No Power/Acceleration. Low Idle

[Philip]

Hey guys

I’m from Germany, please ignore my bad English.

I searched literally the hole Forum about my Problem. Maybe some of you can help me.
My SL 500 with M119 LH Jet got a Problem.

It Starts good but after the Warm up the Idle goes down to like 550 RPM and when I put it in Gear it goes o 450-500 RPM (nearly dies).
It also got no Power/Acceleration. It feels like 50hp or something. Sometimes it makes a Downshift but this also doesn’t feel like 300 hp.
The Car smells hard like unburdened Gas in Idle. In Neutral I can easily rev the car it got no Misfires or Something it Revs pretty good.

When I first bought the Car it had ASR Lamp and Limp mode. I cleared the Problem with a new Wiringharness from Motor and from Throttlebody Harness. So now no longer ASR or Limp mode.

Yesterday I checked the Codes with an Blinkcode reader, all old codes seemed like they were caused by the bad Wiring harness. After deleting all Codes the Fault list was clear after driving some meters.

The Previous owner changed some Parts:
Ignition cables-NGK
Disturber + Cap - Bremi (I don’t like that)
Spark plugs NGK
Fuel Pump+Filter
Crankshaft sensor

Maybe someone can give me a Tip where I can look next to find the Problem.

Unfortunately I don’t got any Software or HHT/Stardiagnose. I only have an Blinkcode reader.


hope all of you have an nice Day

 

[gsxr]

If there is an odor / small of unburned fuel at idle, that's not good. Sounds like severe over-fueling / excessively rich mixture. If there are NO misfires and it runs smoothly, something is wrong with the mixture formation.

What happens when you disconnect the MAF and try to drive the car?
Have you checked fuel pressure at the fuel rail, with a gauge, with engine running?
Have you checked for any vacuum leaks?
How old is the oxygen (O2) sensor?

BTW, welcome to the forum!

 

[Philip]

If there is an odor / small of unburned fuel at idle, that's not good. Sounds like severe over-fueling / excessively rich mixture. If there are NO misfires and it runs smoothly, something is wrong with the mixture formation.

What happens when you disconnect the MAF and try to drive the car?
Have you checked fuel pressure at the fuel rail, with a gauge, with engine running?
Have you checked for any vacuum leaks?
How old is the oxygen (O2) sensor?

BTW, welcome to the forum!

Thanks for you’re answer.

I’d only runs smoothly when I rev it.
When I disconnect the MAF the idle stays the same but it doesn’t rev any better. It got some kinda delay when reving. I didn’t drive it without the MAF maybe I try it later.
Fuel Pressure is on my list just need that adapter to do it.
I found no Vacuum leaks. Is sprayed everything.
The oxygen Sensor… I don’t know. I only got the car 1 month ago. The sensor is from Bosch.

Is there another method to test the MAF ?
Do you think the Catalytic can be the Problem ?

 

[gsxr]

The only valid method to test the MAF is viewing live data on HHT/Stardiagnose. Do you know anyone with SDS? Or, you can buy a full kit for about $750 USD for the "M6+" setup, including the laptop/tablet and pre-installed software.

Plugged catalytic converter could be an issue, although that usually wouldn't cause poor idle, or cause a rich mixture. To test, remove the crossover pipe from the driver side manifold to the passenger side. This will be loud (open exhaust) but if there is no change, it's unlikely to be plugged cats. The proper test is using an exhaust backpressure gauge to measure pressure upstream of the catalysts.

You should also remove both valve covers and check camshaft timing. Since this is a "new" purchase, you need to do this anyway, to inspect for broken chain guide rails. If the cam timing is way off that could cause poor idle.

Also verify the EGR valve is not stuck open.

 

[emerydc8]

Do you have the correct spark plugs (F8DC4) gapped to 1 mm? What grade of fuel?

 

[gerryvz]

Sounds to me like your EZL is partially kaput, and your engine is only running on four cylinders. I had this same exact problem back in 2009 and my EZL was half dead. Try another 5-liter EZL (ignition computer) unit.

Having un-burnt fuel smell coming out the exhaust is a CLASSIC symptom of this problem.

