition related. Most likely caps/rotors/insulators. Tons of old threads on these parts & symptoms if you search. Based on some recent discoveries by @gerryvz, you may want to consider replacing the cam sprocket seal located behind the rotor bracket.

As discussed in other threads, I personally would not use new Bosch rotors, if only because the 3 bolts will not fit any metric or SAE hex driver properly. Highly recommend OE rotors only, made by Doduco, at twice the price. These were available reboxed by Beru but this changed a few months ago and now the only source is the dealer (or your favorite online discount dealer). I wouldn't use Bremi or Facet either. Gapping the F8DC4 plugs to 1.0mm doesn't hurt but will not cure the problem you describe.

You could pinpoint the issue with a digital scanner that will show ignition voltages on each cylinder, but starting with new caps/rotors/insulators is probably a good idea. I doubt the crank sensor is responsible; while it can cause a no-start condition, it doesn't cause misfiring.

 

[nocfn]

Inspect the cam seals behind the insulator and replace it should there be any trace of oil behind there. Gap plugs to 1mm out of the box.

 

[jsmulhollandiv]

Thanks for the response. I should clarify when I say misfire. I get a gentle pop (not sure how else to describe) occasionally when the engine is warm and cranking, but it is a no start condition until the engine cools down. I pop the hood and let the engine cool for 30 minutes and it starts up no problem until back to 80c.

Unfortunate about the Bosch Rotors. Not much to be done about it except to cough up the money the better ones. Any known issues with the caps? or Mixing Bosch Caps with Dealer rotors? Will re-order as necessary.

Anyway: I will go through the replacements above one at a time and post back. I will double check gaps on plugs to make sure they're at 1mm.

 

[nocfn]

The aftermarket beru have changed - So if you want the best, dealer IMO is the way to go caps and rotors.

 

[gsxr]

A no-start condition when hot, COULD be the crank sensor. In that case, I'd try the crank sensor first, just to see what happens.

However, the cap/rotor/insulator issue can have the same symptom, but usually only 10-20 mins after a cold start (shortly after reaching operating temp). But if you wait 30+ minutes and it starts again, and it runs perfectly for the rest of the day, starting every time... that's not crank sensor.

No issues mixing Bosch caps and OE/Doduco rotors. The dealer caps are also Bosch, but at twice the price of Bosch aftermarket. Beru caps are OK (those haven't changed, yet, AFAIK).

Plugs are pre-gapped to 0.8mm so you'll need to open up the gap a little. Don't use a ball-end Allen wrench to remove the old rotors or you could strip the socket heads.

 

[jsmulhollandiv]

interesting. Whats the best way to check you think? Ohm meter and see if i get a crazy high reading? Or just replace out of an abundance of caution (carefully so not to break it off in there)...

It unfortunately doesn't run flawlessly the rest of the day but rather just restarts the cycle. 1. Warm up. 2. Can't start again. 3.Cool Down. 4. Starts no problem. Wash, rinse, repeat.

Never use those ball end allen tools... i've never had good luck with them... ever

 

[gerryvz]

What diagnostic reader are you using? The push-button and LED under the hood? Because that only provides codes for ONE of the systems. If you have a code reader, then I would clear all codes, drive the car, and see what comes back. That would be my first step. This will give you a good direction as to what to pursue.

I think you're going to find that the caps and insulators are going to be in miserable condition on the inside of the caps, and the back-side of the insulators. When you pull the insulators off, check the cam oil seals behind them for any obvious oil leakage. Light oil mist/dust likely isn't a problem. You'll see oil leakage if the seals need replacing.

Have you checked fuel pressure? Specifically at the fuel pressure regulator on the fuel rail? There is a spec for fuel pressure while the car is running, as well as for it to gradually leak down over time when the car is not run.

 

[jsmulhollandiv]

One of those OBD1 blinking light code reader blinkers you can get on ebay (Mercedes OBD1 Diagnostic code reader R129 W140 500E W124 SL600 SL320 SL500 S320 | eBay). Seems to work relatively well.

Yeah. I'm curious to see how bad its going to be. One of my thoughts is moisture in the caps that evaporates when warm and then stops the caps from working.

