Intermittent non or Hard Start

[jester]

For several months I have had an intermittent starting problem. It started last fall and over the winter I did a bunch of work on the car including new EGR, plugs, wires, distributor cap, rotor, fuel pressure regulator, fuel filter, and MAF relays. The problem persists.

It seems to happen after the car has been running and is fully warmed up and then stopped for 1/2 to 1 hour. It is not the fuel injectors leaking. The fuel pressure does not drop at all in 1/2 hour after shutting the car down.

This weekend I have been able to capture two fail-to-starts with a scan tool. The only difference I see between a good start and a non-start is the fuel injector pulse width. On a good start the pulse width is 7.3 ms. On a hard or no start the pulse width is 5 ms or less.

This is on an '88 and the only non-stock item on this car is the Ford injectors. The problem did not start coincident with the injectors being installed. It started much later.
Is there anything other than the ECM that could cause the injector pulse width to shorten up like that in open loop start-up mode?

Sorry this post got a little long but I wanted to provide as much relevant detail as I could.

John

 

[WhalePirot]

Could the temperature sensor be malfunctioning? Certainly a warm engine needs less fuel to start.

Or, did you figure out the problem?

 

[redc4corvette]

Sounds like ECM or you need to clean the contacts or plug for the fuel pump?
they do get rusty.

 

[jester]

Thanks for responding. I replaced the EMC and it is starting good again.