Just a quick question if I can please. Is it true that I can test the tank pump on my bench with a little 9 volt battery? Now that the tank is under my deck, I do not have a 12 volt source readily available unless I go pull a car or tractor battery. Battery charger maybe? I just don't want to fry the pump if indeed it is good. Do I need to have the pump picking up fuel when I test it on the bench also? Just to keep it from burning up or do I just want to hear if it turns on or not?

Thanks

Sid

 

You just want to know if it turns or not. Stay far away from fuel as you can.
I do not know if a small 9Volt battery will run it or not. I use a bench power supply.
Battery charger may be OK.

 

Well back at it again. I have traced every wire and ground applicable to this dual tank system. I have found every splice and they are good. All relays are working. The hi pressure pump works. The rear tank pump works. Last check was 12 volts as far up to the front tank pump connector as I could get without dropping the tank. Dropped that tank today and it has 12v to the connector as well. The selector switch as you know is new and is wired correctly. The front tank pump does not spin. Even though it was newly replaced a few months ago, I am going to have it replaced again. Can you tell me please what is the gallon size of my front and rear tank? It is a 1990 E250 cargo van. 138" wheel base with the 302 motor in it. I put an Airtek pump in the tank a few months ago. That is what NAPA is replacing with it free of charge. Without a receipt mind you. Quite nice of them so I cannot be picky. Is there anything I could have done wrong about putting the pump in the first time? Oh yeah, new selector valve also.

Thanks

Sid

 

The only specifications I have that may apply are for 1989 E-250 Wagons.
Aft/Axle = 22gal & Midship = 16gal.
And that is for steel tanks.

 

Thank you sir.

 

Afternoon all,

Well if after finally replacing the front fuel pump again and putting both tanks back up into the van, I finally put 7 gallons of gas in the front tank and the rear is still empty. Both tank pumps work and have been verified. the hi-pressure pump turns on when the key is turned. All 3 pumps will turn off after a second or two after turning the key switch on. Of course depending on which tank is selected. The front tank is reading a little under a half so the sender and its wiring is good. Go to fire the van up and all it did was turn over and over. No fire. I figured maybe I needed to let the pumps push some fuel up to the fuel rail since everything was emptied. Tried again repeatedly. Still no fire. I got under the van and pulled a fuel line coming out of the selector valve that goes into the hi pressure pump. Turned the key and plenty of fuel at a good rate came out. Front pump and selector valve working. Pulled the line off the exit side of the hi-pressure pump. Turned the key and barely anything came out. I pulled the line off the entry to the hi-pressure pump to make sure the line coming from the selector valve wasn't blocked going to the hi-pressure pump. Turned the key and plenty of gas came out at a good rate. Plugged all the lines up and tried to start again. Still nothing. Pulled the line of the exit from the hi-pressure again and this time fuel came out but it was about as strong as the fuel coming out of the selector valve. I'm thinking if it is a hi pressure pump it should be significantly higher pressure than the tank pumps. I plugged the line up anyway. Just to check I pulled the line off the exit side of the filter to see. The same rate and amount of fuel came out of the filter as was coming out of the selector valve. Even though the hi-pressure pump comes on and goes off after a second or two, it does not seem to be pushing fuel up the line like it is suppose to. I guess I need to check fuel pressure somewhere up stream from the hi-pressure pump. Question though, if these pumps turn off after a second or two after turning the key, when you are driving, how does fuel continue to be pumped to the fuel rail. Do the tank pumps only work one time at initial start up to prime selector valve and then the hi-pressure pump works continuously from then on? I do not see how when the hi-pressure pump is working continuously the tank pumps are not as well from the way they all are wired. When the fuel pump relay closes, either tank pump gets energized and always the hi-pressure.

Please give me some ideas and the pressure I should see coming out of the hi-pressure pump. I guess just because I can hear the hi-pressure pump being energized and turning off does not mean it is pumping fuel I guess huh?

Thanks all

Sid

 

There is a safety timer inside the computer and when the key is first turned on it grounds the fuel pump relay coil for one second to help bring up the pressure.
The when the computer sees a PIP pulse from the distributor PIP sensor it grounds the fuel pump relay coil for one more second and every time it sees a PIP pulse.
PIP pulses come faster than one every second when the engine is cranking or running so the pumps selected will run all the time the engine is cranking or running.

To run the selected pumps contuinsly for a test with the engine not running you ground pin #6 of the self-set plug or short it to pin #2 of the self-set plug and turn on the key.

