My friends 89 firebird 2.8 has a no start glitch. It only happens sometimes. Like once or twice every 3 weeks or so. Waiting a few minutes to a few days allows it to start. The starter does not engage no solenoid click, just dash lights. He has been taking it to a pro mechanic, but they've never been able to get the problem to occur for them. They have tried cleaning oil out of the starter that accumulated in there from an oil leak. They have also tried bypassing that vats with a resistor. The last thing they did was remove a professionally installed alarm system. I am like his go to mechanic in a pinch, but I have not been able to look at the car during the no start condition. My friend (Lee) said that when he first got the car the exact same thing was happening and the shop he went to then removed his dist cap and replaced a small part and it never happened again for 15 years.

I'd like to just hard wire the starter enable relay to eliminate vats all together. I would also welcome any information on the part in the distributor. And any other help too.

Also what things should I look for if I can get to his car during a no start

 

The problem with hard-wiring the start relay is that it's not the only part of the VATS. There is a module that enables the start relay, and also sends a 5V square wave signal to the ECM. Bypassing the start relay will not eliminate VATS. The car will crank, but the injectors will not open unless the VATS module is sending the signal. However, if the start relay is the problem, bypassing it will, of course, allow the car to start.

Intermittent problems are never easy to diagnose, but there are ways. What I would do is temporarily install a test lamp at various points over time. I'd start at the 'trigger' terminal on the starter solenoid. When you turn the key to START, the lamp should light.

Now if you leave the lamp installed where the driver can see it, next time you have a failure, you will see that the lamp either lights up or doesn't. This will tell you whether or not there is voltage to the solenoid when you turn the key. If there is, then your problem is likely in the starter. If the lamp does not light when the key is turned, then your problem is further upstream. It may take a while, but eventually you should find a point where you have voltage when you turn the key, but no cranking. At that point, you can more easily pinpoint the source of your trouble.

 

I am aware of the injector enable feature. I had to hard wire my enable relay and install an injector enable module on my Bonneville. Fixed it right up. But since his starter is not turning over at all I can forget about that until it turns over. The characteristic start and run for 1 second would be easy to diagnose as the injector enable. The test lamp wiring sounds like a great idea. I'll bring it up with him. Starter solenoid trigger, starter relay output, Ignition (pink wire) and I'll look at the wiring diagram for other components in the loop. Thanks!!