I have been haveing starting problems all summer long,gets hot and doesn't start,cools off and starts like a champ, new starter,cables,heat blanket,alterinator checked, battery and still nothing worked, my girl friend works for a large gm dealer here in Phoenix and was telling her I had had it, she asked me if I had the battery checked, yes I had and then she got on her computer and said did I have an ac delco platinum battery? NO, she explained to me that my 89 roadster took a special ac delco platinum battery part #75p7y (7y is a 7 year battery) my cost is$78 and she also informed me that costco sells these batterys also. If anyone is haveing a similar starting problem you might look into one of these batterys.
:jester :jester :jester

 

Its a good battery, lots of CCA, but I doubt that it will cure your problem. I've told you before that you need to make some measurements when it won't start and find out what is causing the no crank when hot. You can keep replacing parts that are a logical cause until you finally fix it , but that sure is a dumb and expensive way to fix anything. Starter motor performance is degraded with increasing temperature and I'd prove that it is the starter motor temp by cooling it off rapidly and seeing if it will start. If that does it , then I would measure the starter temp when it stops cranking and see if that is a high enough temp to cause the starter to fail. If so, find the source of heat and get rid of it. All of us have block temps about 190 - 200 and an exhaust pipe running by the starter and we do not have this problem. If it isn't temperature, then it is increased electrical resistance of the connection from the battery to the starter. Compare the voltage at the starter terminals when it will start to the voltage when the starter won't crank, it should not fall below 9.0 volts. Measure the battery post voltage under the same two conditions. Instead of posting multiple times that it won't crank when hot, use that time to do some experiments to locate the cause. :cry

 

This last starter had a summit 1500 degree heat blanket put on it even before it was started the first time,cats are gutted so not so much heat here, I feel that this should of taken care of ALL heat problems on it, I already have a new positive cable running from the battery to the starter, crawled under the car this week to make sure negative ground was clean (what a bitch of a job) checked all grounds from chassie to motor all cleaned, some members of the forum have suggested that it might be the battery so im willing to try this, don't feel that its any other electrical problum, JFB, I do appreciate the impute but I think I have all bases covered, if you can think of anything I haven't covered please feel free to say so. TRAXX1

:jester :jester :jester

 

I do appreciate all the work that you have done so far, but.......I just cannot get through to you that you arrive fastest and cheapest to a solution to any problem by making measurements and comparing them to what is normal. For instance, you installed a heat blanket and the problem remained. This tells me that shielding the starter from external heat isn't the problem. For instance,
you installed a new positive cable to the starter and the problem remained. This tells me that the positive cable wasn't the problem. I do not have a problem with suspecting the battery as a cause, but if you will measure the battery post voltage when the starter will not crank, then you can eliminate spending $100 or so for a new battery if the voltage is the same as it is when you CAN crank the engine. The most critical measurement is the voltage that powers the starter motor and that occurs between the post connecting the start solenoid to the motor and the motor case. If it isn't at least 9.0 volts , then you need to find out where the voltage drop is in the path from the battery to the motor. If the voltage is the same , then it must be a motor temperature problem and you can prove this by measuring the starter motor temperature when it won't crank and/or put the garden hose on it to cool it
(heat blanket off if you have to) and see if it will crank. If you find yourself losing your cool, then walk away from the problem until you cool off. It requires logical thinking to find this problem and it helps to have the attitude that you are smarter than your car and you are going to design a test or measurement that will show what the cause is and anger is not going to be a component in finding the problem. If you exhaust all your knowledge, then find someone that has more knowledge such as a specialty car electrical shop that has a good reputation. Your problem is not insurmountable!