My 89 GTA is not starting when hot. So I replaced the solenoid. Now the problem is even worse.

I ran the car for 30 min to heat it up then I measured the voltage across the solenoid when turning the key to start and it was 11.5V. The car would not start.

I ran a garden hose on the starter for 10 min to cool it down. The car then started. I pulled the distributer wire and turned over the starter while measuring the voltage across the solenoid switch. It was now 0 Volts.

Seems to me my problem is the solenoid? I read the tech article on the remote solenoid but I did not understand all the wires going to the new solenoid.

 

Check yout groung to the block and make sure the threads of the starter bolts are clean, maybe a dab of antisieze.

 

Is that little strap that goes from the solenoid to the starter motor properly attached? Are the rest of the wires properly attached? Good CLEAN connections?

 

Connections are clean, it's a new solenoid. Ground wires looked OK between battery/block and head/chassis.

This is my theory and the current battle plan:

I bought a cheap Neihoff solenoid. I think my start wire voltage going to the start terminal on the solenoid "S" is not 12.4 volts, more like 10-11V when the wire gets hot, they are routed from the firewall around the front of the engine and down to the starter. I think this solenoid is much more fussy about the voltage being too low to energize it.

When I turn the key to the start position there was 11.5 V between the "BAT" terminal and the starter post. Should be zero.

I am going to install a Ford solenoid on the strut tower area and run a new wire to the GM solenoid "BAT" terminal, and short the "BAT" and "S" terminals together. This should give it a full 12V when hot.

I will post results hopefully this is it.

 

Well, I installed a remote Ford-style solenoid on the strut tower and I didn't have any hot start problems today. It looks like my problem was caused by low voltage on the start pin of the stock solenoid.

I shorted the start and Battery pins together on the stock solenoid with a piece of metal. I drilled holes in it.
I then ran a new battery cable from the new solenoid to the stock solenoid. Here is a picture of the remote solenoid.