I have not checked fuel pressure. I'll be honest, i'm not even sure how. Probably something somewhere on this site! Worth replacing FPR out of an abudnance of caution anyway?

thanks for all the help guys! I've been a guest ghosting these forums but i figured it was time to actually join!

 

[gerryvz]

OK, so you were able to test ALL of the pins that control the car's systems, then. What codes did you get on each system? Did you reset the codes? Have you driven the car at least 50-100 miles? Have you re-tested for codes? Have any codes come back?

Normally bad caps and insulators get better as the car is run, after starting out running rough for the first 5-10 miles until things warm up and the built-up moisture evaporates.

 

[jsmulhollandiv]

There were ZERO codes to reset from from all of the pins. it had just come back from the shop for the major work so I guess this shouldn't be surprising for most systems but it DID surprise me that nothing was thrown by the no-start when hot.

I have not driven that far yet. I wanted to change the plugs/caps/rotors etc before taking it for a long drive around town in case it really packed it in. I will take a longer drive this weekend and test for codes and report back!

 

[gsxr]

It unfortunately doesn't run flawlessly the rest of the day but rather just restarts the cycle. 1. Warm up. 2. Can't start again. 3.Cool Down. 4. Starts no problem. Wash, rinse, repeat.

Ah, that helps. If the engine dies every time it reaches operating temp, there's a decent chance the crank sensor is failing. As a test, next time the engine dies and won't re-start, measure the resistance of the sensor. Normal is 800-900 ohms or so, measure your new spare for comparison. If it's way off (like several thousand ohms, or more) when hot, you found your culprit.

 

[nocfn]

a common issue on the 420 SEL W126.

 

[sheward]

I too have recently bought the same year SL with the same exact problem. Also, the car was not used frequently before I purchased it. Replacing the insulators behind the rotors as was noted by everyone upstream solved the problem as I suspected it would. I am also going to replace the crankshaft position sensor just because.

drew

 

[jsmulhollandiv]

Good afternoon: an update.

I’ve been slowly moving down the list. I replaced the crankshaft sensor no problem. Seemed to help a little bit but didn’t cure the issue.

I popped off the distributor caps and they were in absolutely horrid. Black arc-ing marks, green build up, and looks like some yellow mold on everything. Black plastic around bolts was shattered. Rotors were covered in junk too. Problem is that I wasn’t able to get rotors off and they pretty clearly need to come off. Is there any harm using some penetrating oil to get the bolts loose? I don’t want to strip them.

For now I reattached the distributor and it did seem to start when hot. I will re-try tomorrow after somehow getting the rotors and dust cover off.

next stop is the plugs.

 

[sheward]

I suggest a search on the subject here. Problems with overtight rotor bolts as well as ill fitting allen wrenches is discussed in depth. Penetrating oil will do no harm but is unlikely to help. The bolts are seldom corroded. Do not use a ball end wrench. If all else fails after reading up on others comments be assured that drilling the heads off will work. The problem is tension and sloppy tolerances in the hex cavity, and likely not corrosion.
I found that some of my allen wrenches fit better than others. An old mechanics trick is to introduce metal shavings into the hex head for a better bite. There are even products sold for this now. Just be careful said shavings don't end up where they should not. You need to replace the insulators, rotors and caps with products recommended in previous discussions.

drew

drew

 

[Duh_Vinci]

Cheers all!

Can't really add much to what was already said above... I sometime experience minor issues with ignition too (same as @jsmulhollandiv and @sheward car, 1995 SL500). My issue definitely moisture buildup related and only after prolonged parking and short drive thereafter (parked for 2 weeks, 10 min drive to the store, off... come back from the store, start: misfires, does not completely die, but certainly missing for a short period of time)

I've replaced rotors and caps, Bosch 2 years ago. Gapped plugs to 1mm. But I can pretty much guarantee, in my case, after 6-8 months, if I remove the caps for "cleaning" there will be moisture build up. If I drive it daily, it rarely happens, almost doesn't happen. Still, every 6-8 months, I open them up, and with a fine sand paper to file down the points gently, clean everything up and good to go for a while again.

My next step, I seriously considering doing the what @robm.UK did, can't find the post here, but this is his write up on BW Condensation in distributor caps

As for rotor bolts, originally, mine were tight and as mentioned over and over, the standard allen tool didn't work. Can't remember the exact size, but I ended up using slightly oversized "star" tool gently "tapping" it into the hex head. Luckily it worked.

