94 Explorer Start Issue - Fuel Pump Relay?
#1
94 Explorer Start Issue - Fuel Pump Relay?
Sometimes after running my 94 Limited, it doesn't want to start - it does crank - like it's not getting fuel. I have found the work around and want to know if it would be fixed by replacing the fuel pump relay.
The symptom is just after starting, it starts to run poorly, and then dies out, then will not start at all. I use to keep trying to start it for 20-40 minutes and suddenly it seemed to work.
It seems the work around is to turn the key to on for about 5 seconds and then turn it off - then "wala", it starts and runs as good as ever.
So, is this a symptom of a bad relay? I thought I'd start there because of the cost of the relay is fairly cheap. Anyone else having/had a similar issue with their 94 Exploder Limited 4x4?
The symptom is just after starting, it starts to run poorly, and then dies out, then will not start at all. I use to keep trying to start it for 20-40 minutes and suddenly it seemed to work.
It seems the work around is to turn the key to on for about 5 seconds and then turn it off - then "wala", it starts and runs as good as ever.
So, is this a symptom of a bad relay? I thought I'd start there because of the cost of the relay is fairly cheap. Anyone else having/had a similar issue with their 94 Exploder Limited 4x4?
#3
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#7
Ya know, if you keep the door open when you turn the key, you can hear the pump prime for the second or two. And to think of all the times I just set and tried to start it for 30 minutes. Of course, I've put a little too much wear on the starter and flywheel now because of this.
Oh well, at least it still starting.
Oh well, at least it still starting.
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#8
94 Explorer...fuel pupmp relay ???...no start.
I have been on several sites and see this issue is very common with the Explorer. For years now Low voltage, high resistance, cheesy fuel pumps, (one guy)4 pumps in 5 years time,(ME, one fuel pump so far), one throttle position switch, and on and on and on. Some people spend many hundreds, even thousands of dollars on this problem, only to find out nothing has changed. FMC could weigh in and save us all from our limited infrastructure and limited knowledge of the things ford already knows about this problem. Mean while I think I'll restart my repair(?) with a $15.00 relay. Thanks Ford, I'm looking at Toyota as a permanent fix for this problem. My efforts at getting rid of the,"I'll start when I'm ready, problem", has been with me for 4 years now. Months may pass, runs fine, starts every time, then, "cranking good, no start"..., fuel pump silent. GM, already doesn't sell cars to me..., but not for wanting to.
#9
bfc4, is onto something... "Open the drivers door and see if the fuel pump comes on" before cranking the engine. This should be done every time you start a car to allow the fuel pressure to come up and provide good initial fuel for starting. Silent fuel pump? Increase the voltage to the system, via jumper cables or a charger. As soon as "I" do this, the fuel pump comes on, and the engine starts perfectly smooth. Yes it is a voltage issue (to the fuel pump) but it only shows up as a fuel pump issue.always always cranks fine. I am not at all convinced that I, or many others, have the answer by swapping out relays and or other more expensive parts. If THIS relay swap works I'll let all of you know, but first the big test of the system.
#10
Still starting since 2007
Well, I just checked and it was September "2007" when I put in the relay. Fingers crossed, nary one starting problem since. My "Exploder" is my go to vehicle. I now laugh at the tax value; I'm glad they don't factor the value to me! Start simple... Open the door, listen and buy relay if it cranks and won't start. A cheap n easy test and your flywheel and starter will love you.
#11
I had an intermittent no-start issue with my 94 Explorer. Every time it wouldn't start, I couldn't hear the fuel pump turning on. So, I initially thought fuel pump or fuel pump relay. I removed the relay and probed some wires into the fuse box where the relay plugs into. I basically "hot-wired" the fuel pump directly to the battery. The fuel pump would always turn on when I did this. I plug the relay back in, and it wouldn't start. So, I knew the pump and all the wiring going to it was good, and that it must be the relay. I replaced the relay and it still wouldn't start.
Well, long story short, after a lot of troubleshooting, staring at wiring schematics, and hacking up some of my wiring, I discovered the problem was actually the ECM relay, not the fuel pump relay. The fuel pump relay grounds through the ECM (that's why when you turn the ignition on, but don't start the engine, the fuel pump turns on for a few seconds and then turns off. The ECM makes it turn off after a few seconds.)
I thought I had finally narrowed it down to a bad ECM, so I bought a new one. As soon as I installed it, the truck still wouldn't start. At some point after that, it finally dawned on me that there's a relay for the ECM. I replaced the ECM relay and the problem has been gone ever since.
