Cranks, won't start (sometimes)

[aryork]

2000 Ford Explorer 5.0L V8, 130k miles. The crank-no-start problem seems to be related to parking on a hill. Very intermittent. Right now, cranking/starting fine. I'm just now beginning to troubleshoot it and have been reading on the first dozen or so things to check (fuel pump, fuel filter, fuses, relays, crank sensor, etc.).

There are no codes showing (assuming I know how to use the code reader device).

First question: Is this the crank sensor - please see link at:

https://goo.gl/photos/tB4zPLAxzaBE352t8

That darn thing is hard to get to if that's it. I sprayed some degreaser on it followed by electrical cleaner. Seems to have cleaned some of the gunk off.

 

[koda2000]

When you have trouble starting on a hill are you nose-down or nose-up? Does this happen when the fuel gauge is above 1/4 tank? The reason I ask is that the fuel pickup is located at the rear of the fuel tank. My daughter has a 2000 Mountaineer 5.0L and a very steep up-hill driveway. She has encountered no-start if she backs up her drive with a 1/4 tank of fuel or less (she's one of those people that waits until she's running on fumes before getting gas) but if she rolls down to her level street it sill start fine.

The crank sensor is not so hard to get at from the bottom. In the picture you provided, that gear-looking thing is not the crank sensor, but its tone ring. The actual sensor is located to the left of the vibration damper (the thing in front of the tone ring) and has an electrical plug and wires attached to it.

 

[aryork]

Hi Koda, good questions on direction. I can't say I have noticed a pattern. The last time it happened it was nose-up, fairly steep, but I am pretty sure it's happened the other way around too. My sons drive the car, so it is possible it has been < 1/4 tank a lot (similar to your daughter!).

Re: the photo - I'll have to look more for the crank sensor - I know the gear itself is not the sensor - I was trying to call out to the black part that seems to be pointed at the gear. I think there is a wire coming out of it on the top, but maybe not. The radiator hoses on top are hard to see around, and there is a small radiator (oil cooler maybe??) on the bottom that is also blocking a good view of that area.

 

[koda2000]

Hi Koda, good questions on direction. I can't say I have noticed a pattern. The last time it happened it was nose-up, fairly steep, but I am pretty sure it's happened the other way around too. My sons drive the car, so it is possible it has been < 1/4 tank a lot (similar to your daughter!).

Re: the photo - I'll have to look more for the crank sensor - I know the gear itself is not the sensor - I was trying to call out to the black part that seems to be pointed at the gear. I think there is a wire coming out of it on the top, but maybe not. The radiator hoses on top are hard to see around, and there is a small radiator (oil cooler maybe??) on the bottom that is also blocking a good view of that area.

The trans cooler on a 2000 is pretty high up and nearer the grille, so that shouldn't be in your way. Maybe you also have an engine oil cooler? You might want to remove the black plastic cover from under the radiator to get a better view (just four 10mm bolts and 2 push-in retainers). You can leave the cover off while you're fooling with the crank sensor. I've driven for weeks w/out the cover while working on things w/out doing any harm. I'm not even sure of it's real purpose.

BTW, If the driver's message center says low fuel, I find that means there's only about 2 gallons of fuel retaining. That's not much when you park on a hill.

When my daughter was in college she had a brand new car with a LOW FUEL indicator light and a gas credit card. She still ran it out of gas multiple times and then complained about how the "stupid car" stopped running and then it was hard to stop and steer! Stupid car? Stupid driver... Kids.

 

[aryork]

Update to my to start problem

I believe I eliminated electrical issues (sparking fine, no fuse or relay problems). We had a cold snap and I avoided working on it for a few days. Took a look yesterday afternoon, and just for grins tried to start it first thing. No joy.

Then for the first time checked the fuel pressure via the schrader valve on the fuel rail. I don't have a gauge, so I just pressed it in and expected to get some gas coming out - which I did. I don't have a feel for if it was about the right pressure or not since this is the first time I have personally done it.

