No start when hot

Yes, I have seen this problem before when the leak detection pump shorts out it will pull the signal from the computer not allowing the starter to engage. To be sure unplug the pump and see if the starter works?

Here is the pump location.

This guide can help as well

https://www.2carpros.com/articles/car-cranks-but-wont-start

Check out the diagrams (below). Please let us know what happens.

Cheers

It is between the vacuum canister and the purge valve under the van. It pressurizes the system for the PCM to check for leaks. Here is the oem part number 4891416AD. You will find it on the internet. I disconnect the electrical connector from the LDP (leak detection pump) and the chattering stops. My only thought is that the car should still start with the bad LDP, but it does not.

The electrical system is charging properly. If you leave the key on long enough, the chattering stops and the car will start. Is something else holding the circuit open? When the chattering stops, you here a relay close up by the fuse box. There are only two types of relays in the fuse box, so I rotated them all 1 position to rule out a bad relay. Thanks for any more info you can give me.

If disconnecting the LDP pump connector stops the chattering sound, then there is probably a defect related to that circuit which is putting an excessively heavy electrical load on the battery. It could be a bad pump or it could be a defect in the wiring harness (such as damaged or pinched wires). Have you tried leaving the pump disconnected to see if the starting problem disappears? That is probably not a long term fix, but it could be a good method to isolate the fault.

Thanks for getting back to me. Disconnecting the LDP does not solve the starting problem. I actually took the pump out and put it in my sons van, (he has the same year and model) and he had no problems at all. I tested the crankshaft sensor and the camshaft sensor to see if they were shorting out, because they could send the wrong signal to the PCM and cause it not to crank, but they are good. I tested all my power points and grounds for the sensors and PCM, they were good. I even tried to jump the starter at the solenoid when this is happening, and the starter will crank but the engine will not start. When I disconnect the harnesses from the PCM the noise stops. It seems that everything is pointing to the PCM, and the problem is getting worse. I called around about the PCM and no one here in Houston has one. They said they are that prone to failure and they sell quickly. My son had to have his replaced at 60,000, but it was still under warranty. I think I am going to order one on the internet, but I am leary about not knowing the reputation of some of the re-builders. Does it sound like it could be the PCM to you? I appreciate all your effort.

Yes, it does sounds like the PCM is bad. Below is the location try to get a used one.

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

Cheers

I got a used PCM and the van has never run better! Thanks for hanging in there with me. I love this site.

Use 2CarPros anytime, we are here to help. Please tell a friend.

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