Need help, or I'm gonna get canned!!!

DangerangerHD · Mar 25, 2009

Truck sputtered at stop light
Drove it home wo a prob.
Next morning wouldnt start. No fuel to filter, relay clicks still, but not pump.
Buy pump off ebay.
Install. Drives around block fine.
Shut off. Wont start, no fuel to filter.
After a couple trys at starting works fine.
Drive for 1 day (slow to start but running fine).
Shut off.
Sleep.
Next morning, slow to start, stalls when starting off 1st gear, restart. tries to die. feather gas pedal.
Dead. wont start at all. No fuel to filter.
WTF?
What could be causing this? Is it a faulty pump? (bought off ebay w good seller rating) Or something else causing this sparatic fuel flow?

locovaca · Mar 25, 2009

Check your fuel cutoff safety switch. Could be going bad.

DangerangerHD · Mar 25, 2009

no luck with the inertia switch. I even opened it a couple times and reset it. Got a little fuel but just enough for the truck to start and sputter to death. now the pump isnt clicking on but the relay still is. Next step before chalking it up to the fp? I just want to know for sure before pulling the bed again.

locovaca · Mar 25, 2009

Bad wire? See if you can tap in with a multimeter and watch to make sure you're constantly getting power. I assume you have the bed off while testing all this, right?

DangerangerHD · Mar 25, 2009

I put the bed on after the pump replacement when it looked as if everything would work properly, Ahh, how naive.
So I just reset the fuel system (pull relay and start, then replace) and the pump kicked back on, truck tried starting but died shortly therafter I dont have a multimeter or test light, and wouldnt know what to do with them if I did. Anything else I can check for?

rurouni20xx · Mar 25, 2009

id really be looking at that fuel pump, but def start ohming wires and start looking for bad grounds or chaffed wires.

locovaca · Mar 25, 2009

Well, let's look at what you've done. You suspected the fuel pump, so you put a new one in. You now have the same symptoms. I would stop, for now, with the fuel pump and start looking at things upstream from the fuel pump (wiring, etc.). I know it's easy to blame the fuel pump, because that's something easily fixed/replaced, but if it were me, I would assume that two fuel pumps doing the same thing means that it's not the problem. It's a possibility, but it's a lesser possibility than some other things.</soapbox>

Going by an online repair manual, steps for diagnosing are:

1. Checking voltage at the connector
2. Checking inertia switch for continuity
3. Checking to make sure the connector is not loose or open at the fuel pump
4. Checking the relay by manually energizing it (grounding it)
5. Checking for plugged fuel lines

And if you're really into having fun, you might get a 5 gallon bucket, some hose, and trying to bench test the fuel pump to see if it's really the problem.

I know you said you don't have a multimeter nor how to use one, but if you want to fix problems like this by yourself, you're going to need to get and learn to use one, unfortunately. It's much cheaper than throwing parts at it...

ranger 93 · Mar 25, 2009

Dont forget to check your fuses and relay. My 93 did this and I had a fuse under the hood that had corrosion on it. I replaced it and worked fine. Just a thought!

DangerangerHD · Mar 26, 2009

Thanks everybody. Loco you are completely right Ive been putting this off for much to long. The internet can teach you almost anything and I'm sure something as simple as the use of a multimeter shouldnt be to hard to find. Viva google.

fastbluetruck · Mar 26, 2009

ogads man go to your local lowes or home depot and by a digital meter somewhere around 25 to 30 $$$ and then you can even check the wall sockets in the house with it. i dont leave home with out mine it stays in the truck with me

DangerangerHD · Mar 27, 2009

Ive got some connections at the local pawn shop, got a nice fluke for 8 bucks. Now how the fudge do I turn it on lol...

slimchriz · Mar 27, 2009

Do what loco said but I would replace your relay anyways when a relay goes bad sometimes it will switch on but shut off immeaditly after load is applied...it clicks so you think its workin but its not.

I had this on another vehicle pump went bad took relay with it replaced pump worked for a little while then die relay clicked but checked it with multi meter and confirmed it was not puting out under load.
last i checked there cheap so its good to have some extras on hand. or find a junk car and pull a bunch out.

for the multi...Find the model number type it into google and find a manual you can download...read manual. most have a dial turn it too DC in the 20 range

DangerangerHD · Mar 27, 2009

I dont think its the relay I switched it out with my eec and truck still dies after a few seconds. I turned on the ignition to run and start and pumps whining fine. Attached meter to leads that attach to the pump and got 11V at prime, 6.6V after Prime, and 10.3V while turning motor. Sound right or too low?

Earl43P · Mar 27, 2009

So, now the bad relay could be in the EEC relay position.
Just as much load, if not more AND that relay supplies the power to activate the Fuel Pump relay.

The PCM Power Diode is also in that circuit, so make sure it is in its socket tight. It's in the under hood box. Don't reverse its installed position.

It could also be your ignition switch.
Power gets routed when the key is in crank, but contact is broken and the Run position has no power to PCM or FP. Very likely scenario. Both my 93s had clapped out ignition switch linkages.

Earl43P · Mar 27, 2009

You really don't have to understand electricity to look for power.

Hell, 1/2 the time I use a homemade test light.

Take a 194 lamp.
Straighten its copper leads from the glass base.
twist a length of wire to each copper lead, solder and tape it so they can't touch. Skip the solder if necessary.
Take one of the leads and connect it to one of the inertia switch wires (You can just nick the insulation away and tape it later). PK/BK wire will tell you the inertia switch is good, along with relay. Touch the other lead to a ground (any bare metal). Anytime the FP has power, light is on. Simple. If the light is on, but the FP isn't running, either bad connection at top of tank or bad FP. Ground is good if your gas gage is accurate or the tail lights work. They share that ground.

Need help, or I'm gonna get canned!!!

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