NO START or STARTS AND DIES - CEL Flashes Same As Fuel Pump Relay Clicks???

[RICH JELINEK]

Check Engine Lite Flashes Same As Fuel Pump Relay Clicks???

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I've got a similar situation with our 1997 explorer, 4.0 SOHC.

Quit running on us yesterday, had to trailer it home. It will start and run for a second or two, then dies. When we got it home, about 2 hrs from when it broke down, it started right up and ran just long enough to back it off the trailer, then died again. Has spark while cranking, can hear fuel pump running for two seconds or so when turning key on. Put a fuel pressure gauge on the rail, and it does take a few cycles to get the pressure up to about 40 psi. Each cycling of the key gives it about 10 more psi - 10, 20, 30, 40. If I cycle the key like this a few times it will start up, runs for a few seconds and dies like it runs out of fuel.

Here is where it gets interesting, and I hope someone can explain this part;

When it starts up and dies, key still on, the check engine lite flashes pretty quickly and the fuel pump relay clicks along with the flashes, and before I had the fuel press. guage on the shrader valve I noticed that fuel pulses ( as I hold the schrader pin down with a small punch ) with the clicking relay/flashing lite.

Now if you try to start it again WITHOUT turning the key off, it will not start.

Turn the key off, then on again and it will start for a quick second and die, like it runs out of fuel.

Also if I pull the PCM relay, that will stop the fuel pump relay from clicking and the lite from flashing, but I guess that makes sense since that is like turning off power to the PCM, correct???

Also, when the CEL is flashing, it seems dim, like only half as bright as normal. Turn the key off and back on and the CEL is full bright.

The truck did this same deal about 2 1/2 weeks ago, and in the middle of trying to diagnose it, the problem suddenly disappeared and it has run fine since, until yesterday and now the problem is back.

Two pros have told me it is the fuel pump, but I just want to be sure before I spend the money and drop the tank to find out that was not the problem. The flashing CEL and clicking relay is what is confusing me making me think it is something else, like possibly the PCM ITSELF???

And BTW, there are NO trouble codes stored, although I am only using my Superchips Programmer from my PSD to check for diagnostic trouble codes, but I don't think that would matter?.

I also tried swapping the relays around and that didn't make any difference.

Anyone have any ideas - should I just put a fuel pump in it, or do you think it's something else???

I need to fix this thing before the problem dissappears again, it's impossible to fix it when it's not acting up, but we don't want to drive it until I find something solid so we can trust it again.

Sorry this got so long, and I didn't mean to hi-jack this thread from fordexplorerLA, but it sounds like we have similar problems.

Any help is greatly appreciated!!!


RICH JELINEK
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[marragtop]

I suggest replacing both the PCM and FP relays. I believe you said you have tried swapping them, but since they are only $5 a piece, I'd get 2 new ones. You should also take a look at the inertia switch and make sure that the connector is firmly attached. Replacing the FP would be the last thing to try.

 

[bam_bam1ca]

This isn't real easy to do unless you have a clamp-on inductive ammeter, but what are the chances of getting a current reading off of the fuel pump? If it is grounding out or drawing excessive current because the armature is stalling that might explain the CEL light dimming or flashing. It's something to check anyway..............

 

[RICH JELINEK]

Thanks for the replys guys, I will try all the simpler stuff first before I drop the tank to R&R the pump, just to be sure.

Thanks again,

 

[CDW6212R]

Start with the battery voltage, engine off, engine cold. Check the running voltage, and be sure that the fuses and relays are good. Relays don't go bad often, and basically never two at a time(swap relays, done that).

If you have enough voltage, then think about the pressure regulator and fuel pump. The pump is more common, but the regulator can go also. Good luck,

Edit: I apologize for the asssumption that I made about the truck being a 99, and needing more pressure. Jon caught my error, and I hope we continue to keep each other honest.

 

[Turdle]

Start with the battery voltage, engine off, engine cold. Check the running voltage, and be sure that the fuses and relays are good. Relays don't go bad often, and basically never two at a time(swap relays, done that).

BTW, the fuel pressure is supposed to be 62psi, you definately have a fuel problem. If you have enough voltage, then think about the pressure regulator and fuel pump. The pump is more common, but the regulator can go also. The regulator is in the tank with the pump, not on the fuel rail(99+ returnless). Good luck,

Don, excuse me if I am wrong,
I thought pre 99 (return) fuel systems were 45 psi fuel pressure

and on the 99+ returnless, the fuel pressure is 60 psi

however, it does sound like a low voltage issue--or a shorted circuit--

 

[CDW6212R]

Please excuse me, I would have sworn that RICH JELINEK had a 1999 model, I made the pressure comment due to that. You don't necessarily have a pump problem then. It is possible for the pressure regulator to bleed off too much pressure, the injectors can contribute to that. Since you have a regulator on your fuel rail, I would check the CEL's, voltage of the battery, alternator, and pump relay. If those are good, I would guess the regulator, it isn't that hard or expensive.

