1994 gmc Sierra 5.7. Wont time right and backfires.

10

Asked by GuruDM9BM Sep 22, 2017 at 07:24 PM about the 1994 GMC Sierra 1500 K1500 SLE 4WD Extended Cab SB

Question type: Maintenance & Repair

I have a 1994 GMC Sierra 1500 with a 5.7 350 TBI.
Truck was running rough at high rpms when i got it.
Changed sparkplugs and put ngk wires on it. Ran
better but had no power,  distributor was off so
retimed it by ear and ran perfect all kinds of power.
Then it started to roll over worse and worse
everyday and backfireing more again. Then almost
wouldnt stay running and would stall and wouldnt
idle like it was out of time. Pulled the distributor out,
changed the ignition control module, brand new
coil, new cap and rotor button and fuel filter, and
idle air, checked the egr and seems fine, and my
ngk wires were toast wouldnt stay on so bought
new wires again. Sometimes you can time it and will
idle perfect and if u slowly accelerate it will rev to
5000rpms no prob but if u do it quick it bogs out
and flutters. Can barely get it to stay running to time
the ignition now and backfires soon as u start it no
matter where i put the distributor.  Havent had the
truck even a year yet and replaced alot of parts and
still at a loss for what could be the issue.  Cant even
set it at 0 degrees with a timing light and the
iginition advanced wire unplugged.

3 Answers

10

That actully makes alot of since. I was getting an choppy readimg from my timing light on my number 1 cylinder not consistant. Thanks i will try that tomorrow and post my results!

1 people found this helpful.
500

i would really love to know if this helped. im having very similar issues

1 people found this helpful.
10

Hey everyone phone broke had no way to answer back But replaced my pickup inside my distrubutor and it works like new no issues didnt even have to time it with the light! Thanks for ur help!

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