sdryluth
Newbie
Hi there, I have a 1990 K1500 with the 5.7 TBI engine that i'm trying to diagnose.
Sometimes it will run just fine, especially when the engine isn't warm yet. When it's up to temp it will often go into this phase where it runs very rough and stalls. It especially likes to stall when coming to a stop, but in its rough running phase it will often get so bad that when I step on the gas the engine just sputters and doesn't do anything. Sometimes if I really try to fight it and keep the gas down when its misbehaving it seems to backfire with a loud bang from under the hood followed by a strong burnt oil smell.
When its in its happy, running nicely phase there is no check engine light on. When it starts to run poorly the check engine light will flash and/or come on and stay on.
The injectors were leaking quite a bit so I replaced them along with the pressure regulator diaphragm and also cleaned up the idle air control valve. This made no difference to the running issue at all.
The really weird thing is I can't seem to pull codes. I tried shorting the pins on the diag connector but the check engine light just stays on solid with key on engine off and refuses to start flashing to give me the codes. It won't even do the initial series of flashes to indicate that its in code checking mode.
Any ideas what I'm dealing with here?
Sometimes it will run just fine, especially when the engine isn't warm yet. When it's up to temp it will often go into this phase where it runs very rough and stalls. It especially likes to stall when coming to a stop, but in its rough running phase it will often get so bad that when I step on the gas the engine just sputters and doesn't do anything. Sometimes if I really try to fight it and keep the gas down when its misbehaving it seems to backfire with a loud bang from under the hood followed by a strong burnt oil smell.
When its in its happy, running nicely phase there is no check engine light on. When it starts to run poorly the check engine light will flash and/or come on and stay on.
The injectors were leaking quite a bit so I replaced them along with the pressure regulator diaphragm and also cleaned up the idle air control valve. This made no difference to the running issue at all.
The really weird thing is I can't seem to pull codes. I tried shorting the pins on the diag connector but the check engine light just stays on solid with key on engine off and refuses to start flashing to give me the codes. It won't even do the initial series of flashes to indicate that its in code checking mode.
Any ideas what I'm dealing with here?