Hi guys-

My 1992 400SE is running like crap all of sudden that it is hot (as in over 100). Anytime it hits 100 my car runs like crap. It bascily is missing on several cylinders.

I checked fuel pressure today and have 45 lbs while the car is running.

I pulled one of the ignition wires off of the cap with my ignition pliers on the right side bank and noticed that the coil is strong, (good arc) but when I disonnected the wire from the cap I got a DEAD miss, normal.

I did the same to the left side, and after I removed the wire from the cap, the terminal on the distributer cap began to arch fiercly against the side of the cap WITH THE WIRE REMOVED! but I got no change in the way the car runs.

This must be a sign of a bad cap on the drivers side? but why does it only miss when its hot? These caps are only a few years old.

Do you agree with my diagnosis?

Thanks in advance for the input!


Kyle

 

Hmmm, now the other cap does the same thing as far as arching with the ignition lead pulled. it has cooled down to about 90 and now the car is running fine. What is going on? My harness is not in great shape, but my understanding is that I would have a check engine light if it were really bad and effecting the output of any sensors.

I am not convinced that either cap is bad, maybe a temp sensor? or an intake air temp sensor?

can someone post the values for these two sensors so I can be sure neither is way out of whack?

With no live data it will be difficult to test the AFM.

 

Both sensors are very close to actual values, with 10 degrees.

but the ambient temp has cooled to 78 and the car runs like a champ! Why only in the heat does it run this way?


Kyle