New Motor Wont Start! Help!

[raroZ28]

Raro, did you car only idle rough after warming up, or did it do it cold?

Z, Im getting close to that point where I might break down and just head that route. Injuneer swears by it, and many others support it. How many miles do you have on it?

The car would at least idle and drive (like total crap) when cold. Once it warmed up, it wouldn't hold idle, and once it stalled it wouldn't start.

Just do the compression check. If you have headers, it shouldn't take but a few minutes.

If your cats are glowing, then that could be the problem by itself. A clogged cat can make a car run like total s#*t. Go and run laps (on foot) until you start heaving (warm up), then start breathing through a straw and see how long after that you can run.

[Joe 1320]

Cats glowing can be caused by either a restriction, excess fuel that gets lit off in the exhaust pipes, excessively retarded timing, excessively lean mixture or a combination of any of the above.


hmmm......could be a valve isn't seated, allowing that cylinder's combustion even to occur in the exhaust rather than inside the cylinder. That puts all the heat at the cats, causing the glow.

[97Bandit]

if they glow orange and theres a smell wouldnt that sound like a cats being plugged. does it smell bad like rotten eggs? im just asking because i didnt see a ORY listed as one of the mods maybe they just started getting plugged and it got worse since you put the new motor in. ive had cars not rev up due to that. i guess you could always do a backpressure test, its easy to do, im just trying to throw some new ideas out there instead of focusing on mainly the opti.... hmm...

[AmericanZ28]

After playing around with this thing, I found a problem. If I tugged on the coil connector wires, the car would die. The contacts on the coil connector were a bit corroded and didnt appear to be gripping the contacts too well. After a bit of tweeking and cleaning, the car atleast stayed on.

However, after warm up, the car wont re-start unless I give it some gas, and I all of a sudden started getting a "Knock Sensor Performance" code. Replaced it, cleared the code,and as soon as the engine began to idle poorly, it turned on again (SES). I have a new connector on order, and I will be reinstaling my MSD 6AL.

I have the Random Tech Y Pipe with their cats, and it does smell like rotten eggs, but only when its idling(poorly) and I give it gas. It still revs fine well past 5K RPM.

[AmericanZ28]

Ok, new discovery! I turned on the car in the dark and looked around under the hood and saw very dim sparks on 3 plug boots (2 on ds, and 1 on ps). It wasn't very obvious, and almost seemed like it was comming from the edge of the spark plug boot. None of the boots were torn, and the cable appeared to be in good shape. What gives?

[Joe 1320]

Ok, new discovery! I turned on the car in the dark and looked around under the hood and saw very dim sparks on 3 plug boots (2 on ds, and 1 on ps). It wasn't very obvious, and almost seemed like it was comming from the edge of the spark plug boot. None of the boots were torn, and the cable appeared to be in good shape. What gives?

Voltage leak. The resistance in the wires climbs with heat and age. The electricity begins to find a less resistant path to ground. you aren't by any chance using the metal boot covers are you? If so, ditch them.

[AmericanZ28]

Voltage leak. The resistance in the wires climbs with heat and age. The electricity begins to find a less resistant path to ground. you aren't by any chance using the metal boot covers are you? If so, ditch them.

No Joe, no boot covers. I will replace the wires as soon as I get money for a set. 8mm Taylor seems to be the favorite. Are there any stock sized wires that perform well?

[ConElite]

Ok, new discovery! I turned on the car in the dark and looked around under the hood and saw very dim sparks on 3 plug boots (2 on ds, and 1 on ps). It wasn't very obvious, and almost seemed like it was comming from the edge of the spark plug boot. None of the boots were torn, and the cable appeared to be in good shape. What gives?

WOW

Didnt see that coming. get the taylors that are customizable. They look good and are not that expensive! Plus you can cut them to the perfect size so there is no wire hanging anywhere.

Man I hope that solves that problem. Including the Ign. Box! Maybe thats why so much raw fuel is going out the headers and settling in the cats causing them to Glow!

Ding ding ding we got a winner!

[RAF7789]

What a PITA! I just read the entire story. So there is fuel in the cats? Does it backfire when its at normal operating temp?

P.S. i have the taylor 8mm (model specific lengths) and haven't had a problem since. I found that one wire was right up against the exhaust manifold and there wasn't even a mark on the wire. Hope that solves the problem.