Bad Spark issue
Racer
Joined: Sep 2007
Posts: 375
Likes: 18
From: Lawrenceville Georgia
After reading your last post, I noticed you said car was popping. I know this sounds too easy but are you 100% sure plug wires are routed to the cap correctly? I have spent more than one afternoon chasing problems only to find a wire wrong. Good luck
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
By d.c. resistance, there is nothing wrong with your injectors. If you can get close enough to the engine to measure the injectors, then measure the resistance of each plug wire now! You have classic symptoms of defective plug wire/s. Look at your idling engine in the dark too!
Instructor
Joined: Jul 2007
Posts: 174
Likes: 0
From: Toronto Ontario
Check the spark plugs. If they're covered in black soot your running rich. If it pops you have too much fuel thru the injectors. Try lowering the fuel pressure a bit and see if acceleration improves.( and idle)
Last edited by trackman44; Sep 4, 2007 at 01:03 AM.
Instructor
Joined: Jul 2007
Posts: 174
Likes: 0
From: Toronto Ontario
Thread Starter
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
Now i'm not so sure it's a spark issue. Went to visit my Dad in the Vette and has that pop and stumble when you jump on it still. Long story short I had that stupid spark checker with me so I decided to hook this thing up to his Explorer for the fun of it and see what happens. I hook the thing up and start his Explorer up and this spark checker shows that his vehicle has erratic spark also. This just can't be!So now I lowered the fuel pressure some more and have to take it for a ride to see if it's any better. I was also thinking about putting the old #22lb. injectors back in putting the fuel pressure back to where it was and seeing what happens. WHAT DO YOU GUY'S THINK Pipe
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Instructor
Joined: Jul 2007
Posts: 174
Likes: 0
From: Toronto Ontario
First let us know if lowering fuel pressure did the trick. If not swap in the #22s. Before you do that make sure the #22 injectors ohm ok.
Thread Starter
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
Well I keep lowering the fuel pressure every day and it don't get any better. The adjustment bolt is just about all the way out and no change. It idles real rough and stumbles during acceleration. All the plug wires are routed correctly. I'm gonna pull a few plugs and see if they are black. 
Pipe THANKS
Pipe THANKS
Instructor
Joined: Jul 2007
Posts: 174
Likes: 0
From: Toronto Ontario
ok then you should have the ignition module checked to see if it's still good. also check distributor to ECM connections. Also if you have the original coil use it just to eliminate the possibility that the new coil has compatability issues with the stock ignition module. Don't forget to set base timing.
Last edited by trackman44; Sep 6, 2007 at 07:30 PM.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
I don't know why we can't get you to measure the resistance of your plug wires or look at the plug wires in the dark of night to see if it is sparking along any of the wires, but your symptoms are SCREAMING bad plug wires.
My 87 developed a miss on the second day after new AC plug wires were installed and I found an open circuit plug wire. Fortunately I saved my old wires and replaced the defective new plug wire until I got it replaced.
My 87 developed a miss on the second day after new AC plug wires were installed and I found an open circuit plug wire. Fortunately I saved my old wires and replaced the defective new plug wire until I got it replaced.
Last edited by jfb; Sep 6, 2007 at 09:03 PM.
Thread Starter
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
Tonight for the hell of it I popped the hood and fired up the car and looked at the wires. 3 were sparking 1 really bad 
i'm gonna get a good set of Moroso ultra 40 racewires 
Pipe I can't believe the wires went bad that quick they haven't been on the car that long.:o
i'm gonna get a good set of Moroso ultra 40 racewires Pipe I can't believe the wires went bad that quick they haven't been on the car that long.:o
Thread Starter
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
Ok I replaced all the wires. I had to install the ends on the dist. side of the wires. Shouldn't have to do that on a $125 set of wires. Anyway got em on and all zip tied out of the way real neat and fired the car up at night and #1 was arcing again. (this can't be they are brand new wires) so I pull the plug and find a hairline crack in the porcelin on the plug. I just got back from gettin a new one replaced it and no arcing. Finally all problems solved. After I threw all those parts into it I bet they are all good. Anyway THANKS SO MUCH GUY'S YOU ARE ALWAYS A BIG HELP Pipe
so I pull the plug and find a hairline crack in the porcelin on the plug. I just got back from gettin a new one replaced it and no arcing. Finally all problems solved. After I threw all those parts into it I bet they are all good. Anyway THANKS SO MUCH GUY'S YOU ARE ALWAYS A BIG HELP Pipe