Mechanics

WANTS TO STALL

Chevrolet Avalanche

2003 Chevrolet Avalanche Z17 w/ 5.3L V8 55,000 Miles.

So I am sitting in a parking lot with the AC on at idle for about 15 minutes. I put the truck in Reverse and it dies. There have been no previous problems. I attempt to start and no power. I check the battery, etc. And find the PCM1 Fuse was blowen. I changed it and the truck started.

Now ever time I put it in gear it throttles way down (like 200 RPMs), does not matter Drive or Reverse. When I slow way down or stop it throttles down to about 200 RPMs and wants to die.

No check engine light, idles great in Park and Neutral, drives fine, no noticable problems.

Any ideas on what is causing to want to die would be great.
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Karstenss
May 23, 2007.



Few questions. Does you truck have dual tanks? Showing that fuse connected to the secondary fuel pump relay. CIrcuit also powers the. Intake Air Temp Sensor, Fuel Composition Sesnor(flex fuel), Evap Canister Purge Solenoid, and last but not least.1-2 shift solenoid, 2-3 shift solenoid, and 3-2 solenoid, TCC solenoid, TCC PWM Solenoid. Im suspecting a shorted solenoid in the trans since it is ok out of gear

Tiny
Jack42
May 23, 2007.
It has only one tank, and does not use Flex Fuel. I hooked up a Diag Scanner and it moted a problem with the CAT and the EVA. So now I am leaning toward an Emissions problem. But what system would not give me a check engine light? It does have a custom exhaust, and since I bought it used, I don't have specifics.

Tiny
Karstenss
May 24, 2007.
Exactly what P codes did it give you?

Tiny
Jack42
May 25, 2007.
The scanner we used did not give P codes.

That is the exact scanner we used. It has little round icons on the top of the screen that blink as the vehicle is running that diagnose live.

I changed the PCV valve this morning and it seemed to help until I was coming home, and the RPM's dropped way down again.

I am leaning toward there being something exhaust related. I have black stuff gathering around the exhaust ends. I think next week I am going to straight pipe the system.

Tiny
Karstenss
May 25, 2007.
If you remove the cats you will set several other codes. Try cleaning out around the butterfly in the throttle bore with carb spray and a rag.

Tiny
Jack42
May 25, 2007.
So I took it to the local dealership and had them do a full diagnostics on it. They said about the same thing as you. The Throttle Body was dirty. Then they went on to tell me that the Fuel Pressure was only 43psi and recommended a Fuel System cleaning, oh and a new Fuel Pump. A total of $1100. Needless to say, I changed the fuel filter, cleaned out the Throttle Body and ran a concentrated cycle of Fuel System Cleaner through. It is running great now. I lost the excellent fuel milage I was getting (Seriousely I was getting like 21MPG), but it is running strong.

Thanks for all of your help.

Tiny
Karstenss
Jun 5, 2007.
Dont be surprised if the fuel pump does go out soon. They will do that, run fine then all of the sudden, wont start.

Tiny
Jack42
Jun 5, 2007.