Also, make sure your new wiring harness is correctly routed to each plug.

 

[gsxr]

I may have misunderstood the original post which mentioned "no misfires".

It definitely could be 4 cylinders (1 distributor) not firing at all. Try starting the engine with 1 coil disconnected, then try the other coil. If it runs the same on only 1 coil, your problem is the ignition system.

 

[Philip]

Thank you all for your response.
Tomorrow I go back to the car with a clear Head and the Checklist you Guys gave me.
@gsxr unfortunately I don’t have any diagnostic tools and know nobody with one. I want to try everything without buying expensive Software. Maybe I can get it ready this way.
I hope all of you guys have a nice evening. I will come back tomorrow with some Updates.

 

[gerryvz]

The @gsxr's test above with regard to disconnecting each coil, one at a time, will tell you immediately whether the ignition is a problem or not. If it is, then it can only be either the coil, the EZL, the wire(s) or the distributor cap+rotor connecting that side (if the spark plugs are good, which I am sure is not your problem). You can isolate each of those with no software or tools. The EZL is the computer that controls the coil, which then controls one side's cap and rotor.

 

[nocfn]

You are in good hands Phillip

 

[Philip]

Hey guys.
Just went to the Car and I can’t believe it.. I am so dumb… the Car only runs on 4 Zylinders. The Ignition on the hole right Bank is dead. I measured the Cable "resistance" (I don’t know if this is the right description) they are all good at 2kOhm. I just ordert me some new Bosch Disturber and Caps. Hope this will help. Right now there are some BREMI Disturbers and Caps mounted.
One Question: the Cables that comes from the Ignition Spule are different. I’m gonna show you some Photos. I think the first Cable is the Wrong one. It unplugs so easily and the other one seems like it’s better in Quality and got more contact to the Spule.

@gerryvz if the EZL is the Problem do you know what this thing Cost me ?

Wish you all a nice day

 

[Philip]

 

[Philip]

 

[Philip]

I Changed the Disturbers from left to right. Now the right bank fires up and the left Ignition is dead. I’m pretty sure the Disturber is dead. I will give an update when the new parts arrive.
I just want to thank you for your response. In Germany there is no Forum where people are so friendly and nice.

 

[r44raven]

As @nocfn says, you're in good hands here!

 

[gsxr]

This connector is correct for the coil:



This connector should only be used at the cap:

 

[Philip]

This connector is correct for the coil:
View attachment 210139


This connector should only be used at the cap:
View attachment 210140Okey then it seems like it’s also the wrong cable. I will replace it thank you.

 

[gsxr]

I Changed the Disturbers from left to right. Now the right bank fires up and the left Ignition is dead. I’m pretty sure the Disturber is dead. I will give an update when the new parts arrive.

Which parts did you swap left to right? The cap + rotor?

The wrong connector / wrong cable at the coil isn't helping, replace that with the correct type.

I just want to thank you for your response. In Germany there is no Forum where people are so friendly and nice.

Happy to help! Sad to hear there isn't a good support forum in Germany.

 

[Philip]

I switched only the Rotor from right to left.
I ordert now the correct cable from the Coil to the Cap. I knew something is wrong if one looks different than the other

 

[gsxr]

I switched only the Rotor from right to left.
I ordert now the correct cable from the Coil to the Cap. I knew something is wrong if one looks different than the other

I'm not a fan of Bremi (or Facet) brand rotors, or caps. New Bosch rotors should take care of the problem.

While you are in there, also cut additional vent slots into the caps as discussed in this thread, and make sure to eliminate any oil leaks from the exhaust camshaft seal, and from the intake cam advance solenoid / magnet.

 

[Philip]

Yeah I’m also not a fan of these aftermarket things. I don’t know why the previous owner did that. I ordert Bosch now.
Yes I already saw this thread. I will definitely take care on this.
I give updates as soon the Parts arrived

 

[Philip]

Hey guys,
I’m happy. Changed the rotors+Caps. Everything fine. I test drove it around the Block and everything works fine.
Now I can go to the German Checkup (TÜV) and then I can finally drive it.
Thanks again to all of you.

 

[nocfn]

Be sure you drive it in well temperature so you don't get any condensation issues