reno

Ok, my son has this truck and did a oil change and spark plug change on it. Now it will not start up and run on its own free will. If I spray ether in the plenum then it will run, and if i continue to pump the throttle (easily) it will continue to run, but not much power. I think a complete tuneup (wire set and cap/rotor) is needed, but the little voice in the back of my head says ......fuel pump. His gas gauge does not work, along with a few other things since the previous owner lent out the truck and when he went to get it back, his sisters kids cut a few wires(ignition to the starter solenoid is all I know), but we were going to check the level in the tank this weekend any ways. I will do a fuel pump pressure test, I hear the pump turn on, but do not know the pressure. We added 2 gal gas to it as well, but maybe there still is not enough fuel?
Any one here experience this before? Am I missing something, so I don't have a goose chase. Thanx! Reno

87f-150

Fuel pressure would be the first thing i would check.

reno

Ok, put new wires/cap & rotor on. Still no start. Went underneath and found out the pump in the tank is a low pressure and the high pressure pump seems to have been replaced once before. The shield was not properly done, this joker even jury rigged the wiring. The ground will fall off with a breeze because the female connector is to big. The hot side does not even have a connector, instead he trimmed the wire, pushed it through the small hole on the pumps male connector and bent it around the blade with nothing else. Intermittent problem solved. I found the resivor leaking (the part behind the high pump that changes between the two tanks for fuel) very little gasoline, but a leak is a leak. Anyone know how to eliminate this? We don't use the back tank. Anyways, fuel pressure test...key on:42psi then immediately drops to about 5psi, turn key off drops to zero, will not hold pressure, looses to fast for that small leak. Possible high pump bad? Truck starts without starting fluid now, but will not idle on its own, have to keep feathering the gas. Thank you

reno

Btw, I made s better temporary connection with the +/- of the high out pump.

87f-150

First sound like high pressure pump is bad at 42 psi. It should be 50 to 60 at key on
And with engine running 40 to 50 psi. Then when you cut it off it should hold pressure
Not drop. I would replace the pump and then fix the wiring for the pump .. if it were me
I would also just replace the switching valve that is leaking you might need to use the back
Tank one day.

reno

New pump installed and wired with connectors. Fixed leak from the resivor, bad o ring. Pump test 45psi key on, 32 -36 psi engine running. I think the IAC needs to be cleaned or replaced, hard idle at first, then idles. Check engine light came on, things get strange here....pulled codes koeo....63,65,85. None of these belong to this truck. 85- clutch switch..Auto tranny in truck. 65-63- fuel pump (diesel), gasoline engine. When I went to do a koer test, test would not go, nothing from tester. I have two OBD1 Testers, both did the same, like they were not connected. Can not erase codes either. Bad ground to EEC? May the truck has been in limp mode, maybe just so happenly started this now? Truck runs great. Now have to figure out the EEC. Any one have issues like this before?...with the EEC test on KOER?

87f-150

Did you unhook the neg cable off the battery and wait 5mins then drive it and recheck
For codes?

reno

No I did not unplug the neg cable. Once I tried to pull codes for the now check engine light that came on. On my testers, they are both Innova's one is a OBDI\II and the other is only a OBDI. I tried to clear the codes, it appears to have cleared, but in reality never did. On the more expensive Innova, it is model 3140 you just press the erase button, it asks you if you really want to erase the memory, click ok, then all memory codes are gone.

-=RENO=-

reno

On a side note, when the engine is cold, it will not idle, if the pedal is not held to maintain 1,000rpm, until warm, it stalls. Driving and take offs are not a problem either. Took the iac off, turn key on and the rod moves easily, no carbon buildup. What should we look for?

87f-150

You have to take the neg cable off the battery to reset the computer and clear all codes
By doing this the computer relearns the idle after about 10 to 15 miles it gets it out of that
limp mode. Then you have a better picture on how its ildeing over all.