My truck has started surging between 42-48 mph if i only give it partial throttle. I can power through it no problem, but if i'm trying to maintain that speed, it surges (RPMs, not tranny). A few weeks ago, my tailpipe rusted off at the muffler, and i haven't fixed it, i'm guessing this could be related to a lack of backpressure? Any ideas?
Thanks guys!
Surging between 42-48 mph
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- HenryJ
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Check the ignition components for the cause of the surge.
I tried the Bosch Platinum plus four plugs and developed a surge at cruise speeds. The rpms would jump a few hundred rpms. Sounds like a similar situation that you have.
The tail pipe rotting off can be several things.
The system needs to warm up to burn out the condensation that is formed. Pipe size and driving habits can play into the life of a system. If your pipe is big it may take a long time to heat up. If your commute is short there may not be enough time to warm up. You can try smaller pipe , but that comes with an increase in back pressure. Driving a longer time is not usually an option. The next is to use pipe that will last longer. Stainless steel is the choice for most systems, but it too can fail. I used 3" aluminized pipe. I do live in a desert climate though.
Back pressure should be unrelated to the rotting tail pipe, or at least I do not see a relationship, other than heating the system. In the tail pipe after the muffler, that should not be part of the equation.
I tried the Bosch Platinum plus four plugs and developed a surge at cruise speeds. The rpms would jump a few hundred rpms. Sounds like a similar situation that you have.
The tail pipe rotting off can be several things.
The system needs to warm up to burn out the condensation that is formed. Pipe size and driving habits can play into the life of a system. If your pipe is big it may take a long time to heat up. If your commute is short there may not be enough time to warm up. You can try smaller pipe , but that comes with an increase in back pressure. Driving a longer time is not usually an option. The next is to use pipe that will last longer. Stainless steel is the choice for most systems, but it too can fail. I used 3" aluminized pipe. I do live in a desert climate though.
Back pressure should be unrelated to the rotting tail pipe, or at least I do not see a relationship, other than heating the system. In the tail pipe after the muffler, that should not be part of the equation.
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Jigg,
Could you take the time to add the yr of your ZR2 to your profile? A model yr might help someone with a little knowledge. I know, I know, I won't be affected. I can't remember from "the Mother Ship" what you had but, I know, I had the problem in my '97 ZR2 similar to yours and SeaFoam corrected it.
Could you take the time to add the yr of your ZR2 to your profile? A model yr might help someone with a little knowledge. I know, I know, I won't be affected. I can't remember from "the Mother Ship" what you had but, I know, I had the problem in my '97 ZR2 similar to yours and SeaFoam corrected it.
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Reed is right about injectors causing a similar symptom. Make sure the ignition is in good shape then look there.
Be sure to heed the warnings about the plastic distributor. I hate to see a simple check wind up being a housing replacement $$$
Be sure to heed the warnings about the plastic distributor. I hate to see a simple check wind up being a housing replacement $$$
"Speed doesn't kill, suddenly becoming stationary does." - Richard Hammond
"Speed is just a matter of Money - How fast do YOU want to go?"-Mechanic from Mad Max-
If at first you don't succeed - Don't take up Skydiving! - ThunderII KE7CSK
Sounds good. Thanks guys!
I actually had to replace the distributor on my last blazer (different reason, but i f-ed up that housing too). Not something i feel like doing again, so i'll be cleaning that threadlock as much as possible
I actually had to replace the distributor on my last blazer (different reason, but i f-ed up that housing too). Not something i feel like doing again, so i'll be cleaning that threadlock as much as possible
[size=75][url=http://www.synergyoffroad.com]Synergy Offroad[/url][/size]
How fast does the surging happen? Kinda of a slow rise and fall, or fairly rapidly?
I had more of a bucking happening with my 99 Bravada that was a tranny problem.
Try just VERY lightly touching the brake pedel when it happens and see if it goes away, touch it just light enough to turn the brake lights on, not enough to engage the brakes.
Just a thought.
I had more of a bucking happening with my 99 Bravada that was a tranny problem.
Try just VERY lightly touching the brake pedel when it happens and see if it goes away, touch it just light enough to turn the brake lights on, not enough to engage the brakes.
Just a thought.
[size=75][b]1991 GMC Sonoma Extended Cb[/b] - 4.3L Automatic, 2" BL, 31" BFG's.
[b]1992 Chevy T-10 Reg Cab[/b] - 4.3L 5spd, 3" Bl, 31" Mud Tires. Hooker long tube headers and true duals.
[b]1999 Oldsmobile Bravada[/b] - Wifes truck, all stock.[/size]
[b]1992 Chevy T-10 Reg Cab[/b] - 4.3L 5spd, 3" Bl, 31" Mud Tires. Hooker long tube headers and true duals.
[b]1999 Oldsmobile Bravada[/b] - Wifes truck, all stock.[/size]
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Glad to hear it. The SeaFoam also freed up the float a little in my 97's fuel tank but, not much.Jigg wrote:I put some 20gal techron concentrate in it. All better! I think you were right with the injectors Reed!
[size=75][b]"For those who have fought for it, [i][color=red]FR[/color][color=white]EE[/color][color=blue]DOM[/color][/i] has a taste that the protected will never know."
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