Really rough Idle snd no power
Thread Starter
2nd Gear
Joined: Jul 2011
Posts: 2
Likes: 0
Really rough Idle snd no power
OK, I have replaced the Fuel Pump, Fuel Filter, and the relay. Finally got the car to start and run. When I took it for a ride it ran great, until I punched it. When I got it up to around 70 it was running great, when I slowed down the car felt like it had a clogged cat. Now every time I drive it I hit the gas and the car will not get over 30 mph, and the idle is rough as hell.............................HELP
7th Gear
Joined: Jan 2008
Posts: 7
Likes: 0
I'm interested in this too since my car is doing the same thing (Iroc 350TPI). I replaced the pump, and now my car surges and runs really lean at idle. I checked my fuel pressure and while running, im at 30PSI, but its steady. I tried another regulator from a buddy which is a known good regulator, but got the same PSI. I put a quarter on top of the regulator, and boosted the "priming" fuel pressure to 46 (was 40 at prime previously). I have to put the plenum back on, and see if it fixes my problem. I don't know if that would help at all, but check your fuel pressure at the rail and tell us what you get.
I also have a suspicion that my injectors may have a small leak since it drops 6psi in 30 minutes (with out the quarter in there) and 15PSI in 20 Minutes (with the quarter in there)
I also have a suspicion that my injectors may have a small leak since it drops 6psi in 30 minutes (with out the quarter in there) and 15PSI in 20 Minutes (with the quarter in there)
Last edited by camaro1185; Aug 2, 2011 at 08:00 AM.
Safety Car
Joined: Jan 2004
Posts: 3,759
Likes: 8
Le Mans Master
Joined: May 2005
Posts: 5,214
Likes: 65
From: Queensland, AUSTRALIA
Does the SEVICE ENGINE SOON light come on? What DTCs have you retrieved in what modules? What year model?
Youre not going to get any accurate help without at least 2 of the above items. The car may not even have a MAF, but no one knows cause no one asked!!
Youre not going to get any accurate help without at least 2 of the above items. The car may not even have a MAF, but no one knows cause no one asked!!
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You can check to see if the MAF is causing problems by unplugging the MAF cable. The car will run fine without it.
This problem seems more like a fuel pump problem to me. I had symptoms similar to this when the pickup sock rubbed against the bottom of the tank and shredded. The pump sucked up the fibers and the engine would run, but not well.
It might be the wrong pump or a problem with the pressure blowoff in the pump. You need to check fuel pressure at the rail to find out what's going on.
This problem seems more like a fuel pump problem to me. I had symptoms similar to this when the pickup sock rubbed against the bottom of the tank and shredded. The pump sucked up the fibers and the engine would run, but not well.
It might be the wrong pump or a problem with the pressure blowoff in the pump. You need to check fuel pressure at the rail to find out what's going on.
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
Burning Brakes
Joined: Nov 2008
Posts: 995
Likes: 1
From: Naples Campania
I had this same situation happen to me and it turned out to be timing. Since the problem happened when you jumped on the gas, I'd say it's a likely culprit. The "fork" that holds down the distributor wasn't completely tight and it rotated when there was heavy power on the cam. It's also the easiest thing to check. All you need is a timing light.
Safety Car
Joined: Jan 2004
Posts: 3,783
Likes: 15
From: Northern California
Also, check the Fuel Pressure Regulator Diaphram.
A ripped Diaphram would cause the engine to run very rich and lose power. Remove the fuel pressure regulator vacuum line and see if fuel is present. If there is, replace the diaphram.
A ripped Diaphram would cause the engine to run very rich and lose power. Remove the fuel pressure regulator vacuum line and see if fuel is present. If there is, replace the diaphram.
