95 Lumina APV

[Raff]

i have a 95 Lumina APV and i just replaced the spark plugs with AC Delco R43TS spark plugs are they right? reason im asking is because my van runs really bad now with hesitation and light backfiring and i replaced the ignition leads one at a time as not to get them wrong. Any help is much apprecited.

[cadgear]

Did you gap them correctly? Reconnect everything you may've disconnected when you replaced them? In my lumina sedan you have to rotate the engine forward and I had to remove the alternator, and when I put it all back together I forgot to put the serpentine belt back on :P Of course, it may be a vacuum line or something small like that.

[Raff]

ok guys i have got more on the problem....i have figured that the plugs are correct. I think what the problem is .....the Temp sending unit on the head is bad and the computer thinks the engine is hot...but of course it isnt...so the its tellin the carb to pump more fuel into the cylinders for cooling.That would explain the flutter and the burning smell and the backfiring.Gonna replace that next.Will keep you updated.If you guys have any thoughts..please feel free to share.

[300+]

I am interested in the answer. I have a 95 APV with the 3.1 and it just started doing the same thing. Seems to only do it after it warms up, then more frequent and severe under load. I had replaced 3 front plugs a while ago and got around to doing the back 3. No change. New coil and coil wire due to corrosion, but no change. New fuel filter recently as well. Has 175,000 miles.

[altij]

I have same problem someone told change tps and still doin same thing,now they tell me is map sensor,also did tune up,mine is also a 95 3.1 with 110,000 dont have backfiring.

[300+]

I changed the thermostat and oxygen sensor last night and took it to work today. Seemed OK. The temperatue is holding much better now.
I checked my Throttle Position Sensor and it was OK.
Test was not correct in manual for 3.1. I did it like the 3800 terminal using terminal C instead of A&B. Picture also didn't match.
For anyone doing the 02 sensor. You can get a 3/8" swivel and 6 " extension to a breaker bar and pipe up through the top. Note it requires o2 socket.
Just remove the air cleaner.
Allows much better control of the force you apply.
I will update if problems come back.
Thermostat was good one ~$8
Bosch 02 ~$20. at Advance Auto
MAP I think unlikely since mine was the same when disconnected. It goes into an open loop using defaults. Give that a try. Green connector on front of air cleaner. Will get check engine light which can be reset afterwards by taking off bat.