3f-e Intermittent throttle?/fuel? loss? (1 Viewer)

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Keep in mind that the +12 from the EFI relay passes through an additional 2 splice points and 1 connector before it gets to the COR. If the +12 to the COR is becoming intermittent, then replacing the EFI relay would have no effect.

intermittent problems like this are difficult at best to diagnose. I would suggest removing the relay box in the left kick and looking closely at relay contacts and associated wiring for the COR.
However, we're still shooting in the dark until this can be verified as a fuel delivery issue.
 
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intermittent problems like this are difficult at best to diagnose. I would suggest removing the relay box in the left kick and looking closely at relay contacts and associated wiring for the COR

Pulled the relay box and gave everything a good look. No loose connections or corrosion. Everything seems to look good.
 
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Just to satisfy my own stupid curiosity I opened up the old COR. The contacts had some corrosion on them but not a lot. Not sure if a little corrosion is enough to cause the problem. I'm gonna drive it for a few days with tools and a multimeter in it. If it dies, hopefully I'll be able to do some investigating.
 
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Well, drove it around for 300 miles without any problem. Then, while getting off the freeway, did it again. I’m trying to troubleshoot on the side of the road with no luck. Occasionally it will start, run for a minute then die again. I’m starting to think heat has something to do with it. It’s definitely getting fuel all the time so either I was wrong before, or this is a separate problem.
 
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Tested the the coil. Primary resistance starts at 1.5ohms and slowly drops to .8ohms and stays there (a little high?). Secondary resistance is 13.22 k-ohms.
Could that be it?
 
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Tested the the coil. Primary resistance starts at 1.5ohms and slowly drops to .8ohms and stays there (a little high?). Secondary resistance is 13.22 k-ohms.
Could that be it?
Consumer grade meters are not the best at measuring low resistance values. You should first touch the meter leads together and subtract that reading from the actual component you're trying to diagnose.
If your meter has a "zero" function, touch the 2 leads together and zero out the meter first.
 
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Consumer grade meters are not the best at measuring low resistance values. You should first touch the meter leads together and subtract that reading from the actual component you're trying to diagnose.
If your meter has a "zero" function, touch the 2 leads together and zero out the meter first.
Touching the leads together gives .4. So, that puts the primary resistance at .4 which is lower than the range in the fsm.
Unfortunately my meter doesn’t have a zero.
 
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Touching the leads together gives .4. So, that puts the primary resistance at .4 which is lower than the range in the fsm.
Unfortunately my meter doesn’t have a zero.
FSM specifies .41-.50
I would say that a reading of .4 from a not-so-accurate meter is fine.
 
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Started pulling plug wires to look at the distributor cap and the wire from the coil fell apart in my hand. Looks like it was hanging on by a thread.
 
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After finding that badly deteriorated wire I was very confident that I’d found my problem.
I was wrong. After replacing plugs, wires, cap and rotor I’m sitting on the side of the road with the same no start problem as before.
Still have a CEL with the key on, definitely getting fuel at the cold start injector. The only thing I can find at this point is that the EFI relay was very hot. I swapped in a spare and nothing changed. It’s started a few times and managed to drive down the road 50 yards a couple of times but it dies again. I really think heat is an important part of the issue. It seems to be happening exclusively when it’s 100+ degrees outside.
 
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How is it possible that I’ve had this thing for 7 years and didn’t know that overheating wiring associated with the efi fuse and relay is a common problem?
I’m stupid.
 
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I don’t have any more time to mess with it. Starting tomorrow I’ll be working 84 hours a week for the next couple of months. I think she’s gonna get parked for a while.:(
 
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I finally got back to it this morning. Opened up the fuse block to look at the wiring. There appears to be some discoloration on the efi relay wiring(Y/R wire)
ABAA8CFF-F07D-4BC9-A4E2-EBB8C20241CA.jpeg

I’m not sure if it’s from heat or age or even if it’s deteriorated enough to cause my problem. I can’t get out of my head how hot the relay was last time it drove it.
 
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So, more reading lots of threads here and staring at the wiring diagram. I think I've allowed a hot relay to distract me. When it died on the road back in October, the CEL was on with the key in the ON position. If I'm understanding correctly, that means I do not have an EFI problem.
Is my current understanding correct?
 

red66toy

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Have you checked the fusible link connections? Those can get nasty, loose and corroded. Fuel pressure was checked already?
 

ppc

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So, more reading lots of threads here and staring at the wiring diagram. I think I've allowed a hot relay to distract me. When it died on the road back in October, the CEL was on with the key in the ON position. If I'm understanding correctly, that means I do not have an EFI problem.
Is my current understanding correct?

The CEL on with the key on means the ECM is powered on, nothing else.
 

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