Yes Jon, the 98 and older FI's run low 40's of pressure, 45psi would be high actually. I just learned about the higher 62psi systems lately. I wonder if that has helped with efficiency. I also wonder if my 99 is a little off in pressure, I have just a first and second crank starting problem. My SOHC always starts by the third crank, but turning the key on and off has no affect on mine.

 

[RICH JELINEK]

Our Explorer is a 1997 model, and I'm pretty sure I'm looking at the reg. on the fuel rail.


ANYWAY, I tried the relays, made no difference. Double checked all connections, fuses, and the inertia switch by the pass. feet - it is not tripped, but I did notice that whether it is plugged in or not the problem is the same - is this correct??? ( I just thought of this now... )

So moving on I dropped the tank and put in a new fuel pump/sender/screen as a complete unit as well as replaced the fuel filter - SAME PROBLEM!!!!

The only difference I see now is that as the fuel pump primes for the 2 secs. at key on I can hear some gurgling sounds as if the pump is cavitating or has some air in it???

But it still either won't start or will fire up and die after 2 - 3 seconds and when it dies the CEL flashes and the fuel pump relay clicks on and off right along with the CEL flashes.

ALSO it still takes 2 - 3 cycles of turning the key on and off to get the fuel pressure to come up to about 40 psi at the rail schrader valve.

The biggest thing throwing me off is the CEL flashing and the FP relay clicking after the engine dies, and when you turn the key off and then back on all that stops - can anyone explain that part of this deal????

Could it be the ECM/PCM gone bad, or does that have nothing to do with this problem???

Someone told me it could be the ignition module, ( and I'm honestly not even sure where that is on this thing ) but even when it won't start, it has good spark at the spark plug.

I'm trying to at least figure out if it's a mechanical part, a computer part/sensor, or an electrical part/problem/gremlin???

Anybody got any other ideas???

Thanks again for all the replys!

 

[budwich]

Your statement about the "inertia switch" isn't "accurate"... I suspect. With the unit disconnected, your fuel pump should NEVER turn on. With it plugged in and "functioning", your pump should turn on for a "few seconds" if a "no start" condition exists for a "period". Just saying your "problem is the same" isn't really accurate. You need to confirm this part of your testing for accuracy of your results as you may be chasing different problems depending on the result.

 

[CDW6212R]

That CEL flashing makes me think that the PCM can sense fuel pressure or something else related to the fuel system.

Again allow me to apologize for misunderstanding your model year. You do have a pressure problem though if you don't get full pressure with one turn of the key.

Did you confirm that the voltages are okay? If so I would have gone for the fuel pressure regulator, it's much easier to buy and replace.

Also one last thought, related to the PATS system which began during the 97 model year. Do you have a theft light in the instrument cluster, and does it stay lit while cranking. It should not flash when you turn the key on. For the PATS systems the first thing checked is the key code, if it doesn't match then the fuel circuit is interrupted, thus the fuel pump will only turn on for an instant, not a full second or so. Regards,

 

[Turdle]

Our Explorer is a 1997 model, and I'm pretty sure I'm looking at the reg. on the fuel rail.


ANYWAY, I tried the relays, made no difference. Double checked all connections, fuses, and the inertia switch by the pass. feet - it is not tripped, but I did notice that whether it is plugged in or not the problem is the same - is this correct??? ( I just thought of this now... )

So moving on I dropped the tank and put in a new fuel pump/sender/screen as a complete unit as well as replaced the fuel filter - SAME PROBLEM!!!!

The only difference I see now is that as the fuel pump primes for the 2 secs. at key on I can hear some gurgling sounds as if the pump is cavitating or has some air in it???

But it still either won't start or will fire up and die after 2 - 3 seconds and when it dies the CEL flashes and the fuel pump relay clicks on and off right along with the CEL flashes.

ALSO it still takes 2 - 3 cycles of turning the key on and off to get the fuel pressure to come up to about 40 psi at the rail schrader valve.

The biggest thing throwing me off is the CEL flashing and the FP relay clicking after the engine dies, and when you turn the key off and then back on all that stops - can anyone explain that part of this deal????

Could it be the ECM/PCM gone bad, or does that have nothing to do with this problem???

Someone told me it could be the ignition module, ( and I'm honestly not even sure where that is on this thing ) but even when it won't start, it has good spark at the spark plug.

I'm trying to at least figure out if it's a mechanical part, a computer part/sensor, or an electrical part/problem/gremlin???

Anybody got any other ideas???

Thanks again for all the replys!

Somewhere, there is a short. Sorry--I'm betting on the PCM being bad--

Try Ped5stang for a used one maybe???

 

[RICH JELINEK]

Your statement about the "inertia switch" isn't "accurate"... I suspect. With the unit disconnected, your fuel pump should NEVER turn on. With it plugged in and "functioning", your pump should turn on for a "few seconds" if a "no start" condition exists for a "period". Just saying your "problem is the same" isn't really accurate. You need to confirm this part of your testing for accuracy of your results as you may be chasing different problems depending on the result.

I am not sure how the inertia/crash switch should work, but all I do know is that the truck acts the same wether the switch is plugged ( three wires I think ) in or not - is this correct or could the switch be the problem???

