I didn't build my engine, but with the problems I have been having, it looks like an internal engine issue, and while out with some friends one said the he has seen an LT1 get a cam install in which the timing marks lined up correctly, but the cam was off causing it to run like crap. Has anyone heard of this problem? My car goes back to the shop for a leakdown test tomorrow, and I was thinking a leakdown should reveal this problem, due to the fact that the valves will be open at the wrong times...Does this spound plausible?

 

Describe how your car runs like crap? Rough Idle/ Power Loss? Heats up? What is it not doing right?

 

It's like the timing is way off...It misfires horribly, runs pig rich, and is WAY down on power. The dyno graph looked like it was the grand canyon.

 

I have heard some cams run funny if not degreed correctly according to what the maker of the cam suggests. The guy who is doing my install said that if its not degreed correctly the power could be too peaky (no low end at all) or too lowend (no topend).

 

Well, I think this is a lot worse off...It's more like the car is running on 4-5 cylinders, literally.

 

Have you verified that dots line dot to dot? cam at 6, crank at 12, cam dowel at 3, and crank keyway at 1.5?

I am just commenting because I too am going to the same problem, thing is that I already have verified chain alignment is correct.

Are you getting any error codes, possible injector driver malfunctions? Could be stuck open, that would definetly cause the same symptoms.........

What have you done so far?

 

I've replaced the entire fuel system on the engine, the opti, the PCM, and every major engine sensor. Nothing has helped. It still runs horribly. I haven't verified the marks personally, but will this week while it is at the shop.

 

Please keep us updated....

I have replaced the following: New Opti (I upgraped to vented version), new opti harness, new coil, new plugs, ignition wires, checked fuel pressure, new TPS, IAC, O'2's, MAP, IAT, ECT and nothing.....verified timing chain aligment.....checked out ok.....nothing

Symptoms are:
Huge Power Loss, - can even spin wheels, zero top-end

Low Vaccum - 7-9 inches really unsteady. MAP is around 20-22, with with BAR at 30.30 which equals 7 to eight inches.

Horrible idle - Sounds like it runniing on 5 cylinders, cylinder #1 header primary does not even get hot like the others......

Fouls Plugs in Seconds and Consistenly.......

BLMS at 108, beyond ECM control, runs super rich - burns eyes....

Shuts down at times after WOT run.....

starts hard - have to press gas pedal to get it going at times, and runs like crap under load (drive or reverse - no matter what).

Scan tool says I have two quad drivers failures (1 and 3), some say it is injector driver related, but I do not think that is all my problem.......

I am beginning to think the COMP CAMS got out a bad batch or something.... mine is XE230/236 cam........

Please keep me updated on your progess and I will do the same...


Good Luck!!!!

 

When did you get yours? I got my cam back in June. I was thinking that earlier today.

 

Nahh, I purchased mine back around December of 2002.

 

Pull timing cover if you have an after market timing chain. I'll just about bet that the crank gear is timed on one of the retard or advance notches.

Degreeing a cam isn't necessary on an lt-1. They basically only go in one way.

-Shannon

 

I have the Cloyes Twin Roller, and the keyway is at the factory setting. It is lined up dot to dot, but I need to confirm if I used tke keyway with the rounded top........it was already getting dark that day....we will see.

Thanks

 

It's a new stock chain, here....But I was thinking of going cloyes anyway.