1989 Chevy S-10 ROUGH IDLE, 4.3L V6 TBI

72,000 MILES • 6 CYL • 2WD • AUTOMATIC
Avatar
JASONINNORMAN
  • MEMBER
  • 1 POST
I GOT THIS S10 I PAID 450 FOR IT. NEEDED A LITTLE WORK BUT THE ISSUE IT HAS I CANT FIND THE CAUSE OF. IT HAS A ROUGH IDLE. I DID THE FIRST TUNE UP ON THE TRUCK. BUT PLUGS WERE CLEAN STILL REPLACED SENSE THEY WERE ORIGINAL 89 PLUGS. REPLACED IDLE CONTROL MOTOR. CLEANED TBI. HAS CAT CONV CHECKED. SHOWS 3PSI. I KNOW IT NEEDS REPLACING. FUEL FILTER REPLACED. NO VACUM LEAKS. FUEL SEEMS TO BE SPRAYING INTO THROTTLE BODY NORMAN. WEN U COME TO STOP LIGHT IN GEAR IT IDLE BAD AND ACTS LIKE WANTS TO DIE. BUT NEVER DOES. ONCE U GIVE IT GAS ITS FINE, HAS TONS OF POWER. GETS VERY GOOD GAS MILAGE TO AROUND 20-23MPG, I WAS TOLD THE ECU TEMP SENSOR CAN CAUSE SOMETHING LIKE THIS IF IT BAD AND O2 SENSOR. NOT REPLACED EITHER. IS POSSIBLE TO TEST THEM? IF SO HOW WOULD I? TIMING IS CORRECT ALSO. NO OIL LEAKS. NO OIL IN WATER OR WATER IN OIL. EXHAUST SEEMS TO HAS A LITTLE STRONG ODER TO IT. BUT NOT LIKE A FLOODING OUT SMELL. I DONT KNOW ABOUT THE EFI STUFF. OLDER CARS I CAN FIX. CAN U GIVE ME SOMETHING TO MAYBE HELP ME ON MY ISSUE?
Oct 14, 2008 at 1:40 AM
Advertisement
Avatar
DOCFIXIT
  • ✓Experienced Mechanic
  • 18,828 POSTS
Get a timming light hook up run engine shine light on injectors observe spray pattern shoulbe smooth 360 pattern. If you see drips inj bad dirty whatever fuel puddles dose not vaporize low rough idle.
Oct 14, 2008 at 5:40 AM
Avatar
JASONINNORMAN
  • MEMBER
  • 1 POST
well i replaced the o2 sensor and well i couldnt get it out had to take to muffler shop b/c needed a tourch to heat it. but i drive it there with o2 sensor unpluged and it ran almost perfect. that more or less blew my mind. never seen that happen before. do u have a idea on wat or how that can hapen or wat cause that one? wen got new one pluged in and it started running rough again. im just so lost. let met know if u have a idea about it. ill try the timming light with ingectors.
Oct 14, 2008 at 7:00 AM
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Frequently Asked Problems for This Vehicle