Regards,
D

 

[Jlaa]

Thanks for linking to that test where 12 more slots were cut in the cap!

 

[gsxr]

My next step, I seriously considering doing the what @robm.UK did, can't find the post here, but this is his write up on BW Condensation in distributor caps

Thanks for the link - I had not seen that before. While fascinating, I still believe it's a Band-Aid applied and still not identifying the root cause. Back in the mid-90's, these engines were not suffering from constant misfiring in humid environments. Why are they doing so 20 years later? Something changed, what is the something?

Edit: Also make sure to read post #13 in that thread. Copy/paste below:

It's not your caps, it's your coils!!!!​

Everyone forgets that these early distributor engines also have two ignition coils. They go bad and are extremely prone to moisture sensitivity when they do.​

​

I had the EXACT issues you're describing here on my 1995 W140 which has the same engine as your car. Every time it rained my car would get a misfire and rough idle. It would even happen when I drove through big puddles sometimes or on particularly humid days. It was infuriating.​

​

I changed out the caps and rotors. Twice. Changed the dust caps behind the rotors. Changed the plug wiring. Spark plugs. I put dielectric grease all over the cap seals to try and keep moisture out. I read every forum post I could. I chased this problem for nearly TWO YEARS and was at my wits end, figuring I just couldn't drive the car in the rain anymore.​

​

Finally when the issue began happening even when the car was bone dry, I had an epiphany -- the ignition coils.​

​

I removed them from the car and -- holy crap -- they were beyond oxidized and one was even splitting open along its seam. That was clearly the problem. I ordered a set of two new coils and have had exactly zero issues since, and that was about a year ago.​

​

Inspect your ignition coils, I'd bet good money that's where your problem really is.​

 

[sheward]

Agree. It seems to me Gerry is on to the answer with the cam seals. Even though leakage may not be visible it certainly could be present.
Dave, have you (or anyone) experienced this issue after changing cam seals? Could a plugged EGR valve as recently discussed be raising crankcase pressures? Surely many of these need cleaning by now.

drew

 

[gsxr]

So far, the only engine I've changed cam seals on, I sold years ago so I have no data. But, I plan on replacing those seals on other engines in the future, either when they're apart for other work, or if the mystery liquid re-appears after cleaning.

 

[nocfn]

I have only had about 60 minutes of total run time with new cam seals- rotors - caps, armatures and cam magnets. So far, each cold and warn/hot start is smooth as butter. I have NIB coils at the ready.

 

[gerryvz]

I also believe that coils are a VERY often overlooked issue, and should be replaced at least every 100,000 miles out of hand.

The post that @sheward was referring to that I made is here: Ignition problem traced to faulty insulators behind distributor caps | M119 Engine

 

[Duh_Vinci]

Thanks for the link - I had not seen that before. While fascinating, I still believe it's a Band-Aid applied and still not identifying the root cause. Back in the mid-90's, these engines were not suffering from constant misfiring in humid environments. Why are they doing so 20 years later? Something changed, what is the something?

Edit: Also make sure to read post #13 in that thread. Copy/paste below:

It's not your caps, it's your coils!!!!​

Everyone forgets that these early distributor engines also have two ignition coils. They go bad and are extremely prone to moisture sensitivity when they do.​

​

I had the EXACT issues you're describing here on my 1995 W140 which has the same engine as your car. Every time it rained my car would get a misfire and rough idle. It would even happen when I drove through big puddles sometimes or on particularly humid days. It was infuriating.​

​

I changed out the caps and rotors. Twice. Changed the dust caps behind the rotors. Changed the plug wiring. Spark plugs. I put dielectric grease all over the cap seals to try and keep moisture out. I read every forum post I could. I chased this problem for nearly TWO YEARS and was at my wits end, figuring I just couldn't drive the car in the rain anymore.​

​

Finally when the issue began happening even when the car was bone dry, I had an epiphany -- the ignition coils.​

​

I removed them from the car and -- holy crap -- they were beyond oxidized and one was even splitting open along its seam. That was clearly the problem. I ordered a set of two new coils and have had exactly zero issues since, and that was about a year ago.​

​

Inspect your ignition coils, I'd bet good money that's where your problem really is.​

Well yesssss, what is that "something"

I've spent few hours on this site today reading ignition related topics... Learn something new every day! Before I purchased this car, original owner had it in 3 shops. Plugs, rotors, caps, wires and coils were replaced (along with throttle body and main engine harness). I looked at the coils with connectors few months back, all dry/clean/corrosion free still. The only thing left for me to check is the signs of oil around those seals - never paid any attention to those. I will have to inspect those cam seals to be sure soon.