You will not get much fuel out of the high pressure pump unless it is running. If it is running the pump should put out 100psi into a blocked head.



/

 

Ok Bill. What I was saying was that fuel does come out while the hi-pressure pump runs for a second but not at any good pressure or any better than what is being supplied to it I'm thinking. How can I measure the pressure? I see a little valve that is on the rail of the drivers side side of the motor near the front of the engine. Can I check the pressure there while cranking the engine even though it will not fire? Can I use a bicycle air pressure gauge perhaps? The fuel pressure regulator, is it at the rear of the engine right next to the back of the plenum? It is connected to the fuel rail and has a red plastic vacuum line going to it. If this regulator were bad, could this give be bad start up pressure? After cranking the motor 2 or 3 times it will fire but dies right away. Its like it needs to have 2 or 3 cranks worth of fuel put up to the rail to start and then is not getting that fuel continuously to run. If checking the fuel pressure at that little valve that I explained is after the regulator will that be checking the hi-pressure pump or the regulator or both? How can I eliminate the regulator? Or eliminate the distributor for that matter? Lastly, what do you mean by a blocked head? The pumps will all run while shorting pin 6 to to pin also. I certainly do not think 100 psi is coming out of the hi-pressure pump while it is running. But I do think the in tank pumps are doing what they are suppose to as far as pressure goes.

Thanks Bill.

Sid

 

Yes you can check the pressure there with it not running. Just ground pin #6 of self-test connecter and turn on the key

Some have used a tire gauge and say it works but other have had trouble getting them to work.
Some auto part stores will rent you a gauge.

Yes but that does not sound like your problem as the fuel has to get to the fuel rail before the FPR can play with it.
Sounds like you may have a bad high pressure pump.


The "little valve" is between the high pressure pump and the FPR (regulator).
No you can not eliminate the regulator or the distributor.
The FPR would have to be stuck open to give fuel pressure lower than starting pressure (about 28psi).

 

Ok. I put a pressure gauge on that small valve on the fuel rail as we discussed. With the key off it was somewhere like 22 psi. The minute I turned the key it went right to 40-42 psi and stayed there while I cranked it. When I turned the key off the pressure reading dropped to like 30 psi. Turned the key and it went right back to 40-42 psi. Still no fire though. Could it be that my injectors are not firing if fuel is getting to that valve? But it'll start for a second and die sometimes. If the injectors were not firing why would it start at all? Now I am really stumped. I was thinking faulty hi-pressure pump too until I saw the psi jump to 42 psi and stay there as long as the key was turned.

What now?

 

I have no spark on either back plug I checked. I took the distributor cap off and looked at it as well as pulled the rotor. They both look new with no burn marks or typical wear look on either part. If it were wires I highly doubt I'd get no spark on either of the plugs. I've been reading a bit since we spoke last. I see the next thing is a coil or possibly a TFI sensor? Not sure what or where that is. How can I choose between the two of which could be the problem? Another question. Why if I've had fuel pressure to the rail the whole time and no spark, why are the plugs not soaking wet from fuel? the plugs are in really good shape too. Not black or wore at all. Just dry.

Thanks Bill

 

Does the fuel pumps run while the engine is being cranked?
If not it sounds like maybe you have a PIP sensor inside the distributor.
If the computer sees no PIP pulse it will not fire the injectors and of course you will have no spark either or most of the time.
But the fuel pumps will only run then each time the key is turned on for one second and not while cranking if there are no PIP pulses.

 

Can I listen to the hi-pressure pump or either of the tank pumps while SHE cranks the motor? If this PIP sensor is going or is bad, is that why you think my plugs are dry after all this cranking and fuel pressure at the rail? I'll be right back with an answer to your fuel pump running question. Should the pumps run while the engine is being cranked?

 

You might be able to or you can put your hand on it and feel if it is running.

Yes.

Yes.

 

Well it was definitely hard to hear if the hi-pressure pump was running while cranking the motor so I did have my fingers on it. It definitely does not run while engine is being cranked. You thinking PIP sensor then? I have seen where you say it is under the stator in the distributor. Any other checks I can do to be sure about this sensor? Can I just buy the sensor from somewhere and install myself or is the whole distributor needed? I have removed many distributors from cars before but never a van. Is it terribly difficult to remove this one in this 1990 E250 with the 302 do you think? Anything I should pay close attention while doing this sensor replacement? typical cost for the sensor and a place to purchase maybe sir?

Gotta go treat my assistant ignition key operator to dinner for all this.

Thanks Bill

Sid