Ok, as of late whenever I run my car for a while it stars to have detonation problems.

At first I thought it was just the engine getting hot, but I put a 160 stat in and now the engine stays much cooler, but the problem is still there.
And it seems to be slowly getting worse.

When I first start my car up (cold start) it runs great, and fast. But as I drive it weather hard or not, city or highway after a while it starts to lurch if I give it much throttle.
The longer I drive it the less throttle/rpm I can give before it starts lurching.

Yesterday it got so bad it was lurching, and seemably detonating just to keep it moving.

I cant understand what is going on.
Like I said the engine is plenty cool.

My best guess is the fuel pump is starting to go out, and when it gets hot it isnt sending enough fuel. But could running lean cause detonation even when your barely touching the throttle?

Any other ideas what it could be?
I might think the opti, but it was doing it really bad last night, but I was on the highway and it was very cool out, so I would think the opti would stay cool.

Thanks,
Adam

 

do any mods lately? do you have a check engine light? if not you dont have detonation.the light is triggered way before its audiable.

 

There's no trouble code or SES light for excessive knock retard or actual knock on an OBD-I car.

What you are describing sounds more like "misfire" than detonation. Detonation is "knock"... a second flame front developing after the spark lights the first flame front. It will sound like marbles rattling in a steel can, but it won't be what you appear to be describing.

You've got a problem with something that is excessively sensitive to engine heat.... weak coil, bad plug wire insulation, overheating ICM module, failing optical "chip" in the OptiSpark. Or, a stretch, but possible is vapor lock due to engine heat and a failing fuel pump. Get a fuel pressure gauge on it to pin down or rule out the fuel problem. Then, if the fuel pressure is OK, check the igntion side.

If you are convinced it really is "detonation", get a scanner on it and check for knock retard. You are going to get a ton of retard before you actually start to hear "knock".

 

Ok, well I suppose that is good that it is not detonation.

When it happens it seems to lurch, and to me seemed as though the fuel was getting detonated before TDC and there for causing the lurch (which is obviously more evident because its a manual rather than automatic).

For mods I have done intake stuff (K&N Cone filter, Ported MAF, and !donkey ****) and it was recently programmed.

However the car had the problem before. Although before it did only seem to happen when the engine was hot.
Now it happens after the car has been running a while reguardless of engine temp (or rather the temp the guage shows).

I havn't changed the plugs ever, and I have had it 34k miles (134k on the car total).
I have had a set of NGK TR55's sitting in the trunk, but I havn't gotten around to putting them in, because it is suppost to be so difficult.

I suppose I will order a set of Accel 300+ wires and install them both at the same time.

Hopefully that will solve the problem.

As far as the coil, exactly where is it? I know where the cap is, but I dont know what the coil looks like on an LT1. Is it like a standard cylinder looking style coil?

Any suggestions to make plug/wire installation go easier are apreciated.
Thanks agian!

 

BTW: there is no code...

 

The ICM module and the coil are riveted to a bracket bolted to the front of the drivers side head. It looks nothing like a conventional cylindrical coil.

 

Here's a picture of the coil and ICM.

http://csce.uark.edu/~jgbertr/rb/coil_loc.jpg

 

Thanks.

It looks like Coils arent too expensive, so I figured I would order one. Possibly fix a problem and add a pony or two at the same time.

So which one should I get?

Thunder has the MSD Coil, but doesnt tell anything about it.
The Hypertech coil says it provides more power.

What coil is the best to get under say $70?

 

They all provide more voltage. You can get an MSD or Accel from Jegs or Summit for around $40.

 

If the accel is pretty good, I checked today and I can get it (Accel 140011) through work for $40.

Anyone else have an opinion on which coil is best?

**Edit**
I looked up the Accel coil on summit:

Vendor: Accel/Mr Gasket Co.
Product Line: Accel Super Coils and Accessories
Material: Alkyd

Brute thunder for your HEI

GM: 1984-1995, HEI remote mount, E-core design, direct bolt-in replacement, super coil

This HEI remote mount super coil puts out 48,000 V. It is designed for 1984-95 GM computer controlled remote mount HEI systems. It features an E-core design for higher energy and voltage outputs. This coil is a direct bolt-in replacement and includes new mounting hardware.