Runs crappy cold, OK when warm
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Senior Member
Joined: Nov 2001
Posts: 870
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From: Savannah, GA
Car: 3
Engine: inboard
Transmission: underfloor
Runs crappy cold, OK when warm
Our '91 3.1 has been acting up for a while.
When you start it up cold, it has a definite misfire on one or more cylinders and bucks and pops for the first 5 minutes on the road, then it's ok- idles a bit rough- fuel mileage is way off at 22-23 rather than the 26-28 it used to get.
The last time it was doing this, I opened the hood at night to see my coil wire was arcing against a plug wire, I installed a new Accel coil wire I had as a spare- no change- except it now will arc against a VACCUM hose to the MAP sensor.
Taking this one step at a time- I had aquired a spare distributor from a Pick-Your Part some time back- so I rebuilt it will all AC Delco components- pickup coil, module, rotor and cap. I installed it, and set the timing to 10 degrees BTDC with the EST wire or whatever you call it unhooked. It did sputter a bit at idle when I first started it, then smoothed out. I reconnected the wire and took her around the block, seemed good. I may add the old distribtor was so cruddy inside with rust on the poles of the pickup and fuzzy white corrosion on the cap terminals that I can't understand HOW it ran at all!
BUT- listening to it at idle, I could hear a "SNAP!" sound periodically- the coil wire was arcing out between the coil bracket from time to time. I moved the wire a tad and it stopped, but still makes no sense. I don't really think it's the wire as it's done the same thing with two different ones.
ANyway, the drive around the block was fine. Got in it 1 hour later, go for a drive and it's popping, missing and hesitating all the way to the store and back (mile and a half, each way)
I am perplexed as to the coil wire's arcing out. If it runs ok warm and crappy cold, this leads me to believe it's either a heat related ingnition problem OR something else that only acts up in open-loop, or delays the car going into open loop.
I have not checked the fuel pressure yet, not have I checked codes.
I wish I had some software to scan this thing or datalog it to see what it's doing.
Can anyone shed some light on this thing for me? All I have eliminated so far is the distributor and it's internals were "NOT IT"
Eric
When you start it up cold, it has a definite misfire on one or more cylinders and bucks and pops for the first 5 minutes on the road, then it's ok- idles a bit rough- fuel mileage is way off at 22-23 rather than the 26-28 it used to get.
The last time it was doing this, I opened the hood at night to see my coil wire was arcing against a plug wire, I installed a new Accel coil wire I had as a spare- no change- except it now will arc against a VACCUM hose to the MAP sensor.
Taking this one step at a time- I had aquired a spare distributor from a Pick-Your Part some time back- so I rebuilt it will all AC Delco components- pickup coil, module, rotor and cap. I installed it, and set the timing to 10 degrees BTDC with the EST wire or whatever you call it unhooked. It did sputter a bit at idle when I first started it, then smoothed out. I reconnected the wire and took her around the block, seemed good. I may add the old distribtor was so cruddy inside with rust on the poles of the pickup and fuzzy white corrosion on the cap terminals that I can't understand HOW it ran at all!
BUT- listening to it at idle, I could hear a "SNAP!" sound periodically- the coil wire was arcing out between the coil bracket from time to time. I moved the wire a tad and it stopped, but still makes no sense. I don't really think it's the wire as it's done the same thing with two different ones.
ANyway, the drive around the block was fine. Got in it 1 hour later, go for a drive and it's popping, missing and hesitating all the way to the store and back (mile and a half, each way)
I am perplexed as to the coil wire's arcing out. If it runs ok warm and crappy cold, this leads me to believe it's either a heat related ingnition problem OR something else that only acts up in open-loop, or delays the car going into open loop.
I have not checked the fuel pressure yet, not have I checked codes.
I wish I had some software to scan this thing or datalog it to see what it's doing.
Can anyone shed some light on this thing for me? All I have eliminated so far is the distributor and it's internals were "NOT IT"
Eric
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