1994 4.0 Wont start somtimes, driving me nuts!!!

[stuman7981]

I have a 1994 Ford Ranger 4x4 4.0 V-6 manual trans. Somtimes when I go to start it, it wont start. I cant hear the fuel pump run, let it sit for ten minutes and it will start. So I put in a new fuel pump and fuel pressure regulator. Did not help. I have power on one side of the fuel pump relay located in the small fuse/relay box under the hood. Took that box apart and cannot find any corroded/broke wires. This problems comes and goes. Might do it 3 times in a day and be good for a month. It will crank and crank and crank but not start, come back in like 20 min and it starts.Where does power come in to the relay from? Is there a ignition module on the steering column that could be bad? I am trying to trace power back from the relay but cant. Any help would be awesome. Both Ford dealers I talked to said they have never had this problem. I did check the relay switch and it is not tripped.

 

[blh0007]

hey man,
I had a very similar problem with my 94... i went the same direction you did replaced fuel pump, filter, the fuel regulator... I got a tip from another thread on this site... there is a relay under the hood for your engine control module... i replaced it and it hasn't failed me since. that was about a year or two ago, so i am assuming that it was the fix.

 

[stuman]

Where is that relay

I replaced the relay in the power distribution box and it did not help. Where is the relay for the pcm?

 

[Earl43P]

Right beside the green fuel pump relay is the brown PCM relay.

The PCM relay CONTROLS the fuel pump relay. If you don't have a Check Engine Light at the same time as when the fuel pump won't run (in Run before cranking), then the PCM relay is the problem. If you DO have a CEL, replace the FP relay.