No cold weather start and no fuel pump operation

[BillF]

Hi Everyone,

I have a cold weather no start issue with my 1999 4.0 SOHC Explorer. This has been an issue for a few years now during colder periods of weather. I searched through all of the forums regarding similar issues, but never found an issue or solution that exactly matches mine.

The main problem is with fuel delivery. During colder days 20 - 30 degrees F, I do not hear the fuel pump prime and no fuel is at the manifold rail check valve. It will try to start with ether sprayed in the throttle body, but is dies quickly. This tells me the spark is OK. It is producing no OCD codes and of course when the dealer looked at the truck, it worked fine. It cranks strong, has a new fuel filter, plugs and wires, fresh gas and overall just does not activate the fuel pump. I have followed the no start procedure for the fuel pump issue posted on this forum.

I jumpered the fuel pump relay (#9) and the pump did not come on. I put in a new fuel pump relay and same problem. I detached the connection on the wiring (sending unit C311?) near the gas tank and it looks good. This connecter only had 2 pins, did I find the right one? The crankshaft positioning sensor looks OK during a visual inspection.

The check engine light is illuminated when the key is on and goes off while attempting to start the truck. Does this rule out a PCM issue? The PCM fuse and relay are OK. A full open throttle during the attempted starting does not do anything, either. The inertia switch is pushed down and never was tripped.

The only noise I hear before the starter kicks in is a slight hum from the passenger side kick board where the inertia switch and PCM are located.

It only appears to have this issue in colder weather. It was fine all spring, summer and fall. About a week ago when it was about 40 degrees F, it would not start. I put a hair blow dryer near the thermostat for about 15 minutes and then it started. 4 days later on the very next attempt to start, no fuel pump prime/hum sound, but it was only 25 degrees outside and has not started since and the days are still only in the 20's and low 30's. I live at 5900 foot elevation.

I thought it may be the ETC sensor or IAC, but it appears from other members posts neither of them would create a no start condition. I tried to heat up the area around the thermostat on a 25 degree day, but it did not work this time. In the past, it would start the next day or if I let it sit outside in the sun. So I next ried to use a little 1500W heater near the passenger kick panel to heat up the PCM and inertia switch area to approximately 60 degrees with no success. I have read a lot about intake manifold leaks, but would this cause a no start condition? The truck runs just fine when it finally starts.

I am almost certain that it is not the fuel pump because of identical cold start issues in the coldest months from 2014 until now. How could a fuel pump sporadically work for 2 years? Does anyone have any ideas, because a trip to a mechanic will likely replace parts that are not really failing and cause even more frustration. What could be causing the fuel pump not to activate in cold weather? Thanks!

 

[koda2000]

Replace your fuel pump. The symptoms you report are typical of an old worn out fuel pump. The motor brushes wear out and the brush springs get weak. When it gets cold out they don't make contact with the armature and the pump wont run. I've had 4 fail in the same manner. They all worked during the summer and starting working intermittently when it got cold out.

BTW, It's not at all unusual for an electric motor to work intermittently. That's why people tap on a starter motor, or blower motor, with a hammer to get them spinning in a pinch. Sometimes smacking the bottom of the fuel tank with a rubber mallet will get a fuel pump to run.

 

[BillF]

Thanks Koda for the reply. It is also worth to note that I can not get the proper voltage is the power distribution box for relay 9 (fuel pump). When I had the jumper between 3 and 5 (30 and 87 on the relay), trying to start the fuel pump, I put a volt meter on the jumper connections and only had 1.6V with the ignition switch on. Is this normal?

I will look into replacing the pump. Will I need anything else besides the actual pump? Electrical connectors, tubes, senders. float, flange, inlet filter, ect...?

Thanks.

 

[Robman]

The plug for the fuel pump is tucked into the driver's side frame rail and clipped there. Crawl under, disconnect the plug and test the voltage there. That's where I would check it anyway.

When yer fuel pump goes, usually you end up checking a whole bunch of stuff and make it harder than it needs to be.

Can always grab a pump from the scrap yard for confirming things. Not sure if you'd want to, but I cut an access hole from under the back seat to the fuel pump and make up a cover for it when I'm done. Makes fuel pump swaps a cinch.

 

[koda2000]

Thanks Koda for the reply. It is also worth to note that I can not get the proper voltage is the power distribution box for relay 9 (fuel pump). When I had the jumper between 3 and 5 (30 and 87 on the relay), trying to start the fuel pump, I put a volt meter on the jumper connections and only had 1.6V with the ignition switch on. Is this normal?

I will look into replacing the pump. Will I need anything else besides the actual pump? Electrical connectors, tubes, senders. float, flange, inlet filter, ect...?

