So here is the story, (1988 turbo auto car, 115k miles) car ran great for first couple thousand miles of ownership (aside from speedo cable breaking and heater vsv quitting) and one sunday morning I fired it up and noticed a misfire.
The characteristics of the misifire are a stumbly idle (with motor shakes) and very very poor acceleration up until boost and some occasional dying at idle when warm after coming down from speed. The miss is not affected by temp or run time, it just dissapears under boost, atleast for the most part.
Here is what I have done so far. Checked plugs (looked fine), checked resistance on plug wires (some deviation but nothing out of spec), checked for anything obvious like vacuum leaks or bad wire connections (car would have an occasional no start from bad connection in cps connector but has been fixed.
Now here is the interesting part, checked the engine codes and a 12 came up. So I checked cps and one of the coils was dead (ge1 i think) so I got a used cps, resistance was off but not too much, all cicuits functioned, and same problem. One more cps later, same problem. And since either of the newer cps have been in, no code 12.
Would a dead ge1 coil cause this sort of drivability issue and if so, why would it persist after cps replacement? I thought to check continuity between wires from cps connector to ecm but how do I get to the ecm and will these wires be same color as they are coming out of the cps connector? Anything else to check? Thanks, hope I didnt make this too long.
edit: also if i pull off any of the plug wires individually, it almost kills it so it would seem its not caused by one cylinder not firing or firing poorly and I obviously have timing properly set at 10 btdc
The characteristics of the misifire are a stumbly idle (with motor shakes) and very very poor acceleration up until boost and some occasional dying at idle when warm after coming down from speed. The miss is not affected by temp or run time, it just dissapears under boost, atleast for the most part.
Here is what I have done so far. Checked plugs (looked fine), checked resistance on plug wires (some deviation but nothing out of spec), checked for anything obvious like vacuum leaks or bad wire connections (car would have an occasional no start from bad connection in cps connector but has been fixed.
Now here is the interesting part, checked the engine codes and a 12 came up. So I checked cps and one of the coils was dead (ge1 i think) so I got a used cps, resistance was off but not too much, all cicuits functioned, and same problem. One more cps later, same problem. And since either of the newer cps have been in, no code 12.
Would a dead ge1 coil cause this sort of drivability issue and if so, why would it persist after cps replacement? I thought to check continuity between wires from cps connector to ecm but how do I get to the ecm and will these wires be same color as they are coming out of the cps connector? Anything else to check? Thanks, hope I didnt make this too long.
edit: also if i pull off any of the plug wires individually, it almost kills it so it would seem its not caused by one cylinder not firing or firing poorly and I obviously have timing properly set at 10 btdc
