Have a 2001 Trans Am that has been having this issue on and off for a few years now, I don't drive it daily. Basically I can let the car sit for a month (on a battery tender of course) and it will fire up no issues. I can take it for a drive, turn it off, go into the store, and turn it back on it no issues either. When the car is warm however if I turn it off and then try to start it up again just a few minutes later, it will crank and crank but not start. I can put it on a jump starter and it makes no difference either. Have even replaced with a brand new battery. The fuel pump is running, pressure on the rail is normal, I've replaced the starter relay, replaced the fuel filter, and the issue persists. If I wait 10 or so minutes, it'll just start right up again. Any clues on what could be causing this? I've searched the forums extensively.

 

Have you tried a dab of starting fluid during this condition? It would eliminate fuel being the culprit if it fired up.

 

i had a similar issue and replaced the entire fuel pump module from the tank with a new one from delphi. solved all my issues.

 

My 2002 WS6 started doing this earlier this summer (its still summer in Houston!) I only drive the car about once a week and today was a driving day. I parked the car at the dentist office and 1 1/2 hrs later, I tried to start the car. I cranked and cranked for several seconds but the engine wouldn't start. I turned the key to the off position, waited one or two seconds and tried again. The engine started right up and I drove to the voting place to vote. Voted, came out and the car started right up. Went to the Chinese buffet. An hour later, the car started right up.

I haven't done any trouble shooting but maybe bigsticksupra's post above is what will fix my car. Rockauto carries Delphi and genuine GM fuel pump modules.

 

Since my fuel pump is the original, I may replace mine as well. Have debated between OEM or upgrading to the Walbro 255 or a Racetronix kit, car is mostly stock but prices seem similar. I’m in Austin, so pretty similar temperature situations.

 

Among all this, I tried to do some relay checks to troubleshoot. I removed the ignition relay to see if it would replicate the issue in the event the relay was failing when hot, and the car actually started without an ignition relay. Is it supposed to do that? Next I put the ignition relay and removed the starter relay, and again it started. I did not try starting with both of these removed. Is that normal behavior or is something up?

edit: my relay box covers are likely swapped and thus I’m troubleshooting the wrong relay entirely (fan instead of ignition).

 

No damn way the car started with the Starter Relay removed because that is what completes the circuit to the Starter.

My vote is a Crank Sensor on the way out and wondering why I'm the first one to think of it.

 

It doesn’t make sense to me either, I wanted to make sure I wasn’t crazy. I think you just clued me into a possible causation though, since this is happening I suspect my relay box lids are flipped and thus my diagrams are wrong and I’m pulling what I think is the ignition or starter relay and it’s actually the fan relays 🤦‍♂️. If this is the case, I should probably replace my actual ignition relay as a first step then?

 

I said Crank Sensor for a reason..

 

Maybe this is what I need as well.

 

I've fixed many this way, bad Crank Sensor gets hot and the circuit inside it breaks connection.

If the engine is turning over with the Starter then everything electronic is good with that circuit so there's no need to start replacing Relays. Little intuitive thought goes a long ways.

PCM is not sending the fire signal to the Coils. Crank Sensor is what initiates that.

 

This makes perfect sense.

 

Would I be getting a code or CEL if the crank sensor was the cause or not necessarily?

 

Not all the time. Car won't start.

 

Starting with the cheapest and simplest option since I realized my relay labels were mixed. I swapped my relay box covers back to the correct location and went to my actual ignition relay, noticing that it is the original relay from 2001. The car starts 100% of the time when the car is cold, so I removed this relay and got the same scenario I get sometimes when the car is hot: cranks and cranks but won't start, so removing the relay seemed to recreate this scenario accurately. I put a new relay in and it immediately started. I will drive the car a bit and see if this fixes it.

 

If your symptoms persist try pulling a plug wire and check for spark while someone cranks it.

 

Took it out for a drive today with multiple stops. Zero issues this time, I think replacing the ignition relay (which was still the original one from 2001) did the trick. Hope this helps others.