Lt-1 ??

[Jeff Griffin]

can you answer this one,my daughter has a 96 z-28 with an lt-1 in it, all of a sudden this thing started running ruff so i checked it out and found out the # 7 plug wire was melted on the heat sheild,so i replaced the wires/plugs,but now it'll start up fine idle good but when you let it warm up i took it around the block and seems to have a hesitation between maybe 2500-3000 rpm,i don't really want to take it to a dealer my $$ not that long at this point..any suggestions on this the car has 115,000 on it.. thanx for any input or suggestions on where i can start my diagnosis??

[RayL]

Make sure the waterpump didnt start leaking and get the distributor wet. Common problem on those cars.

[Jeff Griffin]

[QUOTE=RayL;289679]Make sure the waterpump didnt start leaking and get the distributor wet. Common problem on those ca

[Rick_R]

how is the fuel pressure? when was the filter changed last?

[Jeff Griffin]

how is the fuel pressure? when was the filter changed last?

good, last summer

[ls1matt]

Sounds like an opti spark taking a shit to me

[Suicidal Racing]

yep i'm going with the opti they are known to go bad all of a sudden..a couple of my friends who have them always got a spare in there car.

them cars do run nice though my friends runs 7.50s with about nothing done to it and with more tunning he will probley be in the 30s..he runs a 180 dry shot on it but its more around 150 with the pressure he runs on the bottle

[Jeff Griffin]

Sounds like an opti spark taking a shit to me

how much is this gonna cost me??lol any suggestions or preference where to pick one up??thanx for the response..

[315plus]

Had an lt-1, and changed many opti sparks... it is very hard to do on a stock , and alot of $$ in labor.. mine had motor plate, no accessories, no heat/ac, so it was no sweat

[LTLHOMER]

Had an lt-1, and changed many opti sparks... it is very hard to do on a stock , and alot of $$ in labor.. mine had motor plate, no accessories, no heat/ac, so it was no sweat
I bet you really miss those days! lol

[titter]

I am new to this site, but was referred by a good friend of mine at the NMCA event today here in Bradenton. Like said this could be an early sign of a bad opti, which generally run around $300-400. The mileage on the car, if the opti hasn't been changed in the past, could be your problem. The 96 has a vented opti, and usually will last a lot longer than the original design. MSD also sells an aftermarket opti now, that takes care of the optical sensor failure the GM models have. First though I would check the ICM, they don't like to get hot, and usually cause mid to higher rpm sputters. Another common problem is a bad coil, which can also cause a high rpm sputter. Both of these are a lot cheaper then buying a new opti.

Check out this site:
http://shbox.com/1/4th_gen_tech1.html

It has a lot of information on the 4th Gen LT1's, along with some how-to's on how to check if the opti is bad. It also will explain a few mod, to help move the ICM bracket, to let it get some cooler air.

Hope to have helped.

[9SEC6SPD]

hmm, opti. they really do suck. it really isn't that hard to change. imo. get the summit one and replace it. they do at least come with a warranty. also autozone sells them, in separate components. did you see any codes come up? if not it may NOT be the opti.

just don't overlook the simple stuff! I have been there and done that! go back over all of the wires to make sure they are on. i mean if it was fine before the melted wire it might be an easy fix, maybe one of thewires isn't fully engaged on the opti.

g'luck with it.

[Jeff Griffin]

hmm, opti. they really do suck. it really isn't that hard to change. imo. get the summit one and replace it. they do at least come with a warranty. also autozone sells them, in separate components. did you see any codes come up? if not it may NOT be the opti.

just don't overlook the simple stuff! I have been there and done that! go back over all of the wires to make sure they are on. i mean if it was fine before the melted wire it might be an easy fix, maybe one of thewires isn't fully engaged on the opti.

g'luck with it.

I posted this and somone e-mailed me and the car has been sold,thanx for the input guys.