PCM relay 1993 explorer

[68fastback]

Anyone know where it is and how to check/change it. I've checked the inertia switch, replaced fuel pump relay and replaced fuel filter. My explorer starts and runs fine for couple minutes then dies. Cannot be started again for some time then does same thing. I'm headed toward replacing the fuel pump at this point and I read a post about checking the PCM relay first.

 

[MrShorty]

On a real basic level, relays are merely switches. So you test a relay by determining if the relay is closed when it should be an open when it should be. In the case of the PCM relay, it should be closed whenever the ignition switch is "on". A wiring diagram will help you see how it is wired in (even the diagrams in Chiltons or Haynes should be adequate), probe the red wire coming out of the relay with a voltmeter, then turn the key on and see what voltage you see. If you see anything other than ~12 V, then there is something wrong, and you take further action to determine if it is the relay itself or some other fault.

As far as other diagnosis for the stall/no start. I might pull codes from the computer (some situations like this will leave clues in the computter). I would probably also hook up a fuel pressure gauge to see what fuel delivery is doing (this could also help determine if the fuel pump is at fault before you replace it).

 

[YBCold]

do you mean the EEC Relay?

the EEC relay is under the EEC fuse in the engine compartment. sometimes they stick open or shut.

heres a link to get it out its the same as the fuel pump relay.

http://www.explorerforum.com/forums/showthread.php?p=2171512#post2171512