Car Stalls PLEASE HELP!!!

**GRANDPRIXFOOL01** · 10-21-2008

Ok so this has been quite an ordeal for me. I did a top swap and shortly after it started to stall out randomly on me. At first I had no tach ans the tcs light came on. So naturely I replaced the cps, which eventually solved that. But the car still would stall out on me randomly and be a ***** to get to start back up. One time this happened I was on the side of the highway and I began to unplug sensor to try and identify the problem. I got to the map sensor and it started right up. I hooked it back up after I got it running and drove away. Shortly after it stalled again and I went right to the map and unplugged it and it started right up. So I replaced the map sensor with another gtp one. The car was all good for about a week or so, and then started to stall out again! This time I depressed the schrader valve and had no pressure. So then I replaced the fuel pump with a new 01 gtp one. Hoping this was the problem I took it out and the f*ing thing stalled out on me again! This time I pop the hood when the car stalled and key on and saw fuel spraying out the schrader valve! I also replaced the fuel pump relay as a last effort still nada. I replaced the core with just a regular one out of a valve stem for now. Havent had the pleasure to drive it and find out if this was the problem yet. Everytime it stalls I am on the highway or cruising above 60 or so and the rpms drop to an idle and if I try to rev it up it will stall out. Last night after the fuel pump I almost got dead a few times because there was no shoulder to pull over to. So I had to get out push. I really need this fixed. Any advice would be greatly appreciated. Thanks guys.

**Sabrewings** · 10-21-2008

Ever bother to replace the FPR?

**SyntheticShield** · 10-21-2008

Fuel Pressure Regulator or MAF sensor maybe?

**GRANDPRIXFOOL01** · 10-21-2008

New lq4 maf. Could I use my old l36 fpr? How can I diagnose a bad fpr?

**SyntheticShield** · 10-21-2008

Ive never had a bad FPR, but from what I have read you can take the vacuum line off of it and if you find fuel there then its shot, but thats the only way I know of.

I know there is an improved FPR you can get in the parts stores. I have one but never got it installed and I dont have the part number off the top of my head.

**GRANDPRIXFOOL01** · 10-22-2008

So I would need to replace it with a gtp fpr then? I still have the one from my l36 fuel rails. That wont work to test it?

**Sabrewings** · 10-22-2008

Originally Posted by GRANDPRIXFOOL01

So I would need to replace it with a gtp fpr then? I still have the one from my l36 fuel rails. That wont work to test it?

Can't hurt to try, I suppose.

But, on RockAuto the part numbers are different for a 2004 Impala SS (L67) and 2004 Impala LS (L36).

**GRANDPRIXFOOL01** · 10-22-2008

I suppose Ill give it a try. Thanks for the help. PS. I like your sig.

**GRANDPRIXFOOL01** · 10-26-2008

Alright so I replaced the fpr and no luck. The car is still stalling worse than ever! Please tell me what should I do? I cannot have this continue to happen to me. Anyone with some tips would greatly be appreciated. thank you all for your input.

**SyntheticShield** · 10-26-2008

Well I would say check the MAF next, but you say that you have a new LQ4 maf on there, so the only other thing coming to mind are things like the fuel filter, or perhaps a vacuum leak or even a faulty EGR.

**BADAZGTP** · 10-26-2008

When I was having my stalling issue, it turned out to be my ICM. Had a bad EGR on mine and it didn't affect it any. Dealer said the only thing a bad EGR would do is throw a code.

**blueguy** · 10-26-2008

Just another side thought...how's the tune? There might be too much fuel being sent in @ a given time...hence you said cruising over 60. Could be something along those lines too b/c if it isn't then your MAF tables are WAY off with that LQ4. If you already tuned it then kewl...just my 2 cents though

**GRANDPRIXFOOL01** · 10-27-2008

I replaced the fuel filter with a zzp high flow unit, and I cant find any vacuum leaks. How can I test the icm? I should be getting another maf soon they said that they are sending another one out. What does the car use to moniter when the maf is unplugged? Because I unplugged it and it seemed to run worse, at least it stalled out at lower speeds. I bought a used lq4 mass airflow so I figured I would try talking to them and they had no problem sending me another one. I cant reuse my l36 icm right? Because I still have that one laying around. ZZP did tune it for the lq4 and my n* T.B.

**BADAZGTP** · 10-27-2008

You can take the icm by a parts store and see if they have the tester. I took mine by Oreilly's if you have one where you live. No guarantee that it will show up bad. They tested mine 3 times and came up good all 3. Guy said the icm's have thier good days and their bad. Take it and have it tested and see what the results are and if it says it's good, see if you can find one cheap at a scrap yard to see if it'll fix your problem instead of blowing the money for a new one.

**blueguy** · 10-27-2008

ZZP Tuned it...There is problem #1...they don't know their ass from a hole in the ground for tuning. Have you tables double checked. I guarantee that is where your problem is (or that MAF they sold you was s**t)...

**GRANDPRIXFOOL01** · 10-27-2008

I am expecting another maf to be in soon. What should I be looking for in the tune? My buddy has an hp tuner and I was gonna buy the credits for my car and try playing around with it myself. I am a newb to tuning so what should I be looking for and where should I start?

**blueguy** · 10-27-2008

I am not sure about the fuel trims in the PCM. I assume someone here might know

As am I...so have someone tune it for that knows what they are doing

**GRANDPRIXFOOL01** · 11-07-2008

UPDATE:Alright so the car is still acting up. There is no check engine light on but when the car stalls out with a scanner hooked up to it, it trips a p0101 code. "Mass Air Flow (MAF) Circuit Range/Performance Problem" I did replace the maf again. There are no vacuum leaks that I can find. The map sensor has been replaced aswell. I have a fwi and a 3in. offroad d.p. also. I have a vacuum line coming from the lim to the map and to the new fpr aswell. Any ideas?