Missing engine?
Thread Starter
Intermediate
Joined: Jun 2002
Posts: 37
Likes: 0
From: Bloomington IN
Missing engine?
Hey guys I have an 89 Vette C-4 with 8,370 miles. I have replaced all the fuel injectors but not at the same time. The plugs have also been changed a number of years ago. The motor has an iratic miss at idle? Anyone have this trouble before?
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: Missing engine? (Pollock)
If you changed injectors, was it because they leaked? If so, change the plugs again. If that does not fix it, the most effortless way to find an ignition problem is by doing a visual inspection with the car in the dark. Crank the car at night, un-plug the hood light connectors so there is little to no ambient light around the engine. What you are looking for is a blue glowing luminescene on a plug wire or spark plug base.
If any wire has a blue glow, it's bad. Also, if any plug has a lighting effect, it's bad. It is not uncommon for new plugs even to be bad, usually it's due to cracks inside the insulation of the plug, either from manufacturing or from over-zealous installation methods.
Other than that, a few more things that cause intermittant idle roughness are egr and valve seating problems, but thats not all inclusive, sometimes a bad ECM ( computer ) or such will cause this type of thing.
Good luck.
[Modified by BBA, 8:57 AM 6/29/2002]
If any wire has a blue glow, it's bad. Also, if any plug has a lighting effect, it's bad. It is not uncommon for new plugs even to be bad, usually it's due to cracks inside the insulation of the plug, either from manufacturing or from over-zealous installation methods.
Other than that, a few more things that cause intermittant idle roughness are egr and valve seating problems, but thats not all inclusive, sometimes a bad ECM ( computer ) or such will cause this type of thing.
Good luck.
[Modified by BBA, 8:57 AM 6/29/2002]
Thread Starter
Intermediate
Joined: Jun 2002
Posts: 37
Likes: 0
From: Bloomington IN
Re: Missing engine? (BBA)
I changed the injectors because the car would not idle or hardly even run. The ECM has been changed a few years ago. The plug wires are original and that is probably the problem, but I will try your suggestion first.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Missing engine? (Pollock)
I'd say 13 year old plug wires wouldn't help :) Get you a good set of MSD 8.5 super conductor wires. They cost a lot but are worth it. Wouldn't hurt to change the plugs again while you're into it, but I know how much of a PITA that can be.
