I put longtubes on my 94 z28 cause the manifolds were leaking. While i was there i replaced the wires because one had melted through and the car ran like crap, so quick fix i replaced that wire and it ran fine. I did new plugs and wires (ngk tr55 and msd super conductor wires) and the longtubes at once. The car ran good for a minute but hesitated off the line. I put the lt4 km in it didn't help. Now at night i noticed that under the coil there is a fireworks show going on from i dont' know what. I replaced the coil and wires and everthing and i cant figure it out. The car hesitates and backfires bad. Could this be the opti grounding out or gone bad sparking to the water pump or something cause there is nothing under the coil that i can see would cause that except the opti. Any help would be appreciated cause otherwise i'm gonna have to take it somewhere. Thanks.

 

Did the problem occur before you did the headers?

Is the coil still arcing?

Check the coil by plugging a plug wire and a plug directly into it. Have someone crank it over and see if it's consistant. If you have an inductive timing light, you could use it on the coil wire while it's idling to see if you are dropping spark occassionally.

 

Well the backfiring is probably due to the fact that you are running rich. There will be a time delay from the 02's because you have moved them farther down the line. Because they were thinking they were still in the stock location. That will cause you hesitation off the line. Same thing happened to my car, would try to get going but seemed like it would take alot of extra effort. Triend replaing my SLP loudmouth with a flowmaster muffler cause i thought it was back pressure. That helped somewhat but didn't solve the problem totally. What fixed it was when my friend did a quick street tune with LT1 edit. Once i had a tune they problem went away and the car works fine.

 

When you changed the wires, did you change the coil to opti wire?

 

the timing is consistant but its still arching under the coil like crazy. I did change all the wires to the plugs and to the opti and its a new coil.

 

sounds like one of your wires may have tangled w/ your serpentine belt, cutting it slightly, or completely....could even be more than one....put the car on ramps/stands and crank it, then crawl under it.....see if you dont have a problem w/ your wires-to-opti. If you didnt get one on all the way, it could have slipped off also.

Billy D.

 

If its sparking like that the opti is fine because it has fire in the wires, did you reroute the wires over the vlave covers? Stock routing is just trouble

 

they are routed stock but there are no wires near where it is arching, i had taylor wires before and they sucked. They sparked to anything metal within an inch of them through the insulation. But if you look under the coil its the water pump and thats were the arching is coming from not near any wires so i got no idea. and believe me, i have quadruple checked that all the wires are tightly on and that they aren't near the belt, headers, or any moving object.

 

What kind of coil did you replace it with... and where is the arcing comming from exactly?