Intermittently operational fuel pump

[jeepalyn]

Fuel pump doesn’t always come on; sometimes it does and sometimes it doesn’t. The fuel pump, ignition control module, and one of the relays have been replaced. Not sure what else it could be. Thoughts?

 

I'm a newbie and not all that well versed in things mechanical, so any clear feedback on this would be much appreciated. I'm trying to do everything I can before I take it to a shop.

[Eagle]

What are the symptoms when it doesn't come on? Does it die when running, or not start, or ...?

[jeepalyn]

Generally it cranks but won't start. It has died in the middle of driving. Put in the ignition control module today, it started on the second try and drove fine during a short test drive. After the drive it would not turn back on, even after sitting for a while (30 minutes....then, tried it again four hours later).

[Tommy]

Check grounds? Left tail light ground, refresh?

[Eagle]

If it's a 1988 or newer, try bypassing the ballast resistor.

[Brickmiata]

Definitely start by checking over and refreshing the entire fuel pump circuit.  Based on what I found when I did this, I was surprised mine ever started and ran.

[Incommando]

I know this may sound simple and be something that you have already thought of  but to make sure it is the fuel pump on a no-start you can try turning your key to run before starting. Listen for the little 1-second long buzzing sound of the fuel pump firing up and then turn the key to start. No buzz = no fuel pump. It also seems to shorten your cranking time a tad, as well.

 

Got in this habit when I was driving a '93 CTD Dodge as you have to turn the key and wait for the light to come on before starting it. After 12 years and 230,000 miles of doing that it has stuck. Hearing the fuel pump was something I just noticed while I was doing this in my other cars.

[cruiser54]

Move all the relays down one position and see what happens.