I have a stock 1988 Camaro IROC 305 TBI.

I have had the car for a year and I have always had trouble starting it when the engine temperature is above 70 celcius, the hotter the engine the worse the starting, if at 105 celcius (when the fans kick in) I am lucky to start it at all.
The engine just cranks over painfully slowly (like I said above, the hotter the slower)
Sometimes when I do get it started the idle speed cant get itself above 450-500 rpm (usually idles at 750-800 rpm) until I tap on the gas pedal, then it returns to the normal rpm.

I believe that too far advanced timing can cause this, I would like to check to see if this is the problem and I wondered if pulling off the main lead into the centre of the distributor would harm the system. I only intend on doing this when the engine is hot when the problem is occuring, my thinking is to stop the sparking to all cylinders by pulling the main plug and then try starting it to see if the engine will crank over normally (by stopping the premature ignition)

My main question here is will pulling that plug off and trying to start the engine cause any electrical problems or electrical overloading, also is this a good idea overall? I just dont want to go to the effort of loosening and turning my distributor and finding out its not the problem.

I would appreciate any comments, thanks.

 

That is a valid diagnostic procedure, and won't harm anything provided that you shunt the coil lead to a good engine ground. Simply removing the HT lead from the ignition coil and allowing it to dangle will cause the ignition system to generate the highest voltage it can produce, straining all components and possibly causing damage. Ground the coil secondary lead, then crank away.

If the engine cranks at normal speed in this manner, you may have a timing and/or compression issue. This is not that uncommon, and can indicate a problem with the base timing setting or EST function.

If the symptoms remain the same, you may have a starter that is failing due to insulation breakdown under heat stress (also not uncommon).

 

Thanks for that info, I have considered starter heat problems and corroded connections etc. I will do the timing check that i mentioned earlier as that seems to be the simplest procedure for testing initially.
I'll put up a post if I cure the problem. Thanks again

 

No, pulling the central HT lead did nothing, problem still there.
Must be an electrical fault or starter problems.

Thanks anyway

 

Dirty/corroded/old and grungy/oxidized ground from batt. to block (@ block), or you may have a slightly loose pos. wire to the starter.