Question for Tom Hendricks on 96 LT-1

[Joe R.]

Tom,

My 96 has bit the dust! Went to lunch and returned to the garage with no problem. Won't start now. No spark at the plugs. Have felt a miss a couple of times and noticed the amp meter jump negative on occasion.

Watered the opti-spark a few thousand ago but was successful in drying it out with air.

Should I go for the opti-spark or something else.

Thanks for your time,

JR

[Wayne W.]

Re: Question for Tom Hendricks on 96 LT-1

More than likely. What codes?

[Terry M.]

Re: Question for Tom Hendricks on 96 LT-1

JR -- I am not Tom, BUT ... IF you have NO spark at all I would look in this order:
1) the coil wire -- they are notorious for failure -- I carry a spare at all times
2) the coil high voltage tower -- check for corrosion at the coil wire connection
3) the ignition module -- it will fail suddenly and leave you walking
4) the coil itself
5) the Opti distributor

You are sure it is a lack of spark and not the fuel pump going TU?

After 230+ K miles on each of two different GenII LT1s I (yes, I mean a total of 460K miles -- I love these things ) have found ALL of those failures at different times.

[Joe R.]

Re: Question for Tom Hendricks on 96 LT-1

Wayne, it's gotta run before you can store codes.

Terry, this one has 238,000 miles on it and this is it's first burp! Gotta love a Corvette or any GM with that many miles. And oh, yes I am sure there is no spark. Held a couple of plug wires and no juice. I'm betting on the Opti-spark! Washed it down about a year ago and had to blow the water out before it would start.

JR

[Terry M.]

Re: Question for Tom Hendricks on 96 LT-1

Hey you are right at the mileage sweet spot. Keep us posted -- I want to know what is next for me.

[Tom H.]

Re: Question for Tom Hendricks on 96 LT-1

Hey Joe !!!!

That's a tough one. I hate to try and diagnose this one online. I wouldn't want to just throw parts at it. Terry has probably given the best advise. Let us know what you find. If I had to guess, I'dsay opti spark.

[Wayne W.]

Re: Question for Tom Hendricks on 96 LT-1

Always amazed by young engineers that don't learn from the past. We know from the 30s and earlier, that is no place to put a distributor. For example the early ford V8 with it in the same place. What could go wrong there? Road grime and moisture, oil from the front seal, and valve covers, water and antifreeze from the water pump, no problems. Not to mention the ease of working on the damn thing. Try to change the rotor and cap on that thing, easy maintenance.

[Bill H.]

Re: Question for Tom Hendricks on 96 LT-1

Wayne, it's gotta run before you can store codes.

Terry, this one has 238,000 miles on it and this is it's first burp! Gotta love a Corvette or any GM with that many miles. And oh, yes I am sure there is no spark. Held a couple of plug wires and no juice. I'm betting on the Opti-spark! Washed it down about a year ago and had to blow the water out before it would start.

JR

Joe, I think codes would be stored just by cranking (with no start). I've only pulled codes once on a 96, with a reader. But the ODB I, 92-95 will store codes in "History" even with a no start.
I do know that jumping the ADL on a 96 shows incomplete code numbers on the dash, a DTC P0103 will show up as 03 so it works better with a reader.
I can post the 96 code list if needed.

[Dick W.]

Re: Question for Tom Hendricks on 96 LT-1

Always amazed by young engineers that don't learn from the past. We know from the 30s and earlier, that is no place to put a distributor. For example the early ford V8 with it in the same place. What could go wrong there? Road grime and moisture, oil from the front seal, and valve covers, water and antifreeze from the water pump, no problems. Not to mention the ease of working on the damn thing. Try to change the rotor and cap on that thing, easy maintenance.

Learning from several years of driving flathead F**ds, I learned to carry a spare distributor and could change it out in just a few minutes.

[Joe L.]

Re: Question for Tom Hendricks on 96 LT-1

Joe, I think codes would be stored just by cranking (with no start). I've only pulled codes once on a 96, with a reader. But the ODB I, 92-95 will store codes in "History" even with a no start.
I do know that jumping the ADL on a 96 shows incomplete code numbers on the dash, a DTC P0103 will show up as 03 so it works better with a reader.
I can post the 96 code list if needed.

Bill------


There might also be codes stored from when it was still running, including pending codes, that might point toward the source of the problem.

[Bill H.]

Re: Question for Tom Hendricks on 96 LT-1

Bill------


There might also be codes stored from when it was still running, including pending codes, that might point toward the source of the problem.

Yep, though I'm not sure if the 96 differentiates the current codes from history like the some of the ODB I's do. Codes on a 92-93 can change from "C", current to "H" history when you turn the key off, especially if they're intermittent.
And codes will be stored (available for recall) until they are cleared or the battery is disconnected.

[Edward J.]

Re: Question for Tom Hendricks on 96 LT-1

Tom,

My 96 has bit the dust! Went to lunch and returned to the garage with no problem. Won't start now. No spark at the plugs. Have felt a miss a couple of times and noticed the amp meter jump negative on occasion.

Watered the opti-spark a few thousand ago but was successful in drying it out with air.

Should I go for the opti-spark or something else.

Thanks for your time,

JR

JR , I would take alook at the coil wire towers at both end and look for corrosion problems at the termails first, and if no problem there look at the water pump area when they leak they will leak anti freeze on the opti dist.mositure sometime makes its way under the cap , that will create havick with ing. system, it fogs up the opti lens and you know how a engine reacts with a wet cap- misfires and just plain old running rough.Also since you had a problem with water before it may have never totally dryed up sometimes mositure will just sit under the cap with no way to get out. so pulling the water pump and removing the cap maybe the next thing.

[Joe R.]

Re: Question for Tom Hendricks on 96 LT-1

Just an update on the 96! Opti-spark was the problem. I also repaced the plug wires, coil and ignition module while I had her apart. I would suggest that if somebody wanted to replace those items, it is easier to pull the entire engine. There is no way a large, old (fat) person can work on an LT-1 engine in a C-4!!!!!!!!!! Do you people realize that you have to pull the harmonic balancer to replace the opti-spark??? And that is nearly impossible on a C-4!!!!
Thanks for all the suggestions from everyone. Thanks goes out to Terry since he has already been there and walked the walk!

JR

[Terry M.]

Re: Question for Tom Hendricks on 96 LT-1

Just an update on the 96! Opti-spark was the problem. I also repaced the plug wires, coil and ignition module while I had her apart. I would suggest that if somebody wanted to replace those items, it is easier to pull the entire engine. There is no way a large, old (fat) person can work on an LT-1 engine in a C-4!!!!!!!!!! Do you people realize that you have to pull the harmonic balancer to replace the opti-spark??? And that is nearly impossible on a C-4!!!!
Thanks for all the suggestions from everyone. Thanks goes out to Terry since he has already been there and walked the walk!

JR

[Joe L.]

Re: Question for Tom Hendricks on 96 LT-1

Just an update on the 96! Opti-spark was the problem. I also repaced the plug wires, coil and ignition module while I had her apart. I would suggest that if somebody wanted to replace those items, it is easier to pull the entire engine. There is no way a large, old (fat) person can work on an LT-1 engine in a C-4!!!!!!!!!! Do you people realize that you have to pull the harmonic balancer to replace the opti-spark??? And that is nearly impossible on a C-4!!!!
Thanks for all the suggestions from everyone. Thanks goes out to Terry since he has already been there and walked the walk!

JR

JR------


I don't think you need to pull the harmonic balancer. However, you do need to unbolt the balancer from the hub.