All this driving was done on a race track. Well, i got up to 125 and was in 4th gear when i decided to let off. So i let off the gas, and then pushed the clutch in to slow down. Well, the RPM's kept falling and the car stalled. This has happened before, but never at those speeds. However, it only happens after i let off after high rpms. Whenever i do let the clutch in to stop after normal driving, the rpms fall to about 500 and then bounce back up to 1000 and it may do that a few times before it levels off. Also, sometimes while i'm just maintaining speed or gently accelerating the car will lug slightly. I've noticed all this began just after i installed the nitrous system, which may or may not be a coincidence.

I just changed my plugs yesterday because i thought they may be the culprit and i am still having the same problems. I installed nitrous in the car during spring break but i only made 2 short runs with it (on the stock platinum plugs). However, those plugs are out now and ngk TR55's are in.

The check engine light came on after tonight and i will pull the engine codes and post them tomorrow. I got the engine codes this morning... but they all were labeled as history codes. However, i'll list them anyways in case it might help someone:

PCM- P0108H P1514H P1571H
TCS- C1255H C1277H C1278H U1016H
BCM- B0432H B0502H B0503H B0507H B0508H B2428H B2527H B2567H B2587H B2588H B2592H B2593H B2597H U1255H U1096H
LPCM- B2282H B2284H U1064H
A1-RBCM- B2283H B2285H U1064H
RFA- U1255H

I realise that is a rediculous amount of codes... but they're all history codes. I'm so confused as to what's wrong. PLEASE HELP!


[Modified by WannaBe TT!, 12:01 PM 5/15/2003]

 

What mods do you have if any?

 

I have a hurst short throw shifter and a vortex ram air intake. I had nitrous installed... only sprayed twice though.

 

i am having the same problem, it is idling erratic and has stalled a couple of times, all at high speeds, my only mod is an intake

 

...someone.... anyone.... Please Help.

 

I guess i'll be flamed here, but check your battery for a leak. I don't know what year your car is but the bcm codes could be from a leak in you battery... as for the other problem :confused:

 

I got the same problem.
At idle, it has a hard time keeping the RPM at 700, especialy the first time I put in the clutch. It drops all the way down to 400 or 500. I also feel the lug at low RPMs. No NOS here (see mods in the sig).
I also thought it was the plugs, but after puting new ones (platinum) nothing changed.
The next thing I thought that might be wrong is having a leak in the intake. I replaced everything on the intake back to stock (except the throtle body) and still no dice.
Next I am thinking to replace the plugs (again) to NGK55 (copper), replace the wires and the fuel injectors.
The only other thing I can think of is the MAF sensor went bad.

 

interesting problems fellas, intersting

 

Suggest that you get someone with a TechII to review the codes/history. I had this issue when I 'upgraded' the H/C, and found a number of issues that needed to be addressed with an LSI edit.

 

Would a hole somewhere in the intake system cause this problem? I just thought of something else... i had to drill into the plastic thing that connects the throttle body to the intake to install the nitrous nozzle. The nozzle is still in, so there shouldn't be any serious leaks... but i'm just curious if that could have anything to do with it. *sigh*

 

An intake leak will definetly give you this symptoms, because the MAF sensor will metter the wrong amount of air that gets into the engine so the air to fuel ratio will get all f*** up. Maybe people with more technical knowledge will ping in to explain this one better.
Do you get any exhaust backfire/poping ?

Why aren't the sigs showing?


[Modified by cosmo, 4:14 PM 5/16/2003]