I have a 2003 cargo van with a 318. Sometimes the engine will have a ignition miss and backfire then smooth out and be fine. Now it quits while driving especially when the a\c is on. after letting it sit for about 20 min. I hear a loud click from under the dash and it starts up and runs fine. I tried another ECM from another idenical van today and it still backfired after driving for about 30 min, so I think the computer is good. I also put a new ignition coil in. About 2 months ago I had a code that said shorted o2 sensor, could that shut down the engine? The only other codes I hade where multiple engine misfires.Thanks in advance for any advice, Dan

 

Yes it could. The heating element in the O2 sensor shares power with the ignition. So a short within the O2 sensor would drop the ignition voltage and kill the engine.

 

Thanks again alloro, You have helped me with several problems in the past on this van. Tonite I took it out for a drive hoping to get a new code. After about 5 miles the engine stopped suddenly but not completly stalling, and the gas gage went from 1\2 full to empty.The engine immediatly started running ok and and after about 3 min the gage gage jumped up to 1\2 full again. Still no codes showing. Once tonite I was pushing on the connectors on the ECM and the engine stalled, I dont know if I caused this, but im wondering if a bad connector on the ECM could cause all of these problems? I could not get it to stall again. Thanks Again, Dan

 

Yes a bad connection to the PCM could cause all of these problems. The odds of it stalling just as you pressed on the connector and it not being related would be astronomical.

 

In my experience the ECM / PCM modules on these vehicles become increasingly sensitive to temperature extremes when they are beginning to go completely belly-up.

On my 93 B150 I had two (2) complete PCM failures. The first one was in the winter when temps were consistently in the 20's. I could start the van by warming the PCM thru the vent holes with a hair dryer for a few minutes.

The second PCM failure was in the summer - same exact thing in reverse. When the temps were in the 80's (underhood temps easily 100+) I could start my van by cooling the PCM with some cold water poured thru the plastic case vents. The PCM is completely waterproof inside, so there was no danger of shorting the thing out. Well, very little danger anyway.

For what it's worth.

 

I'm in a touring band. look at my user name, thats what we have as far as van in concerned, lol.

anyway, ours does something similar. On the highway, its fine. But slowing into traffic, itll just die sometime. after letting it sit for a while (30-40 min) it starts just fine. rarely we have to use a little starting spray. But it ONLY does this when its really hot out, never in the spring / fall / winter. Totally confused.

I know some car stuff, please help - we have a tour soon!

 

I removed this message and reposted it in another thread.
So move along, nothing to see here.

 

Can you tell me what you found to fix this? I have an almost identical problem. I hear a click in the dash (like a relay) and everything cuts out, if the engine is at a reasonable RPM it restarts by itself but if you are idling at a stoplight it quits. The gas guage changes every other click from whats in the tank to empty. Was it the O2 sensor?

TIA