Panzerknacker

When under full throttle sometimes the car will have a loss of acceleration when im over 4500 rpm. It is sudden and then the car will have full acceleration again. Like I have had some sort of fuel cut off point or supercharger disengaged or something, maybe even a misfire. Like I said it will lose power then it will return immediatly on its own. It doesnt happen every time I floor the car, just occasionally. There are no CELs or any other warnings on the dash. Even tried turning off ESP to make sure it wasnt that. Been searching and reading old posts and couldnt come up with an answer.

I have replaced my stock IC pump with a CM30. The symptoms are much different than a bad IC pump, this is a sudden violent loss of acceleration then everything comes back. Doesnt sound like glycol contamination either, this is only at high rpms under full throttle. Throttle position sensor, maybe... but it is intermittent and car runs fine the rest of the time.

Im kind of leaning towards a belt slip. I replaced the belt when I did my pulley kit about 2k miles ago. What are the thoughts of the other c32 owners.

Robert AMG

iTrader: (1)

at low speed or high? over 120mph?

Panzerknacker

No not 120+ mph. Like, at the end a highway onramp is when its happening, so top end of 2nd and 3rd gear. Dont have anywhere to go to the top of 4th lol.

testknight

I know you said you already reaplced the pump...but to me that's exactly how my car acted with a bad one. It was sudden and violent, I'd floor it and then it was like someone put on teh brakes...my head would even bob forward, then after that I could hammer the peddle and it just would really take off (no S/C).

That said, you're probably right that its not, but the new pump could have failed (however unlikely) but just to make sure test this out with a cold car and see if you get the same issue, if it only occurs after a little bit of driving, then maybe it is the pump.

Panzerknacker

I had a bad pump, hence I replaced it. This feels much different. Maybe it is still something IC pump related. Pump not turning on when it should and thats why it is doing it when I first get on the highway. Or maybe a flow issue. Edit: I have made sure I hit enough RPM before entering the highway to ensure pump should have turned on.

It is kind of hard to recreate the problem thats why I am having a difficult time describing.

Velociabstract

ESP can cause what you describe, even turned off. Depending on the RPM, if you get too much wheel slip it will intervene (cut power drastically) or up shift early. At least that's how my SRT-6 reacts. I have a data logger which is how I found out what was going on. I hope thats all it is.

Les

Panzerknacker

Guess I would have to put it in dyno mode.

MRAMG1

What pulley did you go with?

It sounds VERY similar to an over boosting symptom, where the engine would shut down. Then it would come right back, because the sensor no longer sees boost.

Another, potential issue, could be HIGH IAT's due to the new boost, hence it pulls timing like a freight train, and as soon as you go back, it has power. So do you still have the stock HE?

Note: Over boost does throw a CEL.

When in doubt, call Jerry or Jake at Eurochrged. They have experienced it all on a C32, trust me, and they are VERY happy to help a fellow nut

One more note: If the belt was slipping, you would see black residue around the blower pulley fairly easy. Also, it would not shut off so to speak, it just wouldn't pull as hard. A shut off is something from the ECU I would wager.

Panzerknacker

I have a LET 185mm pulley, and I am running the stock HE. The thoughts had crossed my mind that it could still be reaching a IAT that was too high, or a boost level that the engine didnt like.

There are no CELs.

AirFrcd

FWIW - I have experienced the EXACT same issue as you have described, and have replaced every part under the sun to try and problem solve what is happening.

I am also running a belt wrap kit.

After speaking with various tuners, and spending well over $10K in the past 6 mos., the end result has been over boost...

Let's figure this out. The car runs fantastic 99% of the time, with the exception of this intermittent "hiccup" under WOT at the top of 2nd or 3rd...

Panzerknacker

The fix would be to run less boost lol.

But really to use a smaller pulley than a 185 would be an option. Or increase the amount of boost you hit before the ECU plays ref with your tuning. Although then you run the risk of damaging the motor. But MRAMG1 said over boost would cause a CEL and neither of us have one.

MRAMG1

Gentlemen:

Please contact Jerry on an over boost question. Jake and him are VERY knowledgeable on this issue. My statement on a CEL for over boost, is based on other posts from people on this forum. PLEASE use Jerry and Jake for issues. They really are great guys that live for our toys.

Panzerknacker

Sorry to quote you like the, well word on the streets is that it causes a CEL.

MRAMG1

No problem my friend. It's just when I ran a bigger pulley, I NEVER had any issues. It was however smaller than 185

I hope you get it straighten out my fined

Good luck, and happy holidays

TemjinX2

if you overboosted you would get a cel. If your on stock spark plugs, then its probably your gap. I had similar issues, it was really bad to the point where i misfired at 120mph. The solution is to get smaller gap spark plugs. Preferably .34-38 gap. I just changed mine out today...hopefully i can test it out in the dyno...soon

AirFrcd

I am already running the coldest plugs available with the narrow gap - as suggested by EuroTech.

That is not it.

Lenin

Is there any way you can do some live data logging? There is a little under $100 gizmo from http://www.carchip.com/ that can log basic OBD2 data including MAP readings. I run a 181mm pulley and only once got the over boost CEL during some runs at Atco this past November. But the CEL does come up when you usually get to the 22+ PSI area.

razormb

Its the Tune. You guys need to go back and talk to Jerry. I used to have the same problem.

Panzerknacker

Here is the response I got from Jerry. He is helpful and knowledgeable. Ill send my ECU back to them when I get a chance.

trbo2nr

EXCELLENT! Thanks all with the responses. I need to send mine back to Jerry- since he did mine too. Who has his current e-mail? I have his card taped to my ECU but think the info is old. I'll dig through my old e-mails in the meantime.

Bob

loudandheard

Did you do a coolant flush when you changed out pump? You could have an obstruction.

francoisisp

im runing NGK plugs and magnecor wires i seem to have his somewhat of a stall after reaching 120+mph momentarily did changing the gap do anything? i changed to IC pump in september and its not the same problep i got when the ic pump was bad any solution ?

320 dreamer

is the 185 the only mod with the tune/ thats way impressive if your bangin 400 ft/lbs with just a tune and 185!!!

60n5pt1

Yep, happened to me a couple of times, just as I was getting on the freeway and close to 60-65 mph. It's as if the car had a hiccup, drops rpm suddenly and shifts to next higher gear. I thought it was a belt slip. And usually when I first start the day. It eventually went away and hasn't happened
yet again.

TemjinX2

i havent tested yet... i blew a gasket or seal a couple of days ago. So i gotta wait till its fixed.