It's been pretty hot around the past few days (95 - 100 degrees) and my '94 coupe just started acting up. Here are the symtoms:

- bogging down when trying to accelerate
- missing (sputtering)
- backfiring (once in a while)
- can't really acclerate past 65-70 (won't upshift)

I took it directly to my local mechanic to get his opinion. He took it for a spin and noticed the same symptoms. The engine was not overheating, the oil and fuel pressure was fine, the spark plug wires (Taylor) were fine. He's thinking something to do with the ignition. Oh no, please don't say the "O" word! I just spent $250 today to get a window motor replaced. I'm thinking of taking it to the Chevy dealer tomorrow. Please... I need some advice. What else can I check? What do you think it might be?

Thanks!


[Modified by mshipon, 6:58 PM 8/10/2001]

 

When my opti went, the first time, the car would do fine until the engine warmed up a little. I could sit there and rev the engine up to whatever I wanted to when it was first started. As the engine heated up, somewhere around 190 degrees, the max rpm I could turn lowered gradually until it got to about 3000rpm max. Then it started with your symptoms and would shut down a few moments later. I guessed it was the bearings in the opti heating up and finally seizing. When I took the opti apart, the bearings were melted. I couldn't turn it by hand. Maybe there is something else that will cause the same symptoms. I'd do the voltage check to see if power is going to the opti. Then see if the signal is coming from the opti. In both of my cases, power was getting there, but no signal was coming out. Do you have the shop manuals?

jimilane

 

Sounds like the Opti too me!
Been there, done that.
They really arent that bad to replace, just expensive!
Be sure to add the vent kit as described in Corvette Fever!

 

OK... so how much is this going to cost at the dealership? :cry

 

Can you find a cosigner?

 

A dealer in Atlanta quoted me 650 just for the opti. You can get one for 300 for 94 model from places like http://www.paceparts.com. I would consider changing the waterpump if it has over 40K on it as well.

 

This does NOT have to be a dealer fix if you have even basic mechanical skills. Alot of us on here have done this and it isnt really as imposing a repair as it may seem. Some of these folks have paid BIG $$$$ like in the high 3 figures to get this done just for labor.

There are any number of us that can/would/could talk you through this.




[Modified by MCPOWHITE96, 12:37 AM 8/11/2001]

 

I called just to see how much the dealership would charge one time. The exact words were " It'll tear $1000 all to H_ll". I know the whole distributor and cap assembly is $610 where I live. I ordered my cap from The Last Detail, I think is was about $230 or something. But they didn't include the middle plastic part with the seals. I got a reman distributor from a local shop for $159. I wish I had gotten it all brand new though. The first reman came apart. A small torx head bolt inside the distributor came off and got lodged in the rotating part of the distributor. Stopped me cold. The reman had a one year warranty, so I put in another reman. If I had it to do over, I would just buy the whole assembly all together.

I ran into this problem when trying to buy parts seperate. They sometimes try to give you a '95 or a '96 cap that has to be modified to make it work on the other LT-1's because the wire going to the distributor plugs into the cap part on the '95 and '96's, not the distributor, I'm not sure about '94's. You have to cut a place in the '95 and '96's cap to make space for the distributor connection that is located on the distributor on the other LT-1's. The cap from The Last Detail is the right one for the older LT-1's, it just doesn't come with the middle part with the seals you need. They said they sold the middle part as part of the distributor. Other venders said they sold it as part of the cap. So...... if you decide to peice one together, be sure of what you are getting. The folks here at the forum seem to have connections everwhere, someone should be able to set you up cheaper than buying one from the dealership.

jimilane

 

completely agree with the above on the waterpump if not already changed. Belts/hoses/plug wires while its apart would save time/agravation later also.

 

If you want to permanently fix it, buy a new distributor and modify it for air purge for $20 and seal it per C4 Tech Tips. Alternately, if there is not too much rust inside and the bearing isn't rough...you can remove the cap and clean it or buy a new cap for $140. Then perform the same sealing and purging mods.
>>If you perform these steps, you will be able to drive without worry and wash the motor. With proper Optispark sealing, a new water pump is an ill-directed effort & a waste of money. If you or a dealer throw a new, poorly designed Optispark on...it will result in poor reliability & another failure in a few years.

 

Call Jeff Kopp (18carfan on this forum) at 1-800-728-8267. Best price on the Opti by far. Most learned opinions I received so far on the venting say to modify the old style cap ala the corvette fever article Feb/ 2001. The late model caps have sealing problems when adapted to the old style Opti. Another mod option to the corvette fever version is to plug the center and pass side weep holes with JB Weld and just vent the driver side hole via drilling out and using a single 90 degree fitting. Oh well, you probably wanted to put on a neat set of plug wires anyway :(

 

Louis... you're right about that. Jeff definitely has the best prices in town for GM parts. I emailed him today. Hope to hear from him on Monday and get the Optispark and waterpump sent overnight to me. I have a really good mechanic in town who will do the install for me on Thursday. I've given up on our local dealership :smash: ... what a bunch of idiots.

 

MCPOWWHITE96... fortunately, I changed the S-Belt, plugs and wires not that long ago, but I will be changing the waterpump with the spark. I also want to get the cam cover seals replaced. I'm leaking a little bit of oil from them.

Thanks,

 

I have a brand new optispark and water pump which I bought from Jeff Kopp a couple of months ago. I never used them and they are still in the sealed boxes.

Here is the problem, they were bought for a 1994 Z28, and I do not know if they are the same part number.

I will sell them both to you for $400 plus shipping if htey will work. Here are their part numbers, so you can check if you are interested.

Water pump
GM Part No. 12527741

Opti
GM Part No. 10457702

If you do check and they are the wrong part number for the Vette's LT1, then let me know.

Good Luck.

 

I good friend of mine from Spindle City Corvettes wrote:

Am I jumping to conclusions with the OptiSpark? I don't think so, but...


[Modified by mshipon, 11:57 AM 8/12/2001]

 

I waited until the car was acting up to do the checks. Mine would NOT throw a code until the car actually quit running.

jimilane

 

Martin,

The opti does not set a code when it goes out. I would pull and check the O2 sensors as well to see if they are clogged. They are a maintenance item and should be replaced regularly. I had a problem with one of mine once and the car would not go past 105 or so with my foot on the floor. Replaced it and everything was back to normal.

 

I had a DTC 16 both times the opti had problems. The car had to actually QUIT RUNNING for it to set though. The DTC 16 in my shop manual traces one of the causes to the opti. I don't see a specific code for the opti, just the dreaded DTC 16 after everything messes up.

jimilane


[Modified by Jimi Lane, 1:19 PM 8/12/2001]


[Modified by Jimi Lane, 1:20 PM 8/12/2001]

 

The car's running rough all the time now; cold and hot. It must be ready to crap out... :blueangel: Still no code.

 

Mine did not set any codes also.