1993 LT1 stalling out, "NEED HELP!"
Thread Starter
Cruising
Joined: Jun 2013
Posts: 11
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1993 LT1 stalling out, "NEED HELP!"
My '93 Coupe stalls out when the temp gets to 195 degrees. This happens on the road or idling. I tried the usual suspects: #1 fuel filter, #2 fuel pump, #3 manifold map sensor, (this was a mistake, I thought it was the ignition control module), I left it in, #4 the real ICM, and #5 the coil. The car still stalls at 196 degrees. I'm at the end of my rope, and down $300.00......I know that there are many more things it could be. I'm trying to not go to a mechanic, because we all know what that could lead too. If you say codes, I guess I will have to go to a shop because I am not a decoder. Suggestions anyone??
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
If when you have it idling WITH a fuel pressure gauge attached to it....and it dies...and the fuel pressure is still where it was when the engine was running...it is not a fuel supply/pressure issue. IF it goes to 0 pressure...or really low...then it can be a fuel pump issue.
If you are at or past 70K miles...I would bet that it is in your OPTI-SPARK distributor. I recently repaired one with the same issue....and it was internally in the Opti-Spark distributor that was the problem. There is a specific test procedure that will directly identify if it is the Opti-spark. The test needs to be performed when the engine dies. Chances are also that the Ignition Control Module can be going out due to getting too hot...but once again...it needs to be tested when the engine will not start...or at least that is the way I test issue like this. I have a spare Opti-spark distributor that I use that can prove the problem very quickly along with a spark plug tester.
I am a mechanic...and like I tell my customers. "You do not have to do anything if you do not want to do. I am not trying to "sell" you anything or take you $$$$. All I am doing is telling you what is wrong. If you want me to fix it...great. If you don't...that is fine also...but I am still getting paid for the diagnostic and consulting time...which is more than fair."
So as long as the shop you take it to has a "clue" and knows how to read a book and perform correct diagnostics...you should not be too concerned. But get references first if you are not sure. Also...do not be cheap and looking at the cost of "things" all the time. Because if you install a cheap Opti-spark or cheap Ignition Module (for example) ...and NOT spend the money for the good ones ( I prefer GM/AC Delco personally)...and they fail...you will wish you had spent the money on a part that has lasted fora long, long time....versus an aftermarket parts that may or may not last as long...ESPECIALLY when you are half way to your vacation destination and the car is on the side of the road dead....and hopefully NOT in the middle of "No man's land".
The only time I do not use GM/AC Delco parts is when they are no longer available. If the customer wants to use a part other than GM/AC Delco...they have to buy it and they are liable for its performance...and it is something I DO NOT warranty. This is only because I have experienced the difference numerous times when aftermarket parts fail in over a year that my new customers had installed by someone else.
DUB
If you are at or past 70K miles...I would bet that it is in your OPTI-SPARK distributor. I recently repaired one with the same issue....and it was internally in the Opti-Spark distributor that was the problem. There is a specific test procedure that will directly identify if it is the Opti-spark. The test needs to be performed when the engine dies. Chances are also that the Ignition Control Module can be going out due to getting too hot...but once again...it needs to be tested when the engine will not start...or at least that is the way I test issue like this. I have a spare Opti-spark distributor that I use that can prove the problem very quickly along with a spark plug tester.
I am a mechanic...and like I tell my customers. "You do not have to do anything if you do not want to do. I am not trying to "sell" you anything or take you $$$$. All I am doing is telling you what is wrong. If you want me to fix it...great. If you don't...that is fine also...but I am still getting paid for the diagnostic and consulting time...which is more than fair."
So as long as the shop you take it to has a "clue" and knows how to read a book and perform correct diagnostics...you should not be too concerned. But get references first if you are not sure. Also...do not be cheap and looking at the cost of "things" all the time. Because if you install a cheap Opti-spark or cheap Ignition Module (for example) ...and NOT spend the money for the good ones ( I prefer GM/AC Delco personally)...and they fail...you will wish you had spent the money on a part that has lasted fora long, long time....versus an aftermarket parts that may or may not last as long...ESPECIALLY when you are half way to your vacation destination and the car is on the side of the road dead....and hopefully NOT in the middle of "No man's land".
The only time I do not use GM/AC Delco parts is when they are no longer available. If the customer wants to use a part other than GM/AC Delco...they have to buy it and they are liable for its performance...and it is something I DO NOT warranty. This is only because I have experienced the difference numerous times when aftermarket parts fail in over a year that my new customers had installed by someone else.
DUB
A failing opti may not set a code.