Decided to try and start it again. BINGO! Started like a charm. Drove it some. Turned off and started again fine. After sitting overnight I tried again this morning - started fine.

Is it possible there was some sort of air bubble or something in the system? I am wondering if my problem is still there, but masked somehow...

 

[bobinyelm]

I've been wondering about starts on my new-to-me '00 V8 Explorer (in fact I posted a query before seeing your post) and one of the checks I did was to operate the fuel pump (to check it was working) by removing the Fuel Pump Relay (It's #5 in the plastic box behind the battery).

To activate the fuel pump, just remove the relay (by rocking it while pulling up gently) and connect the two adjacent spade connector of the socket at the inboard side of the relay (3 and 5 if memory serves-the relay circuit diagram is printed on the sire of the relay, and the terminals are marked on the bottom). The circuit is "Hot" even with the ignition switch off, so you can do this even before even inserting the ignition key. Go back just in front of the LR tire and listen for a faint whirring of the pump motor. You could briefly depress the Schrader VERY briefly w/ the pump running and make an educated guess if you have 50psi or so pressure-remember you will be expelling flammable fuel onto the (cold) engine, so be careful.

If you let the pump run for at least 15 seconds before trying a start, you can be sure, assuming there is no leakage in the lines inside the tank, that you have good fuel pressure in the rail, so when you get in and try to start it that you have plenty of fuel pressure. For testing, you could even make up a short jumper with male spade connectors on each end and plug it into those terminals so while cranking you KNOW the pump is running and providing good pressure, in case there is something intermittent in the circuit (ignition switch, relay, etc.). Just remember to pull the jumper and replace the relay before driving off.

BTW, if you suspect an intermittent FP relay, you can swap it w/ one of the adjacent ones as they are all the same.

Just a thought, anyway.

 

[aryork]

bobinyelm: Great idea - thanks a lot! Yesterday I tried turning the ignition on and then going back near the fuel tank to listen, but could not hear it (maybe it primed and turned off or maybe my hearing is shot!). I had my son listen while I turned the key and he heard it. I will get someone else to turn it on today and listen myself to get a good feel for what that sounds like.

Probably a dumb question: does the pump run full-time while the engine is running?

Yesterday I was also looking up details on cutting through the floor to get to the fuel pump to avoid dropping the tank. I have a lift in the garage, but the truck was at the bottom of my driveway which slopes down!

 

[bobinyelm]

Hi-

Yes, the pump runs continuously as long as the ECU ells the FP relay to stay closed, and that depends on the crankshaft sensor telling the ECU the crankshaft is spinning.

Yes, it may shut-off before you can get out and hear it when turning the key on. And mine is quiet enough that w/ the engine and exhaust noise, I'm not sure if I'd hear it (I haven't tried since I ran it w/ the jumper). Some failing FPs draw more current as they are dying, so you could try using an ammeter as I did for the jumper (Set your VOM to 10a or 20a scale, and use the probes to connect to the socket connections so the current runs THROUGH your VOM).

Given that my Explorer has almost 170k, and I KNOW the FP will fail at some point, I plan to cut a hole in my floor and fashion a cover over it for when it does so replacement away from home would be easier.

 

[bobflood]

I believe I eliminated electrical issues (sparking fine, no fuse or relay problems). We had a cold snap and I avoided working on it for a few days. Took a look yesterday afternoon, and just for grins tried to start it first thing. No joy.

Then for the first time checked the fuel pressure via the schrader valve on the fuel rail. I don't have a gauge, so I just pressed it in and expected to get some gas coming out - which I did. I don't have a feel for if it was about the right pressure or not since this is the first time I have personally done it.

Decided to try and start it again. BINGO! Started like a charm. Drove it some. Turned off and started again fine. After sitting overnight I tried again this morning - started fine.

Is it possible there was some sort of air bubble or something in the system? I am wondering if my problem is still there, but masked somehow...

