Well a few months back I picked up a 93 GMC 1500 2 wheel drive rez truck from a friend. 370,600km on the clock and V8. Its got a few problems but otherwise is a decent truck for what I need it for. I replaced the brake switch and got the TCC locking up again but have to chase a low speed surge/stumbling problem. The hose that routes the PCV to the throttle body was rotten so I have that plugged for now. But the main issue is this: once the engine is up to temp it stumbles from idle until around 1500rpm and then it levels out and drives fine on the highway and pulls great through the rev range. It idles fine but once you tip in that is where it stumbles. It never dies.
When it is cold it starts and runs fine. Because of this I was thinking oxygen sensor first. Thinking closed/open loop operation.
Any thoughts?
Thanks!
When it is cold it starts and runs fine. Because of this I was thinking oxygen sensor first. Thinking closed/open loop operation.
Any thoughts?
Thanks!