hardeez28

Ok here we go have a 93 z28 was running great stock .I put k&n cold air on still runs good then I finally put lt headers on it crank it a few times in my yard straight headers. When I start to drive it to the muffler shop it cuts off before I leave my yard try to crank it and nothing just turns over sound like it wants to crank a little but want .Pull it to get the true dual exhaust 1 chamber flow master mufflers and try to crank it again nothing get it home by pulling it and test the ecm 2 codes 36 and 42 so what should I check or start first .thanks for any info

93 LT1 Vette

How about learning how to type in a complete ******* sentence, that makes just a little sense before asking for help. Please

hardeez28

hey man just looking for some info on the subject didn't know I had to have perfect sentences to get help .If you didn't have an info on the subject you don't have to say nothing . Is this good enough sentences for you. thanks

ChevyOwner

Does the engine turn over, and not start? or is it that is does not turn over at all?

mab6680

iTrader: (1)

opti is gone you can check the drivers side ground the one that goes from the coil to the frame for code 42 but my money is on a bad opti

ahritchie

iTrader: (1)

OP, your punctuation skills are lacking and reading it makes my head hurt. Anyway, sounds like Opti time!

Symptoms:

* Car suddenly dies and won't restart
* Starts but immediately dies
* Extended cranking to start
* Rough idle
* Sputtering
* Backfiring
* Trouble reaching higher rpm
* Black smoke from exhaust
* Poor performance with car warmed up
* Weak plug wire spark
* Codes 16, 36, and 42 may be set

Read more: http://www.superchevy.com/how-to/031...#ixzz3EQinwJFZ

hardeez28

Car does turn over and I checked tonight it has power at the fuel injectors .I also checked the coil it has plenty of juice it was lighting my hand up lol but the spark is very very weak on plug wires

hardeez28

Still not cranking also wanted to ask since I have a few that thinks that the opti is bad would the tach jumping up and down while trying to crank be a sign of that also.

ChevyOwner

The tach jumping could be as simple as an issue with the tach filter. The tach filter and the icm are both grounded at the same spot. All my wiring diagram tells me about the ground is right side of engine block.

hardeez28

ok replaced the optispark new coil and still not cranking .its turning over and kind of wanting to crank but will not start could it be the ignition coil

MikeyC

Pull the ground off and clean it (emery cloth, sandpaper, etc) and put it back on. Let us know what happens.

96capricemgr

iTrader: (1)

To me cranking means the starter is turning the engine over not firing would be when despite turning over well it doesn't ignite are run.

hrcslam

42 - Ignition control circuit, short or grounded- check the ICM and it's grounds, wires, and connectors.

STOP REPLACING THE OPTI'S!!!!! Holy ***** people! If the injectors AND spark fails it's most likely an Opti failure. If EITHER work it's not the Opti!

So sick of this automatic blame the Opti's crap. Look at how many people replace the Opti's and it NOT fix the problem. It's nuts!

OP, put a spark tester on it (one that induces a load) and check for a GOOD spark. If your injectors are getting a signal the optical sensor is good. But the distributor (cap and rotor) could be bad.

Also, recently my machinist told me that the cheap Opti's have been pressed together wrong causing the timing disc to be more than a few degrees off from where they should be. This recently caused havoc on one of his customers cars (3 cheap Cardone Opti's in a row!). They bought a Delphi and problems were solved.

Paul Bell

iTrader: (9)

Rather then moderating this post out of existence, let's use it as an example.

Hardeez28 is a new member. Let's welcome him a little better. Not everybody is good with written word, or maybe he's using a cellphone to access the internet. There's certainly been worse writings around here.

Rule of thumb: Add something positive to a thread and be understanding of other's inexperience with cars, troubleshooting or how to pen a thread perfectly.

Paul Bell

iTrader: (9)

Now, onto the OP's issues.

Hardeez28, good advice in this thread for you. If you have spark OR fuel, it's not the opti.

Be more clear when you say it won't start. Does it crank over but not start or does the engine not even crank?

hardeez28

ok cleaned the grounds really good. Car is turning over still just fine but will not crank also sounds like its wanting to back fire the whole time im turning it over . thanks for all the info guys maybe with your help I can get this thing back running with out having to take it to somebody because im not one with trusting just anybody with working on my cars all always done all my own work but the lt1 is a lil new to me so im trying to learn how it all works but thanks for the help anything to try just let me know im game for whatever will get it running again ...

hardeez28

thanks buddy all I need is a little help with this issue .

Paul Bell

iTrader: (9)

''Turning over'' and ''cranking'' is the same thing.

Check your spark plug wires very carefully. Make sure they're in good condition and going to the correct plugs.

What spark plug wires are you using?

hardeez28

the stock wires that were on it im double checking them now to make sure there in the correct order

NickBatman

My last car was a 93. My opti was bad. Replaced that. Eventually had another issue with it cranking but not firing. Plugs and wires were new, but it ended up being both the ICM and the coil. I would check the ICM if you replaced both the coil and opti. If not, then there might have been a wire hit when you were putting the headers on. Last resort would be something like the PCM but those are rare to go out. I would check ICM.