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Discussion Starter · #21 ·
Tomorrow turned out to be this morning. Got the salt and pepper connectors all cleaned out, used spray terminal cleaner, a tiny Q-Tip from a hobby store to clean out the female terminals, spread the male terminals slightly with a pick, applied dielectric grease to all connections. So far, no change, still rough running/miss when cold. But at least that's one more thing crossed off the list.
 

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Discussion Starter · #22 ·
Fixed it. Runs mint, never better. Any guesses as to what it was? The symptoms were stalling once on cold start, rough running/hesitation until warm, idle higher than usual, idle speed would occasionally drop 100-150 RPM in drive at a light, poor fuel economy - down 1.5-2 MPG.
 

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Just throwing out a random guess


Vac leak?


Sent from my iPhone using Tapatalk
 

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Discussion Starter · #24 ·
Very astute guess.


No code for this problem, just good old-fashioned diagnostic skills/hunches. Was the smoke tester my idea because I'm such a prodigy? No, it came from watching Youtube videos of pro mechanics using them. For anyone considering a smoke test machine, the problem was solved in minutes.

Thanks to everyone for the suggestions, all were helpful, and it's not a bad idea to replace certain 30+ year old sensors on these cars if they are suspect. This car had a raft of problems; the PIP sensor, the vacuum leak, the burnt ignition switch, and a few questionable plugs and connectors here and there. Interestingly, the original date coded plug wires were not a problem, but the new set will stay.

Sorry for the vertical video, this is my first time ever posting a video on Youtube.
 

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Very astute guess.

Lets just say it's not the first time i've seen a poorly running car go through all the electrical and sensor checks and not show anything wrong, end up being a vac leak from a poorly sealed lower intake manifold.


Glad you found it
 
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Very astute guess.


No code for this problem, just good old-fashioned diagnostic skills/hunches. Was the smoke tester my idea because I'm such a prodigy? No, it came from watching Youtube videos of pro mechanics using them. For anyone considering a smoke test machine, the problem was solved in minutes.

Thanks to everyone for the suggestions, all were helpful, and it's not a bad idea to replace certain 30+ year old sensors on these cars if they are suspect. This car had a raft of problems; the PIP sensor, the vacuum leak, the burnt ignition switch, and a few questionable plugs and connectors here and there. Interestingly, the original date coded plug wires were not a problem, but the new set will stay.

Sorry for the vertical video, this is my first time ever posting a video on Youtube.
It all comes down to having the right tool for the job.

My 91 too was still running strongly on the original 1991 plug wires until I decided to change them in 2019 when I installed a Vortech.

Glad you figured it out.
 
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Those smoke machines look like a worthwhile investment, saw one on Ebay for $80, might have to grab one.
 
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