Sputtering and Popping

[pontiacgp]

I've had an issue with the GP where with a light throttle it would run like it was missing, under acceleration it seemed ok. Let off on the gas the exhaust would pop and that is worse today than it has been. I put a new set of plugs and checked the timing, didn't help. I installed my spare distributor cap and rotor, din't help. The problem is getting worse and worse. I have a MSD 6A box which I don't think is a issue, they work or don't work. I have an MSD E curve distributor but working off the box it doesn't do much. I'm thinking it's the coil, it's the MSD Blaster SS that's about 3 or 4 years old. I cannot find my multimeter to check the coil so what do you guys think......I'll get a new coil tomorrow cause I should have a spare hanging around anyway.

 

[crucial118]

Running lean maybe?

 

[GuysMonteSS]

Might be a worn distributor gear...
Guy

 

[pontiacgp]

Thanks for the suggestion but the distributor gear is fine. I think crucial has it right. It's in the carb. The accelerator pump came up bad whch is very strange since that pump is the blue rubber which was put in last year and I don't use ethanol gas. It ran better with the new pump but then got worse. I thought my 02 sensor was acting up but it's not. The car is running lean and even at idle the screws don't have much effect. I just pulled out my spare carb to rebuild and I'm missing the plastic bowl....I hope my parts carb in storage has one

 

[lilbowtie]

Popping when you let off tells me you are getting fuel when the throttle is shut (possible float level) The fact that your idle screws aren't having any effect tells me your throttle blades are open too far and your off of your idle circuit. Couple of things to check.

 

[jeremyandthemonte]

Thanks for the suggestion but the distributor gear is fine. I think crucial has it right. It's in the carb. The accelerator pump came up bad whch is very strange since that pump is the blue rubber which was put in last year and I don't use ethanol gas. It ran better with the new pump but then got worse. I thought my 02 sensor was acting up but it's not. The car is running lean and even at idle the screws don't have much effect. I just pulled out my spare carb to rebuild and I'm missing the plastic bowl....I hope my parts carb in storage has one

If your carb is a qjet I have a few just sitting if you need to get some little bits of them feel free

 

[pontiacgp]

If your carb is a qjet I have a few just sitting if you need to get some little bits of them feel free

Thanks but I think I got it figured out. The carb even flooded on me which I cleared out by taking off the fue line and plugging it then rant he car till the carb ran out of fuel. The carb seems to be working much better I also had a plug gap closed on number 5 which I don't know how that happened but since I'm the only one working on the car I guess I'm at fault. With an MSD box a grounded plug messes up the box and seems to make it alot worse than only one dead cylinder. Found the bad one by the temp of the header tubes......t-tops coming off and out for a drive to visit my son and his wife of 8 days.....

 

[pontiacgp]

Great day for a drive and the GP was real quick and the bbq at my son's and his wife's place was perfect so I'm a happy man. While driving or should say parked on the highway with 30 miles of stop and go traffic I realized that I had used some Lucas gas treatment that I got for my Jeep. It was injector cleaner and I was not thinking when I put some in my GP. I wish Lucas would use different bottles and labels for their carb and injector cleaners. Now I know why the accelerator pump failed and my fuel gauge was all wacky for a few days. The gauge is just starting to read correctly. I'll be changing ther fuel filter tomorrow as well. If it wasn't for my dumb moves life would be boring....😵

 

[crucial118]

Glad you figured it out.