1989 L98 engine miss
Thread Starter
Intermediate
Joined: Dec 2013
Posts: 29
Likes: 0
From: Atchison, KS
1989 L98 engine miss
Guys and gals, could use some opinions here.
I have a 1989 with the L98. I just completed a full tune on the car: distributor cap, coil ,rotor, plugs and wires: all new. The car starts but it has a miss at any throttle. It definitely runs better but now I think I have a non-functioning injector because there are no codes being thrown.
Is there an easy way to check these with a meter?
If it is an injector, I will replace or rebuild all eight injectors.
TIA for any advice.
I have a 1989 with the L98. I just completed a full tune on the car: distributor cap, coil ,rotor, plugs and wires: all new. The car starts but it has a miss at any throttle. It definitely runs better but now I think I have a non-functioning injector because there are no codes being thrown.
Is there an easy way to check these with a meter?
If it is an injector, I will replace or rebuild all eight injectors.
TIA for any advice.
Last edited by DallasP2091; Apr 5, 2021 at 11:23 PM.
Team Owner
Joined: Jul 2004
Posts: 28,472
Likes: 3,290
From: Hartford WI
Check fuel pressure. Turn the key on and not running should be about 42 psi. Turn the key off and see if it bleeds down quickly. Do a WOT run with the gauge taped to the glass and see whether the pressure is right or not.
If your injectors are Multecs, go to FIC and get a reman set and throw these into the landfill.
If your injectors are Multecs, go to FIC and get a reman set and throw these into the landfill.
Cruising
Joined: Mar 2021
Posts: 14
Likes: 5
From: Atlanta, GA
Did you reset the computer by disconnecting the battery when you did the tune up? It could be that the computer needs to adjust to the new components a bit. I had a bad part throttle miss that didn't go away after I changed a bunch of stuff, but it did once I reset the computer. I also found that checking the idle speed adjustment makes a big difference. My TPS sensor was off a bit and I think that with the ECM not seeing the throttle at idle, it was causing problems. It was only off a touch, but that small adjustment made a big difference.
Racer
Joined: Sep 2005
Posts: 385
Likes: 8
From: north branford ct
Test the injector wires with a noid light the check the injector coils with a multi meter , the procedures for these tests are in here somewhere, I did it 16 years ago and had two half *** injectors. Also while running I remember pulling one injector wire off at a time and listen or check tach for one that makes no difference and then trouble shoot that cylinder or cylinders could even have screwed up a plug or wire during tuneup?