 

[CDW6212R]

That switch completely interrupts the power going to the fuel pump. The truck cannot start with that unplugged.

Last time, have you confirmed proper voltages? Do you have a theft light illuminated in the dash? Does it flash with the key turned on?

You should not have changed the fuel pump until you elliminated the other basic possibilities. Plus the regulator is far easier to buy and install. Good luck,

 

[RICH JELINEK]

That CEL flashing makes me think that the PCM can sense fuel pressure or something else related to the fuel system.

Again allow me to apologize for misunderstanding your model year. You do have a pressure problem though if you don't get full pressure with one turn of the key.

Did you confirm that the voltages are okay? If so I would have gone for the fuel pressure regulator, it's much easier to buy and replace.

Also one last thought, related to the PATS system which began during the 97 model year. Do you have a theft light in the instrument cluster, and does it stay lit while cranking. It should not flash when you turn the key on. For the PATS systems the first thing checked is the key code, if it doesn't match then the fuel circuit is interrupted, thus the fuel pump will only turn on for an instant, not a full second or so. Regards,

This PATS thing opens up a whole nother can of worms..................I'm not even positive if ours has it, since most sources say it was intoduced in 1998, with SOME models getting it in 1997, but we do have a THEFT lite on the dash. The only time the THEFT lite is on is when you close and lock the doors. It does not come on with KEY ON and is does not lite at all while cranking.

As far as the keys go, I dug up the three spare keys we have and they all work the same, problem still there with any key.

NOW I forgot to mention earlier that we did have a cheapo remote start on it for about 1 1/2 yrs. When this started giving us trouble a few weeks ago, the engine would stall/die but would start right back up again. My wife swears that it seemed like it would run for exactly 10 mins and die/stall again, but would start right back up. Since the remote start was programmed to run for 10 mins and shut of if you didn't drive away, we thought maybe the remote start was going haywire so I removed the unit. That was about two weeks ago and it ran fine that whole time until a few days ago when we had to trailer it home and now it has the problems all mentioned above.

I left most of the wiring tied in for the remote start, I just removed/unplugged the unit itself to take it out of the picture, and I have checked all the wiring involving the remote start and I'm pretty positve that no wiring is shorted etc., but maybe I'll check again.

The other part I don't get is how this truck had the problem, then for about two weeks it was gone/fine, and now it's back again - sounds like it's haunted!

Thanks again for all the help, and please keep the info coming

 

[RICH JELINEK]

That switch completely interrupts the power going to the fuel pump. The truck cannot start with that unplugged.

Last time, have you confirmed proper voltages? Do you have a theft light illuminated in the dash? Does it flash with the key turned on?

You should not have changed the fuel pump until you elliminated the other basic possibilities. Plus the regulator is far easier to buy and install. Good luck,

As far as proper voltages I assume you mean battery voltage???

It has 13.0 - 13.2 volts at the battery, can't check charging voltage since it won't run, but I'm positive that's not an issue.

Theft lite only is on with the doors closed and locked, does not flash with key on.

I really didn't think the fuel pump was the problem BUT I foolishly trusted the 10 or so different people that told me how common it is for fuel pumps to go bad in these things and that has GOT to be it. I should have trusted myself!

Back to the switch in the pass. feet area, it it possible to jumper that out or test the switch with an ohmeter/cont. lite to see if that switch is bad???
Or am I barking up the wrong tree with that??

 

[CDW6212R]

Okay, then you don't have PATS, that was my problem on my 98 truck. I changed the fuel pump before discovering that.

Still, if you have voltage problems from either the battery or the alternator, you cannot decide whether the pump or regulator is at fault.

If you do have good voltage, then the pressure should come up to 35-40psi on first turning on the key.

How does the pump sound when you first turn the key on? Turn everything else off so that you can hear it well. The pump should run clearly for about one second. When my PATS unit was killing my signal, the pump would run for maybe 1/4 of a second.

If the pump sounds proper with key on, and the voltage is correct, and the pressure does not reach proper levels on first try, then leakage is the problem. Fuel injectors are least likely, look at the regulator, call for a price locally. Good luck,

 

[CDW6212R]

Engine off battery voltage should not really ever be 13 volts, 12 to 12.5 would be good. Running voltage should be over 12.5, closer to 13.5-14.5. Improper voltage can kill a fuel pump and a lot of things.

The inertia switch can be bypassed, I did that just before changing my pump. But actually the only thing that usually goes wrong with them is damage from something contacting/hitting them, like one's feet etc. If it all looks good, and the wires test fine, there should be no need to bypass it.

 

[RICH JELINEK]

Still playing around with this thing...........here's something I just came across, if this matters.

When it trys to start or does start and run for a few seconds then dies, with the key still on, I just noticed that along with the check engine lite flashing, the fuel pump relay clicking the IDLE AIR CONTROL motor/solenoid clicks along with them. I took it off and it does not look eccessively dirty, but could it be locked up or stuck and be causing all this ???

ANY ideas???

Thanks,

 

[CDW6212R]

Good luck,

 

[RICH JELINEK]

Good luck,

I'll take that as though this is some freakish problem and you're out of ideas???

Thanks,