1987 Corvette running poorly and bogging down! !NEED HELP!
Thread Starter
5th Gear
Joined: Aug 2022
Posts: 5
Likes: 0
1987 Corvette running poorly and bogging down! !NEED HELP!
So I recently bought a 1987 Corvette and I have been having issues with the car running properly.
the issue is as follows the car starts up ok, it takes a couple seconds but it eventually gets going, right after starting the cars rpms at idle fluctuate between 6-800 rpms before I put my foot down on the accelerator, when I put my foot down the car very roughly revs up and wont really rev very high before it starts to run very very bad, the car bogs down immediately after releasing the pedal at any rpm over idle.
What I have done to try and fix this issue is as follows:
new fuel pump, new fuel filter, new mass air flow sensor, new idle air control valve, new oem ignition module, and a new battery.
a note to add are that the car does have 200k miles, I did check the spark plugs and they looked clean, ALSO the catalytic converter is making a rattling noise which might be a problem I'm just not fluent enough with cars yet so I don't know yet. If anyone has had any similar issue please feel free to help any input is appreciated, thanks!
the issue is as follows the car starts up ok, it takes a couple seconds but it eventually gets going, right after starting the cars rpms at idle fluctuate between 6-800 rpms before I put my foot down on the accelerator, when I put my foot down the car very roughly revs up and wont really rev very high before it starts to run very very bad, the car bogs down immediately after releasing the pedal at any rpm over idle.
What I have done to try and fix this issue is as follows:
new fuel pump, new fuel filter, new mass air flow sensor, new idle air control valve, new oem ignition module, and a new battery.
a note to add are that the car does have 200k miles, I did check the spark plugs and they looked clean, ALSO the catalytic converter is making a rattling noise which might be a problem I'm just not fluent enough with cars yet so I don't know yet. If anyone has had any similar issue please feel free to help any input is appreciated, thanks!
Last edited by 87PeterC4; Aug 19, 2022 at 01:50 PM. Reason: Better Formatting.
Melting Slicks
Joined: Sep 2010
Posts: 2,422
Likes: 202
Sorry to hear that.
Ran fine. then happen all of a sudden. Or over time.?
No results with the multi parts.
What about the cap, rotor condition, timing, fuel pressure PSI, vacuum leaks. Did you pull the plenum? That plenum can give a good challenge if not familiar.
Post a sound or vid clip. Start, idle, gradual rev to 2k.
To hear what is going on.
Ran fine. then happen all of a sudden. Or over time.?
No results with the multi parts.
What about the cap, rotor condition, timing, fuel pressure PSI, vacuum leaks. Did you pull the plenum? That plenum can give a good challenge if not familiar.
Post a sound or vid clip. Start, idle, gradual rev to 2k.
To hear what is going on.
Melting Slicks
Joined: Dec 2009
Posts: 2,237
Likes: 287
I'd start with cleaning the injectors or having them serviced/cleaned. I have an injector cleaner tool that hooks up to the fuel rail and it runs on the cleaner for 20 minutes or so. The cleaner I use is BG44k.
Thread Starter
5th Gear
Joined: Aug 2022
Posts: 5
Likes: 0
so bought the corvette about a month ago in the condition I described, the guy didn't know what was wrong with it either as he didn't know really anything about cars. To be fairly honest I myself know very little in comparison to most of the people on this site, I'm just learning as I go and hoping to learn some valuable skills. I will throw up a video on my post when I wake up tomorrow though so everyone can see how it runs.
Melting Slicks
Joined: May 2014
Posts: 2,895
Likes: 592
From: New Port Richey FL
There two sounds that come from catalytic converters 1 is a tinny heat shield or pipe separation usually reduced by sqeezing with channel locks or some pressure with a screwdriver.
annoying sounds not a car stopper
Second is a hard rattle that sounds like a box of rock's rattling a very solid sound, some at first impression will say the bottom end is gone. But its not it's just the fact that the upstream converters have self destructed and are now trapped against the main converter. Bad news is if this is the case lower converter is now beaten to death also.
What does this have to do with poor running cars need to breathe and your car can't exhale, your exhaust is clogged
(Car Stopper)
annoying sounds not a car stopper
Second is a hard rattle that sounds like a box of rock's rattling a very solid sound, some at first impression will say the bottom end is gone. But its not it's just the fact that the upstream converters have self destructed and are now trapped against the main converter. Bad news is if this is the case lower converter is now beaten to death also.
What does this have to do with poor running cars need to breathe and your car can't exhale, your exhaust is clogged
(Car Stopper)
Thread Starter
5th Gear
Joined: Aug 2022
Posts: 5
Likes: 0
There two sounds that come from catalytic converters 1 is a tinny heat shield or pipe separation usually reduced by sqeezing with channel locks or some pressure with a screwdriver.
annoying sounds not a car stopper
Second is a hard rattle that sounds like a box of rock's rattling a very solid sound, some at first impression will say the bottom end is gone. But its not it's just the fact that the upstream converters have self destructed and are now trapped against the main converter. Bad news is if this is the case lower converter is now beaten to death also.
What does this have to do with poor running cars need to breathe and your car can't exhale, your exhaust is clogged
(Car Stopper)
annoying sounds not a car stopper
Second is a hard rattle that sounds like a box of rock's rattling a very solid sound, some at first impression will say the bottom end is gone. But its not it's just the fact that the upstream converters have self destructed and are now trapped against the main converter. Bad news is if this is the case lower converter is now beaten to death also.
What does this have to do with poor running cars need to breathe and your car can't exhale, your exhaust is clogged
(Car Stopper)
Thread Starter
5th Gear
Joined: Aug 2022
Posts: 5
Likes: 0
Melting Slicks
Joined: May 2014
Posts: 2,895
Likes: 592
From: New Port Richey FL
I would hold off on the sea foam there is controversy on it creating problems, I have always used the Tech-Chron for a quick clean the 3M for deep clean that hooks to fuel rail like what other had mentioned.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
5th Gear
Joined: Aug 2022
Posts: 5
Likes: 0
ok heard that, I will add that to the list, had no idea it could cause problems, thank you for letting me know. I will look into the other cleaners.