NemeSS

iTrader: (127)

It's possible cam was incorrectly installed. The symptom sound the same, I've come across incorrectly installed cams in ls motors, may want to verify if cam was installed correctly. I've installed trex cams and fired them up with a stock tune, didn't run em much, but fires right up and idles fine. Could also be the fuel pump like mentioned above, might as well check that out and replace filter also

MattSapp95_T/A

iTrader: (35)

Sounds like a timing issue with it backfiring...however I doubt that is it since I am sure if he builds motors he is competent enough to install a cam properly.....

I don't believe it is the tune either... But it wouldn't hurt to call whoever is gonna tune it for you and see if they can set you up with a "break in tune"

Hope you get it figured out...

kevindglenn

I had a similar problem while helping with a friend's car. I'd like to find out why as well.

Crap...should've read further in this post. It could definitely be a timing issue, from what I've experienced and have read elsewhere.

Taspeed

iTrader: (1)

sounds like the timing chain is a tooth off

Steve01SS

iTrader: (43)

What did the motor come out of originally? You mention it's a 2006?

vodas00ss

iTrader: (14)

If it fires and runs, the fuel is getting there enough to idle. If its starts and is backfiring, sounds like a timing issue. Dont think the tuning has anything to do with it. I would make sure you have the the right crank reluctor sensors stuff goin on. , I would check simple stuff like maf wires being plugged in and or broken, Grounds, tps sensor, also make sure your drinking enough beer to work on a car. Not sure where your coming from to bring your car to okc to be tuned...I took mine to texas, just sayin.

Ironembraced

*****Update*****


I got a call from my tuner. My problem is indeed an electrical wiring issue. The ECM was locked, but after the tuner got the appropriate files he was able to dig through everything. But after 5 hours of labor involved in troubleshooting, there is no solution in sight. He is at the point where his next step is to just pull the engine out of the car and go from there.

This is what I know about my issue...


* The car will start, rev, backfire and die shortly after (it ran just fine before engine was pulled)

* The ground wire on the drivers side of the block will spark if touched against the header. So I am assuming there is some sort of power source on that ground.

* Some of the grounds were either cut out, rewired or moved by the original mechanic (without my permission or knowledge of at the time). He claims there was an unnecessary amount of wires and seemed to be ghetto rigged by the previous car owner.

* The battery has been drained dead at least once, just from sitting in the garage

* The ECM and cam timing seem to be fine.

I've made plans to trailer the vette back down to the shop again so he can "try" to get it right this time. I cannot afford to shell out the cash to swap in the same engine twice. I am looking at $2100 minimum if i leave the car at the tuner. He talked about trying to get my money back from engine installer, but I can almost gaurantee the only way that will happen is through a lawsuit.

What should be my next step with this thing? I don't really know much about working on cars, but I am almost to the point where I just want to trailer the vette home and try to fix it myself.

mark21742

Bad situation man, I hope you can get it resolved quick, easy and cheap

slo2pro

dont pull the engine again. i feel that will only cause more problems in the future with wireing, is it is already an issue. i would go over every connection you can get your hands onto and even the ones you cant get your hands on. haha i have had several wireing problems with my f body, but most of them have been fairly easy fixes.. (broken wires, burnt wires, bad connectors) it sucks but sometimes its all you can do.. good luck,

Ironembraced

I am trying to figure out which wires on the engine wiring harness that could be pinched that would lead to cylinders not firing and the resulting in drivers side engine ground having voltage on it.

I just found out that my coil packs apparently are either loose or stripped out. Would a pinched coil pack wire give these symptoms?

Ironembraced

Update...

After pulling the cylinder heads we found it was only firing on 3 cylinders. The heads looked alright...but quite a few of the factory push rods were bent. The valve springs and cam has been upgraded but never ran before. I am not completely sure what exact springs were installed...but something seems really off here.


Whain the world would cause 4 or 5 pushrods to bend on fire up? 2 of the coilpacks were found to be failed...even though they worked just fine before the engine was pulled.

I just bought a house, so i am completely broke for the moment. I have no friends with a big truck or car hauler, and I have no tools or knowledge to fix this on my own...at the mercy of the mechanic here

remauto1187

iTrader: (1)

If you have a ground sparking as is disconnected/reconnected then that wire either is drawing current to apply to its load (whatever is connected to that ground wire) and/or you have a 12vdc+ that has gotten up against that groun path somewhere. Easy way to check that is put a voltmeter negative lead on the battery negative terminal and touch the positive lead on that ground wire while it is connected at its ground point. If the meter shows battery voltage here then you have a short to ground. The fact that your battery is running down while car is just sitting there is a clue to possibly your problem. Something shorted can easily cause your symptom. A short to ground can cause havoc on your PCM and even fry it. A pinched hot wire that is partially or intermittently shorted to a ground will cause havoc and can easily cause your symptoms.

You are in luck though....I am a vette owner also. (1985) and I am leaving for Oklahoma City Monday night. Where are you at in relation to OKC?

You need to keep the negative lead disconnected from that battery when the car is unattended! Do you know how fast a fiberglass car can burn? Electrical fault is probably #1 or #2 cause of Corvette fires....and they usually happen in your driveway.

7008ccGTO

Bent pushrods means to me that the cam is positioned out of time. For example, if a valve is open at he same time a piston comes to TDC, then something has to give.
A set of pushrods is relatively cheap. Hopefully nothing else was damaged. Get the cam timed properly before you bolt it up and try again. You might find OE coil packs in the parts for sale section here to save some $