These are pretty classic failing fuel pump symptoms. Works intermittently; worse when it's cold out. Eventually it will fail completely - Murphy dictates that this will happen at night, in the rain/snow/cold, 100 miles from home, with no cell phone coverage, and wife/kids in the car. Go ahead and replace it now. Good luck.

 

[aryork]

bobflood - thanks! I really laugh at all the things people have to say. Was reading earlier today some guy went on a long trip and took an enormous amount of spare parts with him (like water pump, alternator, etc.) and his transmission failed! LOL!

 

[aryork]

OK, everyone get your "I-told-you-so's" ready to go...it's definitely the fuel pump and now the truck is stranded at my office instead of in my garage where my lift is! I'm hoping when it warms up this weekend I'll get the fuel pump to come alive for the drive home!

 

[bobinyelm]

OK, everyone get your "I-told-you-so's" ready to go...it's definitely the fuel pump and now the truck is stranded at my office instead of in my garage where my lift is! I'm hoping when it warms up this weekend I'll get the fuel pump to come alive for the drive home!

I'm sure you're right that it's the pump, but just as a back-up check (in case it's the fuel pump relay that controls the pump), have you removed the relay (#5 ) and jumped the connections to directly feed the pump 12v to see if it can be heard running (it is QUIET and below the front of the LR seat)? The two terminals to connect together are the two adjacent ones toward the center of the vehicle. They are terminals 3 and 5 on the relay (For Diagram Click or copy/paste: http://screencast.com/t/wTD0tR5FC1 )

You can also swap the relay next to #5 with #5 (they are the same) as a cross check before you tow the thing home.

If you jump the relay (it will get constant voltage when jumped (just put the relay in your pocket), try tapping the fuel tank hard a few times w/ voltage applied. Sometimes a physical shock will get a motor running. If the pump starts running, just start and drive it home before removing the jumper (remove it then).

Once it starts (the FP motor that is), don't trust it will re-start if you shut it off again, so just DRIVE. It's fine to drive it with the jumper in place-the computer won't even know, but remember that it will run 24/7 that way until your jumper is removed.

Bob

 

[aryork]

Started again!

The weather was in the 60s each day this weekend, so I came to the office Sunday afternoon and it started up like a charm. This is in contrast to the half-dozen other times I tried starting it with lower temps hoping to move it out of the parking deck. Drove it all the way home and into the garage with the lift!

bobinyelm: did try swapping relays and made sure I could feel the relay click when the ignition was turned on.

I plan to replace the pump this weekend, but I am very curious as to why this one seems to work in warmer weather and not in cold. Any ideas?

Is it an electrical problem with a connection expanding and making contact when it is warmer? Or some mechanical problem where something is worn out and rubbing/jamming (thinking about something rotating in the pump - I have no idea how those pumps actually pump) when it's colder but not rubbing when it warms up.

I'm planning on trying to test whether or not the pump itself is getting voltage when I drop the tank. However, the last thing I want to do is burn down my new garage by doing something stupid.

 

[koda2000]

Not starting when it's cold out is a classic symptom of a worn out fuel pump. I've replaced 4 that behaved in exactly this way. It's because the pump motor's brushes are worn down and the springs that hold the brushes against the motor's armature contract slightly when they're cold, not making a good enough electrical contact. Turn the key enough times, thump the bottom of the fuel tank with a mallet, or wait until it warms up out and the pump may start working again, but it needs to be replaced.

I find that most people here are so afraid of having to change the fuel pump that they go into denial and would rather believe the problem is anything and everything but the fuel pump. To be sure you should first eliminate the other possibilities before replacing the pump, which is a time consuming job, but not that hard to do. Testing the other possibilities shouldn't take much time to perform. I first try spraying starting fluid in the T/B for around 3 seconds. If the engine runs on the starting fluid the problem is definitely fuel related. Check fuses, swap relays and check electrical contacts, but if you've got 170,000 or more on the OE fuel pump, it's probably the problem.

