no codes but 111

[tommyturbo]

Had a odd experience tonight. 95 MTX 176K. Was in city streets at low speed, felt like compressor cycled (climate was on) and on my car I have noticed when the compressor cycles sometimes temp gauge moves a bit quickly ( like a blip). Anyhow felt like compressor cycled, gauge blipped, then started misfiring badly while driving, check engine light came on. Seemed to idle semi ok. Drove short distance to target parking lot, misfired pretty bad under load to there. Popped hood, the made sure all plug wires seated at cylinders and at coil pack. Left engine running whole time. Cel went out and seemed to stop misfiring. Restarted normally, cel did not come back on. Drove 20 minutes home on fwy, ran completely normal. Ran KOEO and KOER test with scanner and only get 111. To be clear I have a scanner that will work with ford obd 1 and I've used in many times, under memoery codes just get 111.

I would think there should be some code in mem at least since it obviously detected a problem and came on. I was concerned maybe a dis issue and crank sensor maybe ( but when those have happened to me before lost tach or car just died completely). Should I be concerned the computer is being funny since it had no codes or look at my wires ( denso, but they seem to not be best I have seen). Open to thoughts...

 

[luigisho]

I would be concerned with a CEL and no codes. Are the wires in bad shape? 30yr old cars everything is suspect. Do you happen to carry a spare pcm? I usually tried to have a spare pcm, ccrm, and crank sensor for those oh s*it moments

 

[SHOdded]

yeah, CEL and no codes usually means bad ecm especially if you piggybacked a mod onto it.

 

[tommyturbo]

The plugs and wires were done in 2019, and have maybe 10 to 15 k on them at most. But the one wire going to cylinder 4 has never fit as flush, and seems to like to lift up and make a obvious gap at valve cover. Push it back down every so often.

Computer is stock, have never messed with it or done any mods to it. Have had this car since 2006 and do not think anyone messed with it before.

I've had computer issues on my others over the years, usually with a particular code that just keeps recurring or in the case of my 89 it just started throwing out jibberish codes and running bad. On my atx it was a reoccurring code for the egr flow.

Otherwise car has ran fantastic up to this.

 

[luigisho]

I've seen pcm failure do all sorts of things but not having/storing codes is a somewhat more common symptom. Not saying this is the issue but it is an eyebrow raise to consider it. Again I would, and have, had a spare (or 2) on a shelf over the last 25+ yrs to make quick work of ruling out computer fault issues.

 

[FastCAD]

Had a odd experience tonight. 95 MTX 176K. Was in city streets at low speed, felt like compressor cycled (climate was on) and on my car I have noticed when the compressor cycles sometimes temp gauge moves a bit quickly ( like a blip). Anyhow felt like compressor cycled, gauge blipped, then started misfiring badly while driving, check engine light came on. Seemed to idle semi ok. Drove short distance to target parking lot, misfired pretty bad under load to there. Popped hood, the made sure all plug wires seated at cylinders and at coil pack. Left engine running whole time. Cel went out and seemed to stop misfiring. Restarted normally, cel did not come back on. Drove 20 minutes home on fwy, ran completely normal. Ran KOEO and KOER test with scanner and only get 111. To be clear I have a scanner that will work with ford obd 1 and I've used in many times, under memoery codes just get 111.

I would think there should be some code in mem at least since it obviously detected a problem and came on. I was concerned maybe a dis issue and crank sensor maybe ( but when those have happened to me before lost tach or car just died completely). Should I be concerned the computer is being funny since it had no codes or look at my wires ( denso, but they seem to not be best I have seen). Open to thoughts...

It is best to have a spare (good) pcm, it quickly can tell you if the old one has a problem, if so just leave it in and get a backup. That said, try the paper clip method to run the codes and read the cel light. I have found that the paper clip method does not fail, but the OBD1 is unreliable sometimes, so give it a try first before you fall into a rabbit hole.
best to ya.