Stutter during acceleration
Thread Starter
Instructor
Joined: Jul 2018
Posts: 216
Likes: 36
From: Frisco, TX
Stutter during acceleration
I've had my '95 for 8 months now and it has always run like a top. The last three times I took it out, it stutters while accelerating, as if there are random misfires. Once it comes up to operating temp, all seems fine. The only coincident thing is it sat for a while and the battery was down. Almost didn't start. That was the first time is noticed it. Then the next two times i started it cold, the stutter returned. No check engine light. Any ideas? Would there be an error code if the SES light is not on?
Thanks,
Nick
Thanks,
Nick
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,214
Likes: 1,173
From: Southlake, TX
Check your coolant sensor as it may be faulty. If the sensor is faulty, the signal will tell the ECM that your engine is at operating temperature even though it is cold. A cold engine requires more fuel (rich condition) temporarily until your engine heats up. The fact that once warm your car runs fine tells me you need to check.
Thread Starter
Instructor
Joined: Jul 2018
Posts: 216
Likes: 36
From: Frisco, TX
Thanks Bill. Is that the same sensor that drives the temp gauge? I did not notice if read high on a cold start, but will check later tonight. I looked in the Service Manual and don't see anything under coolant or temperature. Where is the sensor?
Thanks,
Nick
Thanks,
Nick
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,214
Likes: 1,173
From: Southlake, TX
BTW... your gauge cluster is notorious for being inaccurate.
Thread Starter
Instructor
Joined: Jul 2018
Posts: 216
Likes: 36
From: Frisco, TX
I did find the sensor between 6 and 8. The dash gauge is operating (somewhat) properly. It looks like there are two sensors in the water pump. I found one in the service manual, 6B-24, left side of pump. Just points it out as "coolant sensor". I can't find a reference for whatever the other one is on the right side of the pump. Anyone shed some light??
Thanks,
Nick
Thanks,
Nick
Le Mans Master
Joined: Oct 2004
Posts: 6,314
Likes: 508
From: South-central Missouri
Before diving into the coolant sensor, I'd want to have a look at the plugs for clues and/or replace them while your at it - eliminating that possibility. And, simply having it scanned may provide some clues (but disconnect the battery for 30 seconds to clear any old codes). And, if it happens mostly under load and not at idle, aside from low voltage, the coil is to be considered.
Last edited by Paul Workman; Feb 17, 2020 at 07:55 AM.
Thread Starter
Instructor
Joined: Jul 2018
Posts: 216
Likes: 36
From: Frisco, TX
Nick
New sensor zip-tied
Digital temp readout from new gauge. Note analog gauge temp
Original sensor re-connected; matches analog gauge
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Le Mans Master
Joined: Oct 2004
Posts: 6,314
Likes: 508
From: South-central Missouri
A "noid light" can be used to detect ignition (spark) issues. And, if the input to the coil can be verified to be within acceptable operation parameters, then swapping out the coil to see if the ignition issue has been resolved would be a logical step.
Don't know if this is going to help. Hard to troubleshoot w/o being there. Good luck.
P.
Le Mans Master
Joined: Sep 2009
Posts: 6,311
Likes: 1,125
From: Vermilion OH
If you find that it's not a shudder caused by an ignition or fuel system issue and the car has an auto trans, you may be experiencing torque converter shudder. This requires replacement of the torque converter. This is something to consider if you are not experiencing a misfire or if you find that the fuel delivery system is in proper working order.
Thread Starter
Instructor
Joined: Jul 2018
Posts: 216
Likes: 36
From: Frisco, TX
Just a final update on this problem. It appeared to be resolved, but came back. It began stuttering at all temps, then would run fine for a while. Took it into my mechanic and took him for a test ride. He suspected plug wires. Replaced the wires and plugs. Problem gone!! Thanks Paul, Bill, and mazdaverx7 for your input. I think Bill was closest!!
Thanks,
Nick
Thanks,
Nick