94 2.3 fuel system issue

[racsan]

every so often my ranger would not want to start, i sometimes could get it to go by using either or putting a charger on battery for more boost, makes no sence cause its a new battery but thats what was happening, mostly when it was really cold out. well now it wont start at all, will fire off of the either but one the either is used up thats it. i do hear noise from the fuel pump area when key is first turned on, like its building pressure then shutting off, but theres no fuel at schrader valve on fuel rail or underneath when i took line off of back side of fuel filter. i bypassed the shut-off inertia switch and that did nothing, i do think pump must be dead, not sure why it makes noise like its pressurizing then clicking off but no fuel at fuel filter. is there any in-line pump i could buy to put underneath? bad time of year to pull the bed, must have 300# of stuff back there right now, cant drop the tank, its a 20 gallon from a '97 and while its securly mounted, its not really possible to drop it- and its full of fuel. if i have no choice but to put a new pump in tank, whats the best one? i damn sure dont want to do this again..... miss the days of a engine mounted pump that took 2 clamps, 2 bolts, 30 bucks and about 30 min to swap out...

 

[BlackBII]

but theres no fuel at schrader valve on fuel rail or underneath when i took line off of back side of fuel filter.

This makes it sound like the pump isn't working at all. It's hard to be certain until you drop the tank or remove the bed and pull the pump to test it. The filter on the pump could be clogged as well, if you hear the pump coming on but have no fuel in the lines.

If you do end up replacing the pump, I recommend the Bosch unit. I tried an Airtex Wells and it left me stranded after 3k miles.

 

[racsan]

well the stock pump was indeed dead, ive tried something and so far its working, a msd 2555 inline fuel pump, 45 psi. mounted it right along side the fuel lines near the fuel filter. in fact now there are 2 fuel filters, one on each side of the pump, the factory line attaches to each filter and the other end of the filter has 5/16 line slid over the filter , the inlet to the msd pump is 3/8 so used fittings to make a 3/8-5/16 adaptor. power is through the underhood fuse/relay box, pulled the stock fuel pump relay and figured out which spot was hot with key on but off with key out, put a spade lead in there with a 25 amp fuse on it. pump is a little noisy (heck, its meant for when you swap in a efi engine into a non-efi chassis) but it works. gas guage still works, it must get its power source seperatly. was about 130 for the pump, filters 9 a piece, im guessing another 20 or so for the hoses, clamps and wiring. yes a stock pump might have been a little cheaper but it sure was easier and quicker to do it this way.

 

[Mark_88]

I'm not sure why Ford went to the in tank pumps. My first 88 with the 2.9 had two pumps...the in tank low pressure pump and the high pressure pump that was mounted on the frame rail buy the footwell.
On the 88 carbed 2.0 I only had the manual pump mounted on the block. When that failed I just put one inline up near the carb and it worked great for three years. When it died I just replaced it with the same low pressure pump and never had a problem with fuel delivery with that config.

I'm not familiar enough with the reasoning behind it other than safety/inertia switch shut offs but that can be wired into a pump out of the stock config. If you have the original inertia switch wiring that might be worth hooking up if you didn't do it already.

 

[kishy]

Well...given that virtually everyone "went to" in-tank fuel pumps, and in that time period externally mounted pumps were the "weird" choice, I don't think there's any sense in questioning Ford's motives specifically. There was almost certainly an engineering reason and I'm inclined to believe it's something loosely based on:
1) 2 pumps costs more to build (and introduces an extra failure point), so the lift+pressure system was silly and wasteful, and
2) the pump will have to work less and risk running dry less if the pump is typically submerged in the fuel, since the check valve to avoid drainback is inside the pump

If you installed an inline pump, you have to drop the tank and remove the one in the tank, and build a pickup tube to reach the original bottom of the in-tank pump. If you continue to run the inline pump forcing it to pull fuel through the in-tank pump, your inline pump has to work harder, will fail sooner, and you could introduce a fuel delivery issue if the inline pump can't successfully suck enough fuel through the in-tank pump in conditions where fuel demand is high. I don't know if the 2.3 will ever be thirsty enough for that to happen, but still, your external pump will shit the bed prematurely if it has to fight against the non-operational one in the tank.

On the flip-side, the pump inside the tank contains a check valve (usually, anyway), so eliminating it will allow fuel drainback and could lead to harder starts (which to my understanding is the typical symptom when the lift pump dies in a 2-pump truck but the pressure pump still works - e.g. what OP has now done to his truck). The only way to win here is to replace it properly.

Fuel pressure and flow are related but not the same thing. The inline pump will give you sufficient pressure but it may not give you sufficient flow because of that restriction in the other pump.

 

[adsm08]

Well...given that virtually everyone "went to" in-tank fuel pumps, and in that time period externally mounted pumps were the "weird" choice, I don't think there's any sense in questioning Ford's motives specifically. There was almost certainly an engineering reason and I'm inclined to believe it's something loosely based on:
1) 2 pumps costs more to build (and introduces an extra failure point), so the lift+pressure system was silly and wasteful, and
2) the pump will have to work less and risk running dry less if the pump is typically submerged in the fuel, since the check valve to avoid drainback is inside the pump

You are pretty much correct here. You left out one important one.

Like any electrical component a fuel pump creates heat, which is bad for it. Having it submerged in fuel helps cool it.

