Checking a '94 Touring for a buddy. Forgive me but I mostly deal with my FB..ya ya ya anyways I've been searching for about an hour and can't find the answer to my q. Please help and thanks in advance!!

Car cold starts ok but after 1 min both the trailing spark plugs stop firing. No check engine light that I know of. At this point should I check for codes? My process of elimination is its not the crank pos sensor since it still runs the leading fine. Its not the ECU since no check engine lights. Most likely wouldn't be BOTH the trailing coils. So that brings me to a failing/failed ignitor???

Suggestions? Comments? Slaps in the face??

 

wow...

 

check the resistor box under the cruise control.. its grounded to the body. also check continuity on the trailing plug wires and the coils

 

Could also be a bad ignition harness, they're known to go bad and do weird things.

Dale

 

check the coil harness, its been a while since ive had mine out, but I think that it only runs one ground to all three coils, and if that wire is in bad shape, it could be causing the problem. It sounds a lot like a wiring issue, and as im sure you know by now the worst part of those is finding where the problem is so you can spend a whopping 30 seconds to solder the thing back into place.

 

Sounds like a grounding issue on the ignition harness. You say it occurs about a minute after the engine is running, which suggests that heat soak is affecting the ground connection.

 

Check the distributor cap...

 

hahahaha......I knew I'd get that..

Really...grounding issue...hmm ok. Odd that if the one ground failed, the leadings wouldn't go down also. But I'll definitely look at it. Also the "resistor box" under the cruise control.... what would I be looking for there and what does it do? I know...newb q (slap)

 

Unless the wire is cut or unattached, you will have some ground. You have an imperfect ground and it is throwing the ECU an anomoly which results in no trailing spark.