Regards,
D

P.S. Thank you all for sharing the "know how" and the tips, diy and the tools info needed. This is the most enjoyable ownership of any car I've had in the last 30 years!

 

[gsxr]

D, no mention of the insulators on your car... have they been removed for inspection on the back side, even if replaced?

 

[Duh_Vinci]

D, no mention of the insulators on your car... have they been removed for inspection on the back side, even if replaced?

Dave, this is a “failure” to inspect in my part. I knew these were replaced along with everything else by the prior owner, I have only visually inspected the forward facing section (looked brand new) but after seeing few threads here today to what the back side can look like, particularly @emerydc8 on his 94 - I know better now!

Next go around when I get some free time, along with the cam seals inspection!

 

[jsmulhollandiv]

Hi all,

Reporting back. So far so good after caps have been replaced. Rotors and adapters have been replaced too. Onto to the next issue which is something @gerry pointed out above. The right bank, behind the dust shield, was gross from moisture behind the dust shield but generally not oil. The left bank however was basically an oil can.

I reviewed the thread about replacing cam shaft seals but was able to get a good DIY instructions. Seems I might need a tool of some sort? I’ve ordered the new seals but is there an obscure post in here that covers it? Searching for it here and the much maligned benzw, yielded nothing particularly clear.

also weirdly enough... my upper mesh on the MAF was completely crumpled on one side. I have no idea what could’ve caused this... hopefully sensor is fine. Ordered the mesh too.

 

[gerryvz]

Did you also replace the insulators (what you call dust shields) behind the rotors? If not, you MUST. They are insulators because the function is not to protect from dust/dirt, but to electrically insulate the inside of the cap and the rotor (the electrical paths) from shorting out on the cylinder head/front cover. It's a common misconception.

@emerydc8 has done this cam seal replacement job with the front covers on the car, and can comment and/or point you to where he posted about this. he created a special tool to do this that worked effectively.

A special tool from MB is NOT required, especially if you follow emerydc8's instructions.

Personally, if it were me, I would remove the front covers and do this job on the workbench. You would have to buy a tube of MB orange anaerobic sealant (or its aftermarket Loctite equivalent), but there are only like 5-6 bolts that hold each cover onto the front of the head.

I used a 30mm socket as a mandrel to remove and press in the new seals, as detailed here.

RESTO PROJECT: M119 / W124 / E500 Engine Top-End Refresh | Member Roadtrips and Project Journals

"12.5 dungarees" - man, that's a lot of pants...

www.500eboard.co

You should also check closely to see that your cam adjuster solenoids are not leaking oil from between the two halves, or from the plastic connector. Should be pretty apparent if you have leakage there.

 

[jsmulhollandiv]

What diagnostic reader are you using? The push-button and LED under the hood? Because that only provides codes for ONE of the systems. If you have a code reader, then I would clear all codes, drive the car, and see what comes back. That would be my first step. This will give you a good direction as to what to pursue.

I think you're going to find that the caps and insulators are going to be in miserable condition on the inside of the caps, and the back-side of the insulators. When you pull the insulators off, check the cam oil seals behind them for any obvious oil leakage. Light oil mist/dust likely isn't a problem. You'll see oil leakage if the seals need replacing.

Have you checked fuel pressure? Specifically at the fuel pressure regulator on the fuel rail? There is a spec for fuel pressure while the car is running, as well as for it to gradually leak down over time when the car is not run.

Hi Gerry,

Do you happen to know the part number for the small (6 inches or so?) hose that goes from the FPR to roughly near the 8th piston? I discovered that this hose has minuscule hairline crack when cold, which seems to self seal when warm. I can't seem to find on any information on it. Its in terrible condition and I don't want it to fail completely.

Edit: It is the vacuum line.

