‘95 K1500. I wish I had access to an OBD-1 scanner but I do not.
As you may remember I bought this truck about a month ago after it had sat for twelve years. 119k miles. It was parked because it had no power on acceleration. And it still does not. It idles smoothly but stumbles like crazy when trying to get up to speed. I can get it up to freeway speeds and it runs smoothly with or without cruise control, but just has issues accelerating at any speed.
A new battery, fuel pump, and fuel filter got it running. I’ve discovered that the poor performance only manifests itself once the engine has been running for at least 20 to 30 minutes. So I figure it’s not so much of a closed-loop issue as it is a heat-soak issue.
Luckily these engines have very few components on them so I figure that, with the mileage on the truck and considering how long it sat idle, nothing I replace will be money wasted.
I’ve changed plugs, wires, cap, and rotor. No change, although all were in desperate need of replacement. Surprisingly, the fuel injectors have a very nice spray pattern. No vacuum leaks that I can find.
Today I’m going to throw a new coil on it. If that doesn’t work I’ll try a new MAP sensor. Next up will be an oxygen sensor. The TPS SEEMS to be operating correctly even when it is running poorly, but if nothing else works I’ll try that too.
Anything I’m missing here? (Besides the obvious step of actually buying an OBD-1 scanner)
I have been working on cars for 50 years and this is the first time I’ve ever resorted to just throwing parts at one.
Any suggestions?
Thanks,
Tom.
As you may remember I bought this truck about a month ago after it had sat for twelve years. 119k miles. It was parked because it had no power on acceleration. And it still does not. It idles smoothly but stumbles like crazy when trying to get up to speed. I can get it up to freeway speeds and it runs smoothly with or without cruise control, but just has issues accelerating at any speed.
A new battery, fuel pump, and fuel filter got it running. I’ve discovered that the poor performance only manifests itself once the engine has been running for at least 20 to 30 minutes. So I figure it’s not so much of a closed-loop issue as it is a heat-soak issue.
Luckily these engines have very few components on them so I figure that, with the mileage on the truck and considering how long it sat idle, nothing I replace will be money wasted.
I’ve changed plugs, wires, cap, and rotor. No change, although all were in desperate need of replacement. Surprisingly, the fuel injectors have a very nice spray pattern. No vacuum leaks that I can find.
Today I’m going to throw a new coil on it. If that doesn’t work I’ll try a new MAP sensor. Next up will be an oxygen sensor. The TPS SEEMS to be operating correctly even when it is running poorly, but if nothing else works I’ll try that too.
Anything I’m missing here? (Besides the obvious step of actually buying an OBD-1 scanner)
I have been working on cars for 50 years and this is the first time I’ve ever resorted to just throwing parts at one.
Any suggestions?
Thanks,
Tom.
