http://www.j-body.org/forums/read.php?f=11&i=128405&t=128405
Heres the link to where I posted the original topic........since I don't know how many people w/ 2nd GENS visit that forum I decided to post it here with the hopes of hittin the target audience and gettin a better response....this has got me stumped........been about 5days workin on it (NOT the whole day) and nothin yet. Feel free to either post a response here or at the above link
THANKS
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Been awhile since I've posted 2 any Z site but I've gotta problem that has me STUMPED!!
1991 Z-24 3.1 V6 5spd
Crank pulley, Down Pipe, HI Flow Cat, Full Exhaust
FastChip installed
Run 91-93 Octane
130,000 Original Miles
When I was getting on the highway last week very fast thru a corner my car ended up dieing on me, felt almost as if the throttle cable had snapped in that the gas pedal had no effect on the engine RPM whatsoever. Figured I may have run out of gas since I was goin 2 get gas and had about 2.5 gallons left, friend got me gas so I was able to get 1 gallon into it but nothing, after awhile the car started would idle but any time I blipped the throttle it would die.
Car was towed home.
Some Symptoms I've noticed
- Next day car started fine but blipping the throttle would cause it to die but I was still able to get it into our garage and onto the lift.
- You can start the car whenever the engine is cool or cold but when it is warm or has already stalled out not always able to start it right away.
- The car will sometimes be idleing fine but then without warning, just die.
- If you press the gas to the floor it will increase in RPM by about 1000 drop 1000-2000 (depending on the rpm you started at) and increase again by 1000 drop the same amount and then go up by the same amount, repeating itself untill it stalls or you let off the gas.
- Blipping the throttle still causes it to want to die or to die and it sounds like the car is gasping for air.
- Only when the car is off and the ignition in the ON position, the Check Gages (NOT CHECK ENGINE) light illuminates, will go off, come on, go off, and come on, and sometimes stay on but the gages read normal
- I've smelt unburnt fuel from the exhaust for a few years now but have alwasy passed emmisions and only smells at startup (running a FastChip Chip)
- For the past 2.0 months the idle at startup has been kindof ruff as in when you step on the gas it does not have a smooth sound but would clear after a minute or so to the point where it sounded normal
What I have checked and what has been replaced
I've used an AutoXray ScanTool for GM Vehicles set up to scan the 91 Z24
Fuel Pressure - OK
Fuel Pump - New, less than 6000mi
Fuel Filter - New, installed today, 0mi
Fuel - added 2.5 Gallons of 93 Octane
Fuel - added STP Fuel INJ Cleaner
Air filter, 10" K&N Cone filter, Cleaned, less than 2000
NO Obstructions in air intake or TB
PCV Valves removed 7 years ago, No Problems
ECM - Checked with known Good
Mem Cal - Checked with known Good
CPS (Crank Pos Sen) - Checked with known Good
MAP Sensor - Checked with Known Good
MAP Hose OK and when disconnect will set code.
Ignition Module checked with known Good
Coils Tested and alll 3 are within SPEC
New Plugs and Wires less than 2000mi
TB was cleaned and regasketed less than 2000mi
IAC Motor checked with known good
All vacum lines from TB were checked for cracks, still need 2 look at the ones going to the charcol canister
Cleaned TB with STP TB Cleaner
TPS registers proper voltage and shows correct throttle angle %
CTS and IAT temperature readings when compared are within limits
O2 Sensor, NEW-adjs itself accordingly when engine is running.
SO WHAT IS IT?
I will not rule out ignition or fueling problems, could it still be the pump even though its a new BOSCH?
ANY IDEAS or what I can check next would be greatly appreciated, I know someone has delt with this before,
Thanks every1 for your help and ideas
- PETE
<img src = "http://registry.gmenthusiast.com/images/91cavaliergtrz/personal_pic.jpg"> Don't Bother The Emblem IS GONE!!!