So, the problem was the ECM relay was bad, so that prevented the ECM from turning on. Since the ECM was not turning on, the fuel pump relay was not getting grounded and wouldn't let the fuel pump turn on, which is easy to mistake for a bad fuel pump or fuel pump relay.
So if you're having a no-start issue where the fuel pump is not turning on when you turn the ignition on, you need to make sure BOTH the ECM relay AND the fuel pump relay are good. If either one is bad, you will get the same symptoms.
Well, long story short, after a lot of troubleshooting, staring at wiring schematics, and hacking up some of my wiring, I discovered the problem was actually the ECM relay, not the fuel pump relay. The fuel pump relay grounds through the ECM (that's why when you turn the ignition on, but don't start the engine, the fuel pump turns on for a few seconds and then turns off. The ECM makes it turn off after a few seconds.)
I thought I had finally narrowed it down to a bad ECM, so I bought a new one. As soon as I installed it, the truck still wouldn't start. At some point after that, it finally dawned on me that there's a relay for the ECM. I replaced the ECM relay and the problem has been gone ever since.
So, the problem was the ECM relay was bad, so that prevented the ECM from turning on. Since the ECM was not turning on, the fuel pump relay was not getting grounded and wouldn't let the fuel pump turn on, which is easy to mistake for a bad fuel pump or fuel pump relay.
So if you're having a no-start issue where the fuel pump is not turning on when you turn the ignition on, you need to make sure BOTH the ECM relay AND the fuel pump relay are good. If either one is bad, you will get the same symptoms.
#12
#13
FIXED - Intermittent start Issue
94 Explorer - Eddie Bauer
Replaced:
Starter
Module (Not Ignition Module)
Had intermittent starts, every time i backed the truck up at work it wouldnt start when i left for home. After i got it towed it always started right up... i initially thought fuel pump was maybe getting bumped around enough to fire but was just getting cold after sitting outside in the country. The computer read Ignition Control Module or Crank sensor but i didnt get either replaced as i thought it was a wire between fuel relay and pump. Relay was good. Recently the car sputtered on me and cut off ehile driving, i had it pulled instead of towed and we traced it back to the COMPUTER where there was a frayed brown wire. Hope that helps! Seems no one has ever posted an answer for this... God Bless
Replaced:
Starter
Module (Not Ignition Module)
Had intermittent starts, every time i backed the truck up at work it wouldnt start when i left for home. After i got it towed it always started right up... i initially thought fuel pump was maybe getting bumped around enough to fire but was just getting cold after sitting outside in the country. The computer read Ignition Control Module or Crank sensor but i didnt get either replaced as i thought it was a wire between fuel relay and pump. Relay was good. Recently the car sputtered on me and cut off ehile driving, i had it pulled instead of towed and we traced it back to the COMPUTER where there was a frayed brown wire. Hope that helps! Seems no one has ever posted an answer for this... God Bless
#14
yep.. start simple.
Thanks all for the info. I learned.. relearned..to keep it simple first when trouble shooting. Relays are notorious. My ECM relay hasn't failed but it might had already been replaced. I read somewhere the fuel pump kicks in to prime the line before starting. I didn't know that was an ECM function, but makes sense. While some of the LTD bells/whistles are failing (like window leak killing the alarm computer) I can't imagine letting go of my "Ploder". Off with it today to get the XMAS tree as with many years before. Merry Christmas guys (and gals) !!
#15
Having sorta the same issue
Right now the issue i'm having is the truck starts, but sometimes runs with a really low variable idle (bogs down to 500rpm, then upwards of 900rpm), it makes the engine/whole car shake when it gets really low, sounds like its going to die, and the battery voltage meter fluctuates, sometimes it will die, sometimes it will 'catch' and all the sudden level out to about 900 RPM idle, battery meter returns to normal, everything just levels out. When this happens though, where it 'bogs down', when i push the gas im getting absolutely nothing, will not rev even slightly, only after it 'catches' can i rev the engine.
dont remember this happening before my alternator went out, I had to drive it to the junkyard to pull one out of another '94 explorer, but getting there my car died several times, and at one point i had to get jumped, and thats when i noticed the idle flux that made the whole car/engine shake. Replaced the alternator and everything went back to normal, except this starting issue happens every now and then, and just seems to be getting worse. any ideas what it could be?
dont remember this happening before my alternator went out, I had to drive it to the junkyard to pull one out of another '94 explorer, but getting there my car died several times, and at one point i had to get jumped, and thats when i noticed the idle flux that made the whole car/engine shake. Replaced the alternator and everything went back to normal, except this starting issue happens every now and then, and just seems to be getting worse. any ideas what it could be?