[gixxersixxerman]

So I took my car out to run and pick up a new shop light for the garage. Drove to Walmart fine, drove to pick up Boba fine but when we left there, the car wouldn't start. Came up with warnings on the dash. Rapid clicking sound under the hood. I couldn't get anything to work. Then I popped the hood and the dash lit up properly and the car started. I open the hood and everything shut back off and went dark except the center screen. The relay was going crazy so I pulled out the book and seen it's a PCM relay, pulled a blower motor relay and swapped it and the car drove home fine. I figured I just had a faulty relay. The car has been problem free since I owned it besides a fuel pressure sensor on the fuel rail that I replaced about 3-4 weeks ago. Other wise it's been full stg3 and tune since 150 miles without issue running e30.

Once home I shut I off and restarted it to see if the hill assist disabled light would go out.. it did. I started it 3 more times and all is well. Then I opened my door and the flashers went off a few times. I tried to start and nothing. Relay going crazy so I record this video. I left it alone, installed the new shop light and picked up my son using our other car, and came home and everything started just fine on the ST. I have over half a tank of e30, so it's not like I can unpaid the AP and take it in.. working at Ford I know they will say it's from the mods or AP, when I know they would not cause any of this. Hopefully my Ford certs and ASE certs including electrical and electrical systems will help persuade them not to come up with that ignorant, the AP shorted out the PCM or some crap like that.

Anyway, here is the video, I'm wondering if it could be the harness TSB that I've read about, but I thought that was earlier model ST's not the new models

 

[gixxersixxerman]

Its been starting and not starting intermittently all day today.. Looks like the closest dealership is semi mod friendly and told me to take off the AP and bring it in.. i cant unmarry it as im e30 right now but he said its fine just toke it out and leave the rest alone.

 

[BlackT5]

If you un-marry and fill up you'll be E15ish. Reset the KAM and it will learn fine.

Sounds like a bad ground. Check one of the grounds below the air box, one of them is for the PCM.

 

[gixxersixxerman]

If you un-marry and fill up you'll be E15ish. Reset the KAM and it will learn fine.

Sounds like a bad ground. Check one of the grounds below the air box, one of them is for the PCM.

Winner winner chicken dinner.. I went out and pulled the filter off the injen intake and the grounding point closest to the fuse box, under the filter was loose.. tighten it and so far so good.. I checked the other ground at lunch and it was tight. Didn't realize/think to look for the other ground, even though I know there were 2

 

[BlackT5]

Just for good measure pull both off and clean the paint beneath them. Nothing beats providing the best grounds possible.

 

[hawkeye18]

IMO (backed up by 14 years of military avionics troubleshooting experience), grounding issues are the single most difficult problem, not only to repair but to diagnose in the first place. My sister has a late-oughts Civic that was having a devilish intermittent misfire issue. She'd taken it to her small-town mechanic no fewer than six times and he'd tried everything from rotating injectors and replacing spark plugs to running compression tests, etc. and every time he messed with it it'd be fine for a few days/weeks, then it'd start acting up again.

I finally convinced her to drive it down here (~9hr drive) so I could look at it. Opened the hood and the first thing I noticed that the block to frame ground wire was 8 gauge, pure green, fuzzy, and hanging on by no more than 10 strands. I replaced it, and the frame to battery ground wire (which was not in much better shape) with marine-grade 4-gauge wire and nice big ends, and not only did the cylinder 3 misfire go away but according to her like 10 other small weird problems with the car disappeared as well. Her mechanic never even thought to look at grounding at all.

It's a good thing you found the ground so easily! I always tell people, if the problem you're having makes you want, even jokingly, to call a priest, then it's probably a grounding issue. I've seen bad (or even partial) grounds cause some wacky-ass ****. I had a bad ground cause whatever was said on HF1 to modulate onto the radar pulse once, and it took us forever to figure out why we were getting such weird returns on the radar! It actually took the HF set to start having problems as well to catch it, because who the hell thinks to talk on HF1 while the radar is running on the ground?