95 S10 4.3 CMPI Stalling / Hesitation
StolenRedCamaro
08-05-2008, 08:32 AM
Ive been having problems with my 95 S10 blazer stalling (4.3 multi port injection, W Vin code), ive searched on here and read through others similar problems but the catch is mine only does this when its warmed up
Symptoms & Behavior:
For the past month the truck has ran fine when cold. Soon after it hits operating temp, while driving it has some hesitation under constant throttle, like a misfire. However when accelerating all is fine and it has plenty of power. More recently its been stalling on me when i come to a stop, so ive been been holding the idle up while stopped and it stays running, although i hate doing this i dont want to kill the converter. Its worsened to the point where once stalled it usually wont start again until cooled off. I smelled a
ton of gas while i tried to keep starting it to the point where i saw raw gas dripping out the tailpipe.
What I did/fixed so far:
Here i thought fuel, so i pulled the manifold and unplugged the 6 poppet valves for the fuel injection so i can watch them, i turned the key on and fuel was pissing out of all 6 full stream - that would explain the gas out the exhaust. The plugs were soaked with gas too... so i bought the new spider injection ($360 later), tested that the same way, key on and no fuel out the poppet valves, so i put everything back together with new plugs and oil change, started right up and ran perfect... now thinking it was fixed, i let it warm up and took it for a drive and the hesitation problem still persists, the exact same symptoms i said before. Annoyed, i troubleshooted the rest of the fuel system, replaced the fuel filter, hooked up a fuel pressure gauge, propped it outside the hood and drove it - and it held good pressure (~57-65) the entire time, even while it stalled it still held pressure.
Quick video i made showing the problems:
http://www.youtube.com/watch?v=3mo0c2n9jfs
So now im either thinking ignition or a sensor thats getting aggravated with temperature?
Symptoms & Behavior:
For the past month the truck has ran fine when cold. Soon after it hits operating temp, while driving it has some hesitation under constant throttle, like a misfire. However when accelerating all is fine and it has plenty of power. More recently its been stalling on me when i come to a stop, so ive been been holding the idle up while stopped and it stays running, although i hate doing this i dont want to kill the converter. Its worsened to the point where once stalled it usually wont start again until cooled off. I smelled a
ton of gas while i tried to keep starting it to the point where i saw raw gas dripping out the tailpipe.
What I did/fixed so far:
Here i thought fuel, so i pulled the manifold and unplugged the 6 poppet valves for the fuel injection so i can watch them, i turned the key on and fuel was pissing out of all 6 full stream - that would explain the gas out the exhaust. The plugs were soaked with gas too... so i bought the new spider injection ($360 later), tested that the same way, key on and no fuel out the poppet valves, so i put everything back together with new plugs and oil change, started right up and ran perfect... now thinking it was fixed, i let it warm up and took it for a drive and the hesitation problem still persists, the exact same symptoms i said before. Annoyed, i troubleshooted the rest of the fuel system, replaced the fuel filter, hooked up a fuel pressure gauge, propped it outside the hood and drove it - and it held good pressure (~57-65) the entire time, even while it stalled it still held pressure.
Quick video i made showing the problems:
http://www.youtube.com/watch?v=3mo0c2n9jfs
So now im either thinking ignition or a sensor thats getting aggravated with temperature?
MT-2500
08-07-2008, 09:12 AM
If the fuel pressure is holding good.
Check he secandary ign system.
Good plugs wires and cap and rotor.
Good hot blue spark and ign timing.
Good engine vacuum?
Check the computer data and sensors and for codes.
Post back any codes.
MT
Check he secandary ign system.
Good plugs wires and cap and rotor.
Good hot blue spark and ign timing.
Good engine vacuum?
Check the computer data and sensors and for codes.
Post back any codes.
MT
Automotive Network, Inc., Copyright ©2025