JR36054

Alright for starters I'm jacob I'm new at this forum thing but I need some help.lol I have a 1994 f-150 xl 4.9L with single steel behind the axle tank and me and a friend just put a fuel pump in it and now we are getting power at the relay, power at the fuel pump fuse and no power at the inertia switch and no power at the fuel pump.. We have been working for two days trying to straighten out this problem any suggestions? We did take a wire from the hot side of the battery and hooked it in the inertia switch plug and got fire to the pump but no start..

JR36054

Alright now we have another problem we checked to see if the plug wires for a spark and no spark.We checked the coil we have power going in the coil none coming out so i went and got a coil and replaced it, now same thing.We took the ignition control module off so i can go have it tested is there anything else that would keep that truck from firing? I believe the next step is taking the ecm off and having it replaced..

Just call me Sean

iTrader: (1)

Did you happen to check the fuses?

JR36054

Checked every fuse and relay that I can find. Last resort was to replace the ecm and try that.

Just call me Sean

iTrader: (1)

It sounds like the computer isn't getting power.

JR36054

Ordered ecm last week suppose to be in thursday. I hope that fixes the problem.

hoytray

so what was the fix on this. I have the same problem

southernyankey1

3 year old thread...guess he figured it out!

see if the ecm will throw any codes. Check the TPS voltage..if it's bad nothing works!

hoytray

ecm! will do tps! I will have to look up what these things are and look like but I will do that. thanks

hoytray

so I checked this all out. I have not got voltage at fuel pump, I know this not only because I checked to hear if pump made noise when kicking on key, but also used a voltage meter to see if it had voltage at Key On, and also cranking. Went to inertia switch next, and checked for voltage when cranking and Key on, either way was Nope!. Next went to relay and use a jumper wire in 30&87 that fuel pump does work but inertia switch did not have voltage from the Red to Green wire but did from each wire to the ground; this was with jumper wire in 30&87. so this says it is not the relay. I went ahead and ohm tested relay and it ohmed 30&87a and 85&86. did this just cuz. anyways wouldn't you think the pump selector switch isn't the problem since in the schematic it comes after the inertia? I still checked it. Put Jumper in 30&87 and found voltage in there which show 12v between the center and either top or bottom then 7v between the two centers. Went back to relay again for fun and found the socket has 12v 30&86, 30&85, 30&87; not sure what to think now. pump only buzz's when jumper wire use but relay not bad???? what is it then? If this is just a ground wire then which and where can I find it? I looked at all the ground wire connections I could find. Help! it's a 1
94 4.9l duel tank 4X4