Thanks.

This is what I use in my 2000's/2001's (I don't know if it also fits the '99. I assume it would if the '99 is a return-less system). It comes with a everything pictured. You wont need all of it. You will need to purchase a new strainer sock filter and a new in-line fuel filter.

http://www.ebay.com/itm/Electric-Fu...ash=item43cd775259:g:dtEAAOSwDNdVrpDK&vxp=mtr

Stay away from Airtex fuel pumps. They're junk!

Edit: I searched eBay for a '99 Explorer and it came up with this number... Seems to me I called Bosch tech support about these pumps once before and they said either would work.
http://www.ebay.com/itm/Bosch-69134...ash=item3f4dac6e8d:g:r60AAOSwrklVarev&vxp=mtr

 

[BillF]

Fuel Pump ordered

Thanks for the help guys! I ordered a fuel pump that is due to be delivered in a few days. I will do the tank drop procedure and install the new pump within the sending unit. I'll post on the results then. I hope everyone is having a great New Year!

 

[BillF]

Fuel line issue

I have dropped the tank to get ready for the new fuel pump installation. My problem now, and it seems most have this problem, is the fuel line at the top of the gas tank.

I tried to use one of the plastic round sleeve type tools (light green in color) that was 3/8" without success. I sprayed PB blaster and used compressed air, but still no luck after 3 hours of trying. There are many posts about this, but the suggestions did not produce any luck for me.

Should I try a different tool? If the line will not come off, is it possible to cut the fuel line along the frame rail, remove the sending unit, replace the pump and splice the frame rail fuel line with normal black rubber fuel line and standard hose clamps?

Any and all suggestions are welcome!

Thanks Guys!

 

[Robman]

Get the metal tool..

I spray a bit of wd40 in there and tap the metal tool inward, with your hand work the line in and out. It can be kinda tough but you'll get it and I wouldn't be cutting any lines.

 

[koda2000]

I have dropped the tank to get ready for the new fuel pump installation. My problem now, and it seems most have this problem, is the fuel line at the top of the gas tank.

I tried to use one of the plastic round sleeve type tools (light green in color) that was 3/8" without success. I sprayed PB blaster and used compressed air, but still no luck after 3 hours of trying. There are many posts about this, but the suggestions did not produce any luck for me.

Should I try a different tool? If the line will not come off, is it possible to cut the fuel line along the frame rail, remove the sending unit, replace the pump and splice the frame rail fuel line with normal black rubber fuel line and standard hose clamps?

Any and all suggestions are welcome!

Thanks Guys!

I don't remove the fuel line anymore, because it's a major PITA and unnecessary if you're just replacing the pump. I drop the tank enough to disconnect the hoses electrical plugs and the evap line. Then I remove the 6 bolts that hold the assembly in the tank, drop the tank to the ground and finagle the assembly out of the tank, being careful not to bend the float arm. Once the assembly is out I stick it on the top of the leaf spring to work on it.

Putting the assembly back in the tank takes some patience to line everything else up. I've discovered that using tie-wraps to hold the front of the tank up loosely and using a low floor jack at the rear makes the job pretty easy.

I've changed 4 Explorer/Mountaineer fuel pumps in 2015 and have a 5th on my to-do list, so I'm pretty damn good at it.

 

[chefduane]

Koda, what's your take on cutting the access door in the floorboard below the left passenger seat above the tank? I know I need a new FP in my '98 but really don't want to drop the tank. Cutting a door then re-sealing it sounds a lot easier, eh? Know of anyone that's done it?

 

[koda2000]

Koda, what's your take on cutting the access door in the floorboard below the left passenger seat above the tank? I know I need a new FP in my '98 but really don't want to drop the tank. Cutting a door then re-sealing it sounds a lot easier, eh? Know of anyone that's done it?

Personally I wouldn't do it, but I don't have rust to deal with, nor sub-zero temps, plus I have spare vehicles I can drive. I guess if done neatly and if you can make and seal a cover over the hole it's an effective option, but it just rubs me the wrong way (especially seeing some of the hack-jobs people have done).

Ford should have provided an access panel for this purpose, but as they didn't I prefer to do it the right way and just drop the tank. If it's your daily driver and you can't have it down for more than a day or two, do what you gotta do I guess. There's a STICKY which shows you where to make the cuts, but I don't know if it's for a Sport or 4-door. Many here have done it.

 

[BillF]

Finally Completed

The pump arrived this morning and I used Koda2000's method of removing the assembly without disconnecting the fuel line. See his post above for additional information. By far the hardest and most frustrating aspect of this entire procedure was this fuel line. I did not have any issues with the fuel filter. If I had the cut-out beneath the rear seat, it would not have helped. The tank drop worked well for me.