 

[Mark_88]

Well...given that virtually everyone "went to" in-tank fuel pumps, and in that time period externally mounted pumps were the "weird" choice, I don't think there's any sense in questioning Ford's motives specifically. There was almost certainly an engineering reason and I'm inclined to believe it's something loosely based on:
1) 2 pumps costs more to build (and introduces an extra failure point), so the lift+pressure system was silly and wasteful, and
2) the pump will have to work less and risk running dry less if the pump is typically submerged in the fuel, since the check valve to avoid drainback is inside the pump

If you installed an inline pump, you have to drop the tank and remove the one in the tank, and build a pickup tube to reach the original bottom of the in-tank pump. If you continue to run the inline pump forcing it to pull fuel through the in-tank pump, your inline pump has to work harder, will fail sooner, and you could introduce a fuel delivery issue if the inline pump can't successfully suck enough fuel through the in-tank pump in conditions where fuel demand is high. I don't know if the 2.3 will ever be thirsty enough for that to happen, but still, your external pump will shit the bed prematurely if it has to fight against the non-operational one in the tank.

On the flip-side, the pump inside the tank contains a check valve (usually, anyway), so eliminating it will allow fuel drainback and could lead to harder starts (which to my understanding is the typical symptom when the lift pump dies in a 2-pump truck but the pressure pump still works - e.g. what OP has now done to his truck). The only way to win here is to replace it properly.

Fuel pressure and flow are related but not the same thing. The inline pump will give you sufficient pressure but it may not give you sufficient flow because of that restriction in the other pump.

That all makes perfect sense and may be a safer way to do things. On the earlier models of the 2.0 that was carbed there was only the pickup tube with an external pump on the block. It was very low pressure so there wasn't a risk of blowing fuel under pressure around to create a serious fire risk if the pressure pump became disconnected on the business end.

And I'd imagine that worrying about someone having to raise the box or drop the tank was the least of their concerns...

I found the pump under the hood made way more sense than burying it in the tank and fortunately I never had a problem that involved needing a way to shut off the pump...other than killing the ignition or having the battery disconnected.

The OP might never need to worry about that event either...but should the need arise it's probably better to take the initiative and hook up a way to disrupt the fuel flow that doesn't involve action by a driver that may be temporarily out of commission.

I'm sure there are legal ramifications to any modification that might endanger lives...and those are serious challenges that require adherence to safety features...

 

[kishy]

You are pretty much correct here. You left out one important one.

Like any electrical component a fuel pump creates heat, which is bad for it. Having it submerged in fuel helps cool it.

Yes...that. I'm aware of it, but in the context of pumps designed to run inline on the line outside of the tank, I think they usually have a casing/body that acts like a heatsink...I may be mistaken though. There could be installation requirements such as "must be mounted to clean metal surface" or something like that for heat dissipation.

Either way, yes, submerging a heat source in a body of liquid has a huge effect on its operating temperature.

Mark: agreed that the simplicity of the engine-mounted low pressure pump has a convenience benefit when failure happens. On the other hand, I believe failure happened more often with those due to the moving diaphragm in them.

I didn't even touch on power delivery because it's such a can of worms. What he could do is take the power feed that goes to the in-tank pump and just use that. Inertia switch and all, already in the circuit. But, if the circuit was never verified to be OK and just the pump assumed to be dead, then maybe the real problem will surface. Relays do go bad, especially ones that see constant duty after 20 years or so.

I thought this topic seemed familiar. http://www.fordrangerforum.com/4-cylinder-tech/143411-94-2-3-fuel.html#post2741879

OP: if you want to continue with the external pump, that's not a problem in itself. But you need to address the way it's wired and get the in-tank pump out of the picture, or this band-aid is potentially just making more headaches for you.

 

[Mark_88]

Yes...that. I'm aware of it, but in the context of pumps designed to run inline on the line outside of the tank, I think they usually have a casing/body that acts like a heatsink...I may be mistaken though. There could be installation requirements such as "must be mounted to clean metal surface" or something like that for heat dissipation.

Either way, yes, submerging a heat source in a body of liquid has a huge effect on its operating temperature.

Mark: agreed that the simplicity of the engine-mounted low pressure pump has a convenience benefit when failure happens. On the other hand, I believe failure happened more often with those due to the moving diaphragm in them.

I didn't even touch on power delivery because it's such a can of worms. What he could do is take the power feed that goes to the in-tank pump and just use that. Inertia switch and all, already in the circuit. But, if the circuit was never verified to be OK and just the pump assumed to be dead, then maybe the real problem will surface. Relays do go bad, especially ones that see constant duty after 20 years or so.

I thought this topic seemed familiar. http://www.fordrangerforum.com/4-cylinder-tech/143411-94-2-3-fuel.html#post2741879

OP: if you want to continue with the external pump, that's not a problem in itself. But you need to address the way it's wired and get the in-tank pump out of the picture, or this band-aid is potentially just making more headaches for you.

I think his initial consideration was the stuff in the bed that is considerably more than I ever carried and the fuel levels that are a pain to pump out into other containers for the duration (regardless of how short) and all the added effort to do it the way it should be done.

I once drained a fuel tank using the external pump and it made me consider keeping one around for just such uses. I still have that pump somewhere...it did the trick and I was able to get an otherwise time consuming task done much quicker.

I'm sure the OP will take that advise as quickly as he can...in times of "do what works to get by" I've done similar (or worse) things...like disabling my rear driver side brake cylinder when the line broke and I couldn't make time or find the resources to fix it properly...

I eventually fixed it and hardly noticed the reduced braking power...not like my 2.3 carbed engine made enough power to get going faster than a speeding turtle...