C4 mid-throttle misfire
Thread Starter
5th Gear
Joined: Jul 2025
Posts: 6
Likes: 0
C4 mid-throttle misfire
Drivin me crazy.... 1995 LT1 (base) Corvette. Idles great,Wide-open throttle runs great. 20-50% throttle stumbles and bumbles and misses badly. I've replaced ALL ignition components at least once (some of which were obviously bad), but the issue never goes away. Any thoughts would be appreciated.
Thread Starter
5th Gear
Joined: Jul 2025
Posts: 6
Likes: 0
Racer
Joined: Feb 2024
Posts: 268
Likes: 113
From: New York
So the procedure would be to disconnect both O2 sensors (to be safe). Then disconnect the battery. Wait 5 minutes. Reconnect the battery and test drive. You should then be running in open loop mode with BLM and INT both locked at 128.
Last edited by C4industries; Jul 21, 2025 at 05:12 PM.
Thread Starter
5th Gear
Joined: Jul 2025
Posts: 6
Likes: 0
To run that test, you need to also disconnect the battery for a few minutes to clear the RAM and reset BLM to 128. Else, the engine will start and run in open loop mode with a BLM correction calculated from previous run cycles.
So the procedure would be to disconnect both O2 sensors (to be safe). Then disconnect the battery. Wait 5 minutes. Reconnect the battery and test drive. You should then be running in open loop mode with BLM and INT both locked at 128.
So the procedure would be to disconnect both O2 sensors (to be safe). Then disconnect the battery. Wait 5 minutes. Reconnect the battery and test drive. You should then be running in open loop mode with BLM and INT both locked at 128.
I suspect that roller-lifter noise is causing false knock-sensor activity. I set the Max-Knock-Retard to zero and ....problem solved! Not an ideal long-term solution. Should I attempt a rocker adjustment? (they don't have noticeable play, but also don't feel pre-loaded) Or should I replace all the lifters? Opinions, please?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
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
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