I test drove the truck and checked for leaks, etc. I was not too happy to take the test drive in fresh snow as everything appeared to be a leak from melting snow on the undercarriage. I'll take a closer look when it drys out, but I am sure everything is tight and snug.

I would like to thank Koda2000 and Robman for their expert advice and guidance.

The post titled " Fuel Pump Replacement - 2000 Explorer Sport" by 2000StreetRod was spot on and was extremely helpful. My 99 Eddie Bauer 4door 4WD has the exact tank and fuel pump assembly as his 2000 Sport configuration.

My only suggestion to anyone doing this procedure in the future is to have a variety of fuel removal tools (Koda2000's method is always going to work, too) and to check the air in your spare tire when you have it down and also lubricate your spare tire lowering mechanism.

Thanks to all again!!!

 

[koda2000]

The pump arrived this morning and I used Koda2000's method of removing the assembly without disconnecting the fuel line. See his post above for additional information. By far the hardest and most frustrating aspect of this entire procedure was this fuel line. I did not have any issues with the fuel filter. If I had the cut-out beneath the rear seat, it would not have helped. The tank drop worked well for me.

I test drove the truck and checked for leaks, etc. I was not too happy to take the test drive in fresh snow as everything appeared to be a leak from melting snow on the undercarriage. I'll take a closer look when it drys out, but I am sure everything is tight and snug.

I would like to thank Koda2000 and Robman for their expert advice and guidance.

The post titled " Fuel Pump Replacement - 2000 Explorer Sport" by 2000StreetRod was spot on and was extremely helpful. My 99 Eddie Bauer 4door 4WD has the exact tank and fuel pump assembly as his 2000 Sport configuration.

My only suggestion to anyone doing this procedure in the future is to have a variety of fuel removal tools (Koda2000's method is always going to work, too) and to check the air in your spare tire when you have it down and also lubricate your spare tire lowering mechanism.

Thanks to all again!!!

Glad everything worked out well for you. I doubt you'll experience any leaks. I never have.

FYI, If it is necessary to disconnect the fuel line from the assembly, I find a metal 3/8" disconnect tool will work, but it's still not the easiest thing to do, as you need to push the fuel pump assembly into the line (in much the same way you need to do this to remove the fuel filter) while pushing the tool into the fitting. The first time I did this I tried for 2 hours with a plastic tool and got nowhere. Then I when and bought a set of metal tools and found the 3/8's size worked, but it still probably took me 10 minutes.

 

[Map99]

I have a 99 Explorer sport. Will not start if it's below 50 outside. Just replaced the fuel pump. Drove all day on a 60 degree day. 43 today and same issue. Will not start Could it be the relay? Any suggestions?

 

[koda2000]

Can you hear the fuel pump prime when you turn the key to ON? It should run for about 2 seconds every time you turn the key to the ON position.

Is your check engine light on? Does it work during the bulb check? What V6 engine do you have (OHV or SOHC)? When your engine does start, does it run rough until it warms up?

If the fuel pump is not priming, it could be a bad relay, a loose relay contact, or corrosion at the relay contacts. Pull the fuel pump relay, examine the contacts, swap the relay for a similar non-critical relay in the power distribution box (like the A/C relay). You can also tweak the metal contacts on the relay ever so slightly using a pair of pliers to make better contact. Another thing to check is the inertia switch contacts. The inertia switch is located above the passenger side interior kick panel, below the dash. Sometimes it's connections can become burnt of corroded and not make a good contact every time.

If the fuel pump is priming and it will still will not start. it could be you're not getting spark. The crank position sensor sends a signal to the ECU so that it knows when to generate spark. My '97 would do this about twice a year. The crank position sensor is located on the passenger side front of the engine at about the 7:00 position off the harmonic balancer. Mine apparently had a bad connection or wire. On the rare occasion the engine would crank and not start, I'd get no spark. Wiggling the connector and its wires would always get it going again. I verified I had no spark before checking the crank sensor. The sensor itself is a very simple Hall effect device and rarely gives problems, but on an older vehicle electrical connections are always suspect. If you have battery jumper cables and old spark plug I can tell you how to test for spark easily and safely. Trust me, you don't want to get hit with 60,000 volts if you help it.

As your engine will run, your problem has to be fuel or spark related. The only other things that I can think of that could cause a crank-no-start when it's cold out is a bad coolant temp sensor, or on a SOHC V6 (if that's the engine you have) maybe leaking intake manifold O-rings.