Engine pulse/hesitation/stalling
Thread Starter
Instructor
Joined: Jan 2007
Posts: 131
Likes: 0
From: Silver Spring MD
Engine pulse/hesitation/stalling
My car would occaisionally hesitate if i suddenly step on it more than usual. I thought it was caused by old/clogged fuel system. Recently at an idle and at cruising rpm's (mostly regardless of gear) the engine will pulse or sag. also some times when the hesitation occurs or the pulse happens from idle, if i let off of the gas right after i gun it, (before it revs high, during hesitation, the car will stall. it is automatic btw.
any pointers? i thought dirty injectors, but now im thinking vacuum lines? any troubleshoting tips greatly appreciated.
Thanks
any pointers? i thought dirty injectors, but now im thinking vacuum lines? any troubleshoting tips greatly appreciated.
Thanks
Burning Brakes
Joined: Apr 2005
Posts: 950
Likes: 0
From: Medicine Hat Alberta
Have you recently washed the car? If so you got the optispark wet.
Did you let the car sit for a while? If so add fuel stabalizer.
If none of the 2 above I would but my money on the fuel regulator....My 96 did the same thing when I first bought it.
Did you let the car sit for a while? If so add fuel stabalizer.
If none of the 2 above I would but my money on the fuel regulator....My 96 did the same thing when I first bought it.
Advanced
Joined: Aug 2002
Posts: 73
Likes: 0
From: Oshawa ON
I took my 94 coupe out yesterday and it is exhibiting the same behaviour, unfortunately. It kind of coughs and sags as the rmps rise, but after about 10 minutes, it lessens in severity. The first time that I experienced this was about 3 months ago (last time I had the car out) after going through an automatic car wash (first time ever, I swear - it was cold). I'm hoping that my problem is not OPTI-related, but I won't know for sure until the winter ends and I can drive it more frequently. I was going to do the paperclip trick last night to check for codes, but it was too cold when I got home. I'll probably add fuel stabilizer anyway (even though the tank is full) and hope for the best.
Thread Starter
Instructor
Joined: Jan 2007
Posts: 131
Likes: 0
From: Silver Spring MD
ive been away... sorry thanks for the advice, If it helps the saging and stalls happen/get worse/more frequent when the engine temperature hot, or hotter (185-210)range.
So it is definately not a vacuum line? can I at least rule that one out?
So it is definately not a vacuum line? can I at least rule that one out?
Last edited by Slinky85; Mar 8, 2007 at 06:31 PM.
Le Mans Master
Joined: Dec 2002
Posts: 6,715
Likes: 2
From: Santa Teresa New Mexico
Got on the hiway this morning with it and punched it to get on.
It bogged untill the rpms cam up on the cam (twin cam) then it revved right up there fine.
3 miles later on a really small hill, rpms down, (5th gear) it started bucking. After I got to work 20 miles I rpmed the engine (no load) in park and it wouldnt go past 2,000 rpm. It just went flat after 2k.
On the way home samething low rpms its fine, start to pull a grade no matter how slight and it starts to buck.
Straight and level coming up on the engine slowly and you'd never there was a problem. Put your foot in and it falls on its face.
Last one of my cars did that it was the fuel filter (chevy small block fuel injected).
The fuel filters are really important in the fuel injected cars.
Wont hurt to change it, if the seats a lot the filters can cause problems.
Good luck with your problem.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Advanced
Joined: Aug 2002
Posts: 73
Likes: 0
From: Oshawa ON
I picked up a new fuel filter last year near the end of the driving season up here in the great white north. I never got around to installing it though. Definitely worth the effort this weeekend, it would seem, to see if the problem disappears.
Thread Starter
Instructor
Joined: Jan 2007
Posts: 131
Likes: 0
From: Silver Spring MD
My friend looked at my car... He immediately noticed the new heads and swore it sounded like it had an after market cam. He said the cam would do this to a car if it wasnt paired with the right stuff, like intake and injectors... Is he right, possibly? I have minimal knowledge on cams, a "performance" one would make the intake and exaustion overlap period longer right? Also, my coolant temp. sensor is dead so would that help in creating these problems? A little insight would be nice. Thanks
