Saw a 1993 t/a. Questions - PY Online Forums

grd777 · #1 04-03-2021, 10:50 AM

Saw a very clean 93 t/a
Have some questions before a give a offer

1 owner said at idle the car overheats and then the fans kick in then it cools down.when it’s driving it is ok
2 when it was warming up I heard a ringing or jingling noise and then it went away
3 steering seem to be very stiff almost like it did not have p.s

What else should I check on this car

grd777 · #2 04-03-2021, 02:49 PM

Quote:

Originally Posted by grd777

Saw a very clean 93 t/a
Have some questions before a give a offer

1 owner said at idle the car overheats and then the fans kick in then it cools down.when it’s driving it is ok
2 when it was warming up I heard a ringing or jingling noise and then it went away
3 steering seem to be very stiff almost like it did not have p.s

What else should I check on this car

Also looking at. 2000 ws6

3tas4me · #3 06-11-2021, 06:50 PM

Quote:

Originally Posted by grd777

Also looking at. 2000 ws6

4th gens have a few maladies. All of them can have weak power window motors. The only repair is to replace the motor. Headlight gears can strip. The later cars (98 on up) get cracks in the door panels. The sail panels on the later cars can have bubbling which is caused by the glue they used on the panel. The top dash panel tends to crack if the car has been outside for a long time. You can still buy it new from GM but they are $$$$. The rear axle bump stops also disintegrate with time. Several choices from the aftermarket are available. I used a pair of third gen bump stops on my 1993. They bolt right in and are made of rubber.

The biggest issue with LT1 cars (1993-1997) is the Optispark distributor. I would recommend buying only a AC Delco distributor if you need to replace it. The LT1 cars use reverse cooling, no issue with overheating that I have seen. If a car runs hot, I would check to see if the cooling system has been properly flushed and maintained.

Good luck!

Sirrotica · #4 06-11-2021, 07:27 PM

Make sure the air dam is still in place under the front of car, people tend to hit them on parking stops, and rip them off, or remove them if they're hanging by a thread. If the front air dam is missing it will overheat.

Warren Seale · #5 06-13-2021, 09:53 AM

Quote:

Originally Posted by 3tas4me

4th gens have a few maladies.

The biggest issue with LT1 cars (1993-1997) is the Optispark distributor. I would recommend buying only a AC Delco distributor if you need to replace it. The LT1 cars use reverse cooling, no issue with overheating that I have seen. If a car runs hot, I would check to see if the cooling system has been properly flushed and maintained.

Good luck!

AC Delco Optisparks are rebuilt and most likely won't have the Mitsubishi optical sensor. All of the new sensors made today are knockoffs from China. The only new ones available are from aftermarket sellers and they will have the Chinese sensor.

grd777 · #6 08-22-2021, 10:00 AM

I did purchase a 1997 ws6 it is in excellent shape . Has small oil leaks that I want to fix. And sometimes it is hard to start will be asking question here soon

3tas4me · #7 09-24-2021, 10:49 PM

Quote:

Originally Posted by Warren Seale

AC Delco Optisparks are rebuilt and most likely won't have the Mitsubishi optical sensor. All of the new sensors made today are knockoffs from China. The only new ones available are from aftermarket sellers and they will have the Chinese sensor.

So, what is the best option if an opti needs to be replaced?

Warren Seale · #8 09-26-2021, 10:04 AM

I used an Optispark from AIP Electronics. They are pretty inexpensive but they are made in China so quality could be hit and miss. However, many have been happy with them including those with C4 Corvettes. There is also a guy that rebuilds them and he has extra Mitsubishi sensors that he uses in the rebuilds. He goes by the name of Optidoctor on the 4th gen forums.