 

[aryork]

Thanks! I will post next week, hopefully, about my successful, first-time FP replacement!

 

[bobinyelm]

The best way to KNOW if the fuel pump is working is to HEAR it working, and you can do that by jumping contacts 3 & 5 on Relay #5 and then listen next to the pump. It's possible the motor can run, and not make pressure, but that's 1 on a thousand-maybe the impeller is loose on the motor shaft, so if the motor runs, it's almost certainly making pressure. A split hose inside the tank (connects the pump to the fitting on top of the assembly) can reduce the pressure, but again, that's remote.

If you DO hear the pump whirring, it's likely working. If not, then 1) it's NOT getting voltage (bad/corroded connection probably at the tank connections), or 2) the motor is bad. Sometimes whacking the tank will shock the pump enough that the brushes re-make contact inside the motor and will work for a while (This works for electric window motors, too, BTW).

If you don't heat the motor, you can instead of a jumper, use an ammeter (most meters have an ammeter scale capable of reading 10a more more) to connect 3 & 5 together*. That way you are feeding the FP circuit with current that must pass through the ammeter. If you don't see 5a or so on the meter, you either have a bad connection downstream intermittently, or you have a bad pump intermittently (brushes hanging up?).

As I said, it SOUNDS like a bad pump (based on symptoms as others have said), but for the 30sec needed to electrically see the amperage draw you can learn a lot. Just like physicians use external testing before cutting a patient open, the more you can learn before dropping the tank (or cutting an access hole in your floor) the better?

*Put the probes on your meter in the Amps DC Scale, then switch the meter to the appropriate scale, then insert one probe into contact #3 , and the other into #5 . (They are the two contacts in the relay socket next to each other on the engine side of the relay box, with the blades oriented front/rear.) It doesn't matter which way you hook the meter (red/black) since if you have a digital meter you'll just have either a + or a - amp reading, and with a mechanical meter, the pointer will just go to the left, in which case, just reverse the meter leads.

 

[aryork]

Replaced the fuel pump

It took far too long, but will go quicker next time

Thanks for all the good suggestions!

https://youtu.be/_o2_sBkmq9E

 

[bobinyelm]

I'm going to do this in the next week or so-

Did you replace the whole assembly, or just the pump motor in the original assembly?

How long DID it take you to do?

Did you have access to a lift, or did you do it on jack stands on the ground?

Thanks-

If it helps at all, I once had to actually remove the entire engine just to remove the fuel tank on a VW Campmobile to replace a fuel sending unit.
Hopefully, this will be easier and less time consuming!

 

[aryork]

I did the whole assembly. I have not done trouble-shooting on the old one, but hope to do that today while it's on my mind. The instructions for doing less than the whole assy made my eyes glaze over - lots of steps and stuff to figure out. The instructions for just slapping in the whole thing were only 4 lines long. I'm not planning on getting rid of the truck, so figured putting in a new one would be reasonable.

I have a max jax lift which lifts about 4.5 ft or so. I've only used it a handfull of times, so it still makes me nervous getting under it. But, still here to talk about it. Without a lift you would need to jack it up pretty high - one of the YouTube videos that I kept seeing shows a guy with his on jack stands, and it looks high enough.

I would estimate it took me at least four hours. Hard to say because I started in the morning, then did some other stuff and came back to it. Then had to go to AutoZone twice for the fuel-line removal tool. Took me too long to siphon out the gas because I had a small tube - was hooked to a manual pump so it was easy to get started. I tried to manually start the gas siphon with a larger tube and only got gas in my mouth and never got it going (I remember doing that as a kid and it seemed easier).

The entire tank is only mounted with 3 bolts. If I did it again, I think I could do it in 2.5 hours.

 

[koda2000]

It took far too long, but will go quicker next time

Thanks for all the good suggestions!

https://youtu.be/_o2_sBkmq9E

Yeah, after doing 6 of them I 've got it down to about 90 mins and I don't rush.