Service engine soon.....
Thread Starter
Instructor
Joined: Aug 2004
Posts: 179
Likes: 0
From: Florida
Service engine soon.....
Ok, my '86 has been running like a champ but today after a 1 hour drive and shutting it off for 30 min., I restarted it. It idled like crap, would stall from time to time. I gave it some throttle and it would studder then rev up fine. The service engine soon light came on but while I held the car at a constant high idle the SES light would go off and it reved fine again but for the most part the light stayed on. I took my paper clip put it in A+B ports to get the code and after the three code 12's the light would just stay solid. Any ideas before I HAVE to take it to the dealership? Thanks in advance.
PS: This is not a new tank of gas, I got it last week and I have ran about half out. No new add on's or mods of any sort in a month now.
PS: This is not a new tank of gas, I got it last week and I have ran about half out. No new add on's or mods of any sort in a month now.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Every code flashes three times. Then the next code flashes three times. If no codes are set, it should flash code 12 until the cows come home. BUT since the light came on while it was running, you KNOW you have a code set. My service manual makes no mention of a steady SES light. Check yours. If you need one, go HERE. I agree, it sounds like an ECM problem.
RACE ON!!!
RACE ON!!!
Thread Starter
Instructor
Joined: Aug 2004
Posts: 179
Likes: 0
From: Florida
I have a manual. I'm thinking it MAY just be a "fluke" so I'm going to check and clean the engine controls ground, clear the code and then take a road test. When or if the code comes back I have a buddy with a code scan tester them maybe I can actually get the code. Though the car is a '86 it ONLY has 8200 miles on it and has been in a climate controlled garage so I'd imagine the ECM being bad is doubtful however possible. I'm thinking a bad fuel pump ormaybe the engine controls ground just being loose or corroded. I'll update tomorrow.
Team Owner
Joined: Sep 2001
Posts: 62,155
Likes: 1,731
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Pull codes before doing anything.
I highly doubt its the ECM, that is almost never the problem. Things like the MAF tend to cause this problem.
I highly doubt its the ECM, that is almost never the problem. Things like the MAF tend to cause this problem.
Thread Starter
Instructor
Joined: Aug 2004
Posts: 179
Likes: 0
From: Florida
Originally Posted by vader86
Pull codes before doing anything.
I highly doubt its the ECM, that is almost never the problem. Things like the MAF tend to cause this problem.
I highly doubt its the ECM, that is almost never the problem. Things like the MAF tend to cause this problem.
LOL, thats the whole problem.......I can't get the code. It flashes the code 12 three times like its supposed to then the SES like just goes solid instead of giving me the trouble code. I was thinking of taking a look at the MAF tomorrow. I've been here at work for my 24 hour shift today thinking about the car and not being able to work on her is KILLING ME!
Thread Starter
Instructor
Joined: Aug 2004
Posts: 179
Likes: 0
From: Florida
Ok, I cleared the code, fired her up and went for a test drive....everything fine YESTERDAY. Today, fired her up and the SES light came on "car running fine" so I broke out the the tester and it showed me a code 43. One book says a code 43 is the knock sensor and the book for the code tester says to check the electronic spark sensor for low voltage.
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
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
Originally Posted by proemtpff
Ok, I cleared the code, fired her up and went for a test drive....everything fine YESTERDAY. Today, fired her up and the SES light came on "car running fine" so I broke out the the tester and it showed me a code 43. One book says a code 43 is the knock sensor and the book for the code tester says to check the electronic spark sensor for low voltage.
I'm still struggling with a code 43... I am at a loss for the cause.