Colorado2500
I'm Awesome
Truck has had a rough idle for a while now, but other than that, it ran well.
Recently, it begin to idle so poorly that it would barely run and would stall. Diagnosed as a bad EGR valve, valve was stuck open with bits of something. Replaced EGR valve & solenoid as well for peace of mind.
After those, it starts (after random starter failure between there), and runs but the idle is erratic, and stills runs rough but could be driven and hasn't stalled since. I've narrowed the issue to jumpy timing, with the tan/black wire disconnected it idles between 0 degrees and about 4 degrees retarded but is all over in there. I noticed it sounds normal when it jumps to 0 degrees (makes sense). Only pulling ~15" of vac at idle.
MAP and coolant temp sensor check out.
Harris at tbichips.com says on his tbi troubleshooting page jumpy timing is likely a bad pickup coil or magnetic reluctor ring. Under my cap, stuff looks a bit corroded, should I just go ahead and replace those two parts?
Unsure how to proceed, I can't find anything to test either component. Any advice is greatly appreciated.
Edit: other notes: no vac leaks, idle condition much more pronounced when engine is warm/hot.
Recently, it begin to idle so poorly that it would barely run and would stall. Diagnosed as a bad EGR valve, valve was stuck open with bits of something. Replaced EGR valve & solenoid as well for peace of mind.
After those, it starts (after random starter failure between there), and runs but the idle is erratic, and stills runs rough but could be driven and hasn't stalled since. I've narrowed the issue to jumpy timing, with the tan/black wire disconnected it idles between 0 degrees and about 4 degrees retarded but is all over in there. I noticed it sounds normal when it jumps to 0 degrees (makes sense). Only pulling ~15" of vac at idle.
MAP and coolant temp sensor check out.
Harris at tbichips.com says on his tbi troubleshooting page jumpy timing is likely a bad pickup coil or magnetic reluctor ring. Under my cap, stuff looks a bit corroded, should I just go ahead and replace those two parts?
Unsure how to proceed, I can't find anything to test either component. Any advice is greatly appreciated.
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Edit: other notes: no vac leaks, idle condition much more pronounced when engine is warm/hot.