Crappy running 85 GMC.

[HotRodPC]

The coil is new from the TSP dizzy you got from Clean right??? Cuz a coil can create this problem you are having. It works fine, then once it gets hot, it starts losing it power and will cause hesitation. Maybe for **** and giggles put in your old coil and see what happens. Also, make sure you don't have any vacuum leaks at the intake.

 

[Irishman999]

The coil is new from the TSP dizzy you got from Clean right??? Cuz a coil can create this problem you are having. It works fine, then once it gets hot, it starts losing it power and will cause hesitation. Maybe for **** and giggles put in your old coil and see what happens. Also, make sure you don't have any vacuum leaks at the intake.

Its not the coil, I had the same problem with the old distributor. I guess its time to get a vacuum gauge.

 

[Old77]

This is probably a stupid question but can a new coil be defective??

 

[HotRodPC]

Very Very Very rare, but yes. Its also very rare one of these coils goes bad. But, he has emiminated that as the problem since he's had 2 differant coils on it and the problem is unchanged. Now he knows its not the carb either.

Do yourself a favor Imann, if you have a voltmeter, check your voltage to the dizzy hot wire. Check it with Key on motor NOT running, and check it with motor running.

 

[89Suburban]

The coil is new from the TSP dizzy you got from Clean right??? Cuz a coil can create this problem you are having. It works fine, then once it gets hot, it starts losing it power and will cause hesitation. Maybe for **** and giggles put in your old coil and see what happens. Also, make sure you don't have any vacuum leaks at the intake.

ABsoloutely right about a hot coil acting up, like something inside expands and looses a connectione or something, like maybe an internal winding. I have dealt with that in the past. Then once it cools down it runs fine. So if you test it while it's cold it will show it's fine. I even had that problem with my last boat motor coil. Sumbitch ran on once cylinder til it got hot then it ran fine on 2 cyl after warm up.

Here on the coil under the flywheel, there was a fine hairline crack in that hardnened gel **** they use to seal a circuit. You could barely see it and it made all the difference in the world what temp that circuit had to heat to to close that gap and make the connection and run. If somebody didn't menton to me on a forum to check the coil both hot and cold while testing, I would never had found that. Just something to keep in mind.

 

[89Suburban]

This is probably a stupid question but can a new coil be defective??

You see the retards working behind most of today's parts counters, anything could be possible dude.

 

[Old77]

I know this is a pain in the ass for Iman but in the end when the problem is solved we will have some great info in this thread

 

[Irishman999]

I just thought of something this morning, what if the timing chain is stretched? Yesterday I let the truck sit and idle for a while, I drove it around the parking lot and mashed on the metal, it did not speed up but back fired out of the exhaust instead...... Im going to get a vacuum guage in a little bit and after that start pulling out plugs for inspection.

 

[89Suburban]

I just thought of something this morning, what if the timing chain is stretched? Yesterday I let the truck sit and idle for a while, I drove it around the parking lot and mashed on the metal, it did not speed up but back fired out of the exhaust instead...... Im going to get a vacuum guage in a little bit and after that start pulling out plugs for inspection.

Yah, throw a vacuum guage on the manifold and see what that says. Is this a stock motor or is is camed up?

 

[Irishman999]

Yah, throw a vacuum guage on the manifold and see what that says. Is this a stock motor or is is camed up?

Stock cam, everything basically stock.

 

[89Suburban]

Is that an HEI dizzy then?

 

[Swims350]

well let me see, have you switched the hei vac. line to the other side? one's ported or timed the other is full vac.

Have you tried the adjustable vac. can on the dist. like tighten or loosen the screw in it?

Have you tried to give it more base timing or less?

 

[89Suburban]

well let me see, have you switched the hei vac. line to the other side? one's ported or timed the other is full vac.

Have you tried the adjustable vac. can on the dist. like tighten or loosen the screw in it?

Have you tried to give it more base timing or less?

 

[Swims350]

man do you love popcorn lol.

 

[Old77]

man do you love popcorn lol.

His favorite is Pop Secret!!

I think that instead of putting "popcorn" between the colons (":") we should just make it to where you type :89Sub: in there and the popcorn comes up