He can be found on Ebay:

https://www.ebay.com/str/optidoctor

Also reference this:

https://ls1tech.com/forums/lt1-lt4-m...ble-today.html

3tas4me · #9 11-03-2021, 10:39 PM

Quote:

Originally Posted by Warren Seale

I used an Optispark from AIP Electronics. They are pretty inexpensive but they are made in China so quality could be hit and miss. However, many have been happy with them including those with C4 Corvettes. There is also a guy that rebuilds them and he has extra Mitsubishi sensors that he uses in the rebuilds. He goes by the name of Optidoctor on the 4th gen forums.

He can be found on Ebay:

https://www.ebay.com/str/optidoctor

Also reference this:

https://ls1tech.com/forums/lt1-lt4-m...ble-today.html

What is it that typically fails in the Opti? My '93 has 64k miles and I have had no Opti problems, even when the waterpump gaskets started to leak.

Warren Seale · #10 11-07-2021, 09:58 AM

Quote:

Originally Posted by 3tas4me

What is it that typically fails in the Opti? My '93 has 64k miles and I have had no Opti problems, even when the waterpump gaskets started to leak.

There are two areas that can fail. One is the high voltage side and the other is the signal control side. The high voltage side issues are the same as for any distributor and that is carbon tracking and excessive moisture causing the voltage to not make it to the spark plugs. The fix for this is to replace the rotor and distributor cap. The symptoms of failure are hard starting and misfiring just like with any standard distrubutor. The signal control issue is related to the optical sensor that monitors the crank/cam position and tells the ECM when to send the voltage to the distributor coil. Moisture is the killer for these although I've had two of them fail with no moisture issues. However, I believe in my case the issue was that the vacuum line that purges the air in the distributor was clogged and the stagnant air and high humidity year round in Florida caused the failure. If you have a 95 and newer LT1/LT4 it is important to make sure the vacuum line is functioning. There is a filter in the line that clogs over time. In your case there is no purge system so the moisture buildup tends to be more of a problem in these first generation Optisparks.

3tas4me · #11 01-01-2022, 11:56 AM

Quote:

Originally Posted by Warren Seale

There are two areas that can fail. One is the high voltage side and the other is the signal control side. The high voltage side issues are the same as for any distributor and that is carbon tracking and excessive moisture causing the voltage to not make it to the spark plugs. The fix for this is to replace the rotor and distributor cap. The symptoms of failure are hard starting and misfiring just like with any standard distrubutor. The signal control issue is related to the optical sensor that monitors the crank/cam position and tells the ECM when to send the voltage to the distributor coil. Moisture is the killer for these although I've had two of them fail with no moisture issues. However, I believe in my case the issue was that the vacuum line that purges the air in the distributor was clogged and the stagnant air and high humidity year round in Florida caused the failure. If you have a 95 and newer LT1/LT4 it is important to make sure the vacuum line is functioning. There is a filter in the line that clogs over time. In your case there is no purge system so the moisture buildup tends to be more of a problem in these first generation Optisparks.

So, are you saying my '93 would have more of a moisture problem since it isn't a vented cap?

I know that some people replace the Opti distributor with a coil on plug set up like the LS1 has.

tallrandyb · #12 01-01-2022, 04:29 PM

Quote:

Originally Posted by 3tas4me

So, are you saying my '93 would have more of a moisture problem since it isn't a vented cap?

I know that some people replace the Opti distributor with a coil on plug set up like the LS1 has.

Yes the non-vented optis have more problems with condensation/etc.

Also, for a 93 you will be running speed-density (no MAF sensor) and can only reprogram by replacing the chip. 1994 and later are EEPROMs and can be reprogrammed from a box (Hypertech/etc) or laptop. Big advantage if you are planning on doing significant mods to airflow/power.

I've replaced the function of the opti (still uses wheel and sensor for just crank position) but it really is a pain. Unless you go to the "full front LS1" conversion with LS1 computer you will be working with the classic LT1 computer and a Dynaspark to go to multi-coil but even then its 4 coils for 8 cylinders, not full coil-on-plug like LS engines.