no spark or fuel pumps

[Maglov12]

i have an 88 ford ranger 2.9l with no ignition spark or fuel pumps. ive replaced the eec relay, fuel pump relay, celinoid, both fuel pumps, distributor , distributor rotor and cap, TFI module. anyone know what else could b wrong?

 

[martin]

Sounds like you will have to do some point to point trouble shooting, Start by checking if you have power at the fuse box.

 

[Psychopete]

Start by checking if you have power at the fuse box.

Iirc he should have fuse links on the battery side of the starter solenoid. Don't think they started using the power distribution boxes until the Gen-IIs.

Run though this again (easier if you keep updates in one thread ) and it should help narrow down where the circuit is broken:

The wires are kind of similar, you should be able to figure out what is what with a volt meter -

My 1988 Ford Ranger/BII EVTM says:

Yellow wire is fused power for the relay and computer (pin #1) - hot.
Fuel pump fused power is also a yellow wire, but a completely different one with the same amperage fuse link - hot.

BK/LG is the computer relay ground.

R/LG is 12 volts from the ignition switch to the computer relay.

Red is power to the fuel pump relay switch side - hot when key is on.

T/LG is the computer relay ground switch side - this is what controls the fuel pumps. - Computer grounds, relay flows power to the pumps.

O/LB is to the fuel pumps - hot when computer grounds the fuel pump relay.



check if computer relay is getting fused power,
if it is, check the red wire for 12 volts on the fuel pump relay harness,

might also check if you're getting a signal from the ignition at the computer relay harness,

check the fused power for the fuel pump relay on the fuel pump harness that you have 12 volts,

check the computer relay ground,

There's a spot on the diagnostic connector that you can ground and supplement the T/LG that trips on the fuel pumps, but if you're not getting any spark, you problem is likely a fuse link, or maybe something with the computer relay (did the small ground connector get disconnected from the battery?).

 

[fyre82]

Really dumb question from me, but, have you checked the rollover switch under the glove box?

I had intermittent power loss problems and the end of a long, painful elimination that was the issue. I took it apart and weak contacts inside were the problem. Jump it out and see if that helps.

Good luck
Rich

 

[Maglov12]

inertia switch is the first thing i checked and it appears 2 be working fine. spark would have nothing 2 do with the switch so im thinking its not the problem. i have no under the hood fuse box so its not realy somthing ive looked into. i do have relays but 2 of the three have been replaced(fule pump relay and eec relay) not sure of what the third relay controls so i havent touched it. both yellow wires are getting 12v as well as the red wire with key on is getting 12v. i also did some poking around and i jumped the O/LB with the starter celanoid and the pumps wer running strong. still no sparks. not sure how 2 check the other wires like the ground and the signal from ignition to computer relay harness.

 

[Maglov12]

pumps run even with ke y not in ignition

 

[Maglov12]

so i went out just before dark and took out the computer in my truck. i got a buddy who is a high voltage electrician who said he would take a look at it 2marow for me. then i started messing with the truck a little and for some reason i figured id check for spark and now i have spark without the computer. i put the computer back in just to make sure somthing didnt just fall into place and become fixed and sure enough no spark. i took the computer out and tested it one more time just to make sure i wasnt seeing things and the spark is back. i still have no fuel pumps working but having spark again is giving me hope. does this mean the computer is bad???

 

[kimcrwbr1]

Did you check the eec relay I believe you will also get spark with the spout wire disconnected it takes the computer out of the loop to time it. You will not get any advance tho I would focus on the grounds tho and you can get a known good computer and try that also to see if it fixes the problem before you buy one. If you have a bone yard close you cand get one for cheap to swap out if the problem is the same it is probably not the computer no two computers will have the same problem going with odds.

 

[Maglov12]

i changed the eec relay with a brand new one so im not gana mess with somthing that i know for sure works. when getting another computer from junk yard do u need a truck with the same transmission and motor 2 make a computer swap? i found one that is the exact same as my truck but its an automatic and mine is manual. will it still work???

 

[Maglov12]

i also just finnish checking and cleaning any grounds i could find and still no luck.

 

[Maglov12]

so ii installed a new computer and everythings working perfectly. i got spark the fuel pump works great. i just cant get it started.

 

[Maglov12]

new computer fixed everything