I replaced the turn signal switch on 1988 f150 and now it wont start. i have spark but fuel pump not running. the truck ran when i parked it to replace the switch. i also snugged up the bolts in the valve cover. checked around to be sure i didnt pull any wires off. theres a green wire hanging there but dont see where it goes. may have been that way when i bout the truck a few weeks ago.
You said you hear the pump come on, then said fuel pump not running ???
Check the fuse for the pump, preferably with a test light to verify power is there. Key must be in on position. If the fuse is powered, feel for the fuel pump relay to click when you turn key to on. Put your finger on it while someone turns key to on. If it clicks, check for power at the tank connector on the pump wire, while the engine is cranked. If power there when cranking, the pump must have failed and needs replacing. If the relay clicked with key on, and no power at the pump wire at tank while cranking, then check wiring from relay to pump connector-the fuel wire may have broken.
If the relay doesn't click when key turned on, check for the power feed for the pump at the relay terminal. If the relay has power available to be transmitted to pump, then the relay's signal from the computer or the ground side of the relay's coil signal (from the computer) may need checked.
If the pump is working, and you have good pressure in the lines, check the injector circuit. Also a fused circuit, so check the fuse first. The injector should have a steady voltage signal to it with key on. The injector only has two wires, the power wire and the ground wire which goes to the computer. When the computer momentarily grounds the injector circuit, the injector "pulses", causing fuel to spray out the bottom.
Straight wired fuel pump and it works. Relay does not click when key is switched on. I checked power to relay and 2 wires have 12v and 1 has .75 v with key in on position.
Straight wired fuel pump and it works. Relay does not click when key is switched on. I checked power to relay and 2 wires have 12v and 1 has .75 v with key in on position.
Straight wired fuel pump and it works. Relay does not click when key is switched on. I checked power to relay and 2 wires have 12v and 1 has .75 v with key in on position. What color are the wires to the EGR vacuum regulator? One is missing and can find a hanging wire anywhere.
Jumped hot wire at relay plug to pump and it comes on. When I plug in the relay it doesn't click. Computer?
Ok this is freaking weird. I'm sitting in the truck thinking and noticed the blue illuminated ac button was on so I pushed it off and the fuel pump shut off. Push it on and the fuel pump came back on. I'm lost. No telling what kind of rigged up mess that guy I bout the truck from has done.
Was that an aha moment? So he rigged that up to turn the pump on...pretty resourceful hillbilly, lol, speaking as one myself. Your right, though, no telling what else. Just a thought: you might find an engine wiring harness on the internet for cheap. Where you go from here depends on how you value the truck. If it was mine, I would like an enlarged copy, no two of them, of the complete wiring diagram, and just keep one in the truck, you know.. It may be a necessary reference tool in your truck. Keep posting your progress. I swear I'll never buy another chilton manual. Last one was for a sentra and not a complete diagram, not enough year specific stuff. Very disapointed with chiltons the last several years. If you can afford it, go for the factory service manual. That's where chilton and others edit their stuff from, I think.
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SOURCE: no power to fuel pump or fuel pump wiring harness...
try the electrical ignition switch on the steering wheel colum
SOURCE: 1988 F150 wont start
Check the positive side of the battery for a burnt fusible link. It looks like a wire but when it's over loaded if burns in half. Look at the pos. battery side of the starter solonoid you'll see a few of them there. Check your ignition module as well. This controls the coil and distributor and is mounted to the driver side inner fender.
SOURCE: 1994 f150 no fire to coil or fuel pump
i got a 1994 f150 that starts but cuts right back off so i had no fuel psi so i put a new fuel pump and fillter then found out that it was not getting power to the pump the cut off is not triped and no brakes in the wires can anyone help??
SOURCE: fuel pump still not working
I had the same proplem, remove spare tire and on the crossmember above it,left side, there is a fuel pump drive module. Mine was corroded and got moister in it .replaced it and runs fine. dealer price 110.00 dollors
SOURCE: i am not getting power to my fuel pump
on a lot of ford products there is a switch that goes from the fuel pump to the inside of one of the bedsides.
what this is, is a shock switch that turns the fuel pump off if it absorbs a hit.
its a really dumb safety feature but its effective.
there is a red button on it that u have to press to make it active again.
sometimes they just trip for no reason.
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i also replace the ignition control module. fuel pump relay and eec relay. nothing worked
typo. i cannot hear the pump come on
i believe i have an inline pump. ill check tomorrow. testing power to wires is a weak link for me. i get seriously confused. lol ill give it a try though
Here's how to check fuses with a testlight: Ground the tester to a good ground, any metal bracket or bolt, and probe the top of fuse where the indents are-one on eack side of top of fuse-turn key to on and see if tester lights up-it should light the test light on both sides of fuse-that's a good fuse, but if testlight only lights on one side of fuse, that's a blown fuse. Using a test light to check fuses is easy, don't have to pull fuse out to check if good. When key is on all your fuses should be showing power on both sides of fuse-every fuse is powered when key is on.
Ue the test light also to check relay terminals, and to check the pump wire at the pump connector. Make sure the test light is grounded good when checking-may have to clean off a metal piece under there where the pump is.
i ran all of these test.http://easyautodiagnostics.com/ford/rela... the relay is not clicking to send power to the fuel pump. red and yellow wires have 12v power. i jumped the tan and brown wire and no current in going through. ive rplaced the relay with 2 different new relays. still no clicking of the relay. my original relay has 4 prongs and the other 2 from advance auto parts and oreillys has 5 prongs. the guy say thats the only relay listed for my truck. im lost. only other thing i can think of is the computer.
update. I was checking fuses and remembered i took out a fuse for the heater/ac. well i replaced it and now the fuel pump comes on and the relay is clicking. whoever had this truck before me has stuff screwed up. the fuel pump runs non stop. i read somewhere that is this happens that the computer is bad. also it still wont start but is getting fuel. ill check the spark when my son gets home from school
Yes, could be computer. But since you don't know for sure, rather than buy a new one, I would check salvage yards for a used one to try. Looks like you will be needing a wiring diagram, bill. Good luck.
no spark from coil check ign module for power and ground. all good. i just dont get it. i changed the turn signal switch now all this
Check the coil primary for voltage with key on. If you have a voltmetet/ohmmeter, check the coil's resistance between the pos. and neg. small terminals-should be "around" 2 ohms. also check resistance between the neg. terminal and the coil high tower-should be "around" 10,000 ohms. If way off on these ohms values, try a new coil...or just try a known good coil-if you have voltage to the coil pos. terminal with key on. If no voltage to coil, check wiring from ignition switch to coil.
i ran the ign coil test from here.http://troubleshootmyvehicle.com/ford/4.... and on test 4 it say the the test light should flash when cranking the engine. mine isnt flashing, it has continuous power as soon as i turn the key on. any ideas on the problem?
If coil has voltage to it with key on, could be a bad coil, a bad ignition module, or possibly a bad pick-up coil inside the dist.-the pick-up coil; tells the computer crankshaft position, so it knows when to time the spark from the coil.
ign coil and ign module are new.
Kind of pointing to the computer, doesn't it? I don't know if there is a way to really test them. Most references I remember were to try a known good one and see if it worked. You might want to check out the pick-up coil, if that's what it is inside the distributor.
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