 

[Jlaa]

Hi Gerry,

Do you happen to know the part number for the small (6 inches or so?) hose that goes from the FPR to roughly near the 8th piston? I discovered that this hose has minuscule hairline crack when cold, which seems to self seal when warm. I can't seem to find on any information on it. Its in terrible condition and I don't want it to fail completely.

Edit: It is the vacuum line.

are you talking about this?

• Bosch 0280-160-587 MB 000-078-18-89 Fuel Pressure Regulator
• Rubber Hose piece 1 that goes to FPR - 117-078-02-81 - 90° degree "L" shaped fitting (long, requires trimming for FPR use)
• Rubber Hose piece 2 that goes to FPR - 117-078-05-81 - 45° "V" shaped fitting
• Yellow Check Valve - 116-276-09-29

 

[jsmulhollandiv]

are you talking about this?

• Bosch 0280-160-587 MB 000-078-18-89 Fuel Pressure Regulator
• Rubber Hose piece 1 that goes to FPR - 117-078-02-81 - 90° degree "L" shaped fitting (long, requires trimming for FPR use)
• Rubber Hose piece 2 that goes to FPR - 117-078-05-81 - 45° "V" shaped fitting
• Yellow Check Valve - 116-276-09-29

View attachment 117093

Yes thank you! Exactly what i need. Its so gucked up, I didn't even realize it was two pieces of hose...

 

[gerryvz]

Make sure you get all of the pieces, including the yellow plastic piece.

 

[robm.UK]

Thanks for the link - I had not seen that before. While fascinating, I still believe it's a Band-Aid applied and still not identifying the root cause. Back in the mid-90's, these engines were not suffering from constant misfiring in humid environments. Why are they doing so 20 years later? Something changed, what is the something?

Edit: Also make sure to read post #13 in that thread. Copy/paste below:

It's not your caps, it's your coils!!!!​

In the interest of balance, post #28 of same thread: -

Well robm.UK I cut the distributors just like you did and, IT WORKED . Its rained a few times and no problems.
Thank you very much for the info I was about to sell this car because of this problem . Thanks to you i will keep it.
Thanks
John

 

[robm.UK]

Well, I joined a few months ago, and this is my second post.

Just wanted to say hello to all. The knowledge and expertise on this forum is second to none.

I am the author of the report that @Duh_Vinci posted. He only had the cut down version. I will post the full report (first need to get it off my laptop) which explains the root cause in more detail.

Essentially the root cause is due to a combination of factors: - the heating and cooling cycle, the dissimilar thermal properties of the materials, the psychrometric properties of ambient air, and the lack of appropriate vents to allow moisture to escape. The symptom: - the formation of a dew point at internal surface of the distributor cap and of course misfiring.

The condensation problem is NOT directly due to a physical change that occurred over 20 years. Although that is not to say that changes did not occur (cam journal oil seals wear, blow by gases increase as cylinder bores wear etc).

Very early on in the life of the M119, MB issued a bulletin to address running problems due to moisture in the distributor caps. MB advised that this was related to the design of the Doduco distributor caps (black caps) and recommended changing to Bosch. One might conclude that this was the band aid.

Cutting additional vents could be considered a permanent fix IMHO.

 

[robm.UK]

A link to the full report on fixing the misfire problem on CIS-e engines can be downloaded HERE

 

[Jlaa]

A link to the full report on fixing the misfire problem on CIS-e engines can be downloaded HERE

Wow, this seems exceedingly well researched and thought through. Thanks so much for sharing it.

 

[robm.UK]

Don’t mention it.
I have profited from the expert advice of 500eboard and Benzworld’s knowledgeable members.
So it’s the least I could do to repay the favour.

Next project: - serpentine rubber bush type belt tensioner conversion to spring tensioner, as used on 190d 2.5 etc.

 

[gerryvz]

Banzworld? Knowledgeable members? Really ?!?

 

[robm.UK]

Yeah, if they weren’t knowledgeable, I wouldn’t have profited I guess.
Fine fellows.

 

[2phast]

The no start when hot normally indicates a crank position sensor but, if your caps are extremely worn, the car will start when cold but when it heats up, it will start to sputter and stall and won't restart. The plastic on the caps will expand when hot and if the gap between the rotor and cap points is too great, your engine will just quit on you and won't restart till the caps cool down (and shrink). So to avoid this problem with the caps, do not clean the contacts with anything except a qtip and rubbing alcohol. Using a steel or even a brass brush is just asking for trouble.

 

[gsxr]

Next project: - serpentine rubber bush type belt tensioner conversion to spring tensioner, as used on 190d 2.5 etc.

The M119 belt tensioner upgrade was covered years ago on this forum, for the 119.97x engine. I don't know if the 119.960 will be different or not.

 

[robm.UK]

Thanks Dave. Will take a look.

 

[gerryvz]

In the interest of balance, post #28 of same thread: -

Well robm.UK I cut the distributors just like you did and, IT WORKED . Its rained a few times and no problems.
Thank you very much for the info I was about to sell this car because of this problem . Thanks to you i will keep it.
Thanks
John

Well, I joined a few months ago, and this is my second post.

Just wanted to say hello to all. The knowledge and expertise on this forum is second to none.

I am the author of the report that @Duh_Vinci posted. He only had the cut down version. I will post the full report (first need to get it off my laptop) which explains the root cause in more detail.

Essentially the root cause is due to a combination of factors: - the heating and cooling cycle, the dissimilar thermal properties of the materials, the psychrometric properties of ambient air, and the lack of appropriate vents to allow moisture to escape. The symptom: - the formation of a dew point at internal surface of the distributor cap and of course misfiring.

The condensation problem is NOT directly due to a physical change that occurred over 20 years. Although that is not to say that changes did not occur (cam journal oil seals wear, blow by gases increase as cylinder bores wear etc).

Very early on in the life of the M119, MB issued a bulletin to address running problems due to moisture in the distributor caps. MB advised that this was related to the design of the Doduco distributor caps (black caps) and recommended changing to Bosch. One might conclude that this was the band aid.

Cutting additional vents could be considered a permanent fix IMHO.

A link to the full report on fixing the misfire problem on CIS-e engines can be downloaded HERE

I did want to flag the fact that one of our long-time members, @500AMM of Norge, came up with this solution more than 5 years ago and it seemingly worked at that time. So I view the curent dialog and findings from @robm.UK as further confirmation of what had already been posited.

Stripped bolt heads on distributor rotors: How to remove?? HELP | M119 Engine

Hi guys, I tried to replace my old rotors and could not do it :hammerhead: It is 3 mm hex but it spins inside of a bolt (either bolt was crap or it was too tight) anyway now tree bolts are completely gone:pissed: , they are round inside instead of angular 3mm hex. :fun: So ... any ideas how...

www.500eboard.co

 

[robm.UK]

Those Norge guys are clever.

Thanks for sharing that. I had not seen that before.
I’ve got a heap of links to threads from all over going back before 2009. All variations on the same theme..

I ain’t claiming to be Neil Armstrong

 

[nocfn]

 

[robm.UK]

That’s a mighty fine rocket you got there

 

[nocfn]

That is what she said!! ^^^^^^^

 

[sheward]

The good folks here like to say pictures or it didn't happen.

drew

 

[robm.UK]

Here is an extract of the MB USA service bulletin about the Doduco distributor caps.

View attachment 117245
There is another thread here about Beru being re-boxed Doduco parts.

I used to prefer Beru because the amide lacquer finish helped with the condensation problem. But the benefit is no longer significant if you do the modification. Bosch or Beru, take your pick.

One thing I would say about Beru. I had a Beru cap fail 7 or 8 years ago. The centre electrode came adrift. The plastic around the electrode cracked.

Here is a photo of the Beru electrode with the plastic insulation removed.

View attachment 117246

The white is a ceramic layer. I was surprised that I could pull the end off very easily.

View attachment 117247

Which is not good.

The black part below is a rigid plastic coating over a very thin wire coil wound on a white glass fibre resin rod.

View attachment 117248

The above photos are of the old Beru that failed,that I have had hanging around in my garage.

I checked out the other electrodes. Same story. Easy to pull the terminal ends off the rod.

So I also checked out an old Bosch cap. I could not pull the ends off. They were securely crimped on. My feeling was that the Bosch was better constructed.

I will post some photos of the Bosch later.

 

[robm.UK]

The fine wire coil gives roughly 1200 ohms of resistance.