My '88 BII has been used excuslively for plowing my driveway the last few years. It isn't road worthy by a long shot. When it was last running it would start ok (except in very cold temps) run rough for 10 - 20 seconds and then smooth out. One day it didn't start. I left it sit for a few months before troubleshooting. I quickly determined it wasn't getting fuel. I tested the in-tank pump and it was bad. I replaced it. Still didn't run. I replace dthe pressure regulator. Still didn't run. That's when I found this forum and learned about the high pressure pump. I tested it and it was bad. I replaced it. It started but ran extrememly rough like it was running on about three cylinders. I figured the fuel issues were solved and the rough running was ignition. I put a new cap, rotor and plugs in. It wouldn't start. No fuel pressure again. Double checked the pumps - I could hear the tank pump run and there's voltage to the high pressure pump. There is also now a little gas dripping from the canister before the high pressure pump. I thought this was the fuel filter. Couldn't get it unscrewed. When I put my oil filter wrench on it and tried turning it, more gas squeezed out the top of the canister. Came back to the forum and learned that there's no longer a filter in there - it's downstream of the high pressure pump now. Another thread mentioned that there is still a low pressure regulator in the canister. But I still can't get the canister off. I see where some members have removed the whole unit to get the canister off. Well the first bolt rounded off as soon as I tried to loosen it. Keep in mind this truck is very rusty. I hesitate to start grinding or drilling these bolts with gas leaking from the canister.
Is it likely that the canister/regulator/reservoir thing is the reason it doesn't start? Could a failure there have been what caused the old pumps to have gone bad? Was maybe the reason it started rough because it was initially starving for gas until it ran a while? How the hell am I supposed to get this thing off now? Any help would be greatly appreciated as I can't afford to buy a different plow truck (even a cheap piece of crap) and my bad back doesn't like having to use a snowblower much more than shoveling. I've been fortunate that we haven't had much snow since these problems started, but I know I can't count on that forever
My only thought is to drain the tank and fuel line... or remove the tank completely as gas fumes ignite pretty quickly...and wrap everything with wet rags before you start grinding or drilling...
I had to fabricate a rear sill and support brace across the back end of my BII as the bodymounts had come loose and rusted right thru the rear floor, the sill, and part of the frame...
Since I was working directly over the gas tank, drained the tank, threw a wet blanket over the gas tank with water hose running on it steadily...cut out the rust, and welded up all new metal everwhere...
> Is it likely that the canister/regulator/reservoir thing is the reason it doesn't start?
Unlikely.
You have to check for fuel pressure with a gauge and work backwards from there. Having fixed rusted and salted vehicles, I would say it is very likely two things might have rusted.
The connector for the high pressure fuel pump at the pump.
The connector for the coil. I have had a coil connector "test" good from a back probe, but, be so rusted there was no connection in the front of the connector.
The other thing to check is for a bad relay. They go bad because they are not perfectly sealed and with age they can rust enough, from not being used, so the relay contact does not move.
I forgot to mention two things from the initial troubleshooting since that was over a year ago. It has spark and will start if I squirt gas directly into the throttle body.
When I turn the key on, I can hear the lower pressure pump in the tank and there is 12 volts at the high pressure pump connector. I don't have a fuel pressure gauge, but opening the schrader valve with a screwdriver, no fuel squirts out even if I ground the test connector to keep the pumps running.
I have not changed the fuel filter because until yesterday, I thought the canister was the filter.
When I say there is voltage to the high pressure pump, there is 12 volts across the two pins in the connector. That, plus the fact the timer relay for the fuel pumps is supposed to interrupt the ground, leads me to believe that the pump ground is one of the wires in the connector and not something like a chassis ground.
When I say there is voltage to the high pressure pump, there is 12 volts across the two pins in the connector. That, plus the fact the timer relay for the fuel pumps is supposed to interrupt the ground, leads me to believe that the pump ground is one of the wires in the connector and not something like a chassis ground.
The pump ground is a wire in the connector. I don't know where it went on my BII, but on my Explorer, the fuel pump ground is bolted to the front fender kind of behind the radiator overflow/window washer tank.
Has someone done something unusual to your fuel pump wiring? Every EEC-IV vehicle I've seen has the fuel pump relay on the hot side, with nothing to interrupt the fuel pump ground.
Basically, if the fuel pump is getting power, but not running, there's either something wrong with the ground or something wrong with the pump.
__________________
'87 Bronco II XLT 4x4 & '92 Explorer XLT 4x4 & '98 Chev Suburban K1500 SLT 4x4
> Basically, if the fuel pump is getting power, but not running, there's either
> something wrong with the ground or something wrong with the pump
I agree!
I had a high pressure fuel pump where the connector/stud went bad on the pump from salt that got underneath the boot. So, I drained the pump of gas, took it 1/2 way apart, and resoldered the connector/stud. You can run the pump (not dry) with a jumper too.
"Has someone done something unusual to your fuel pump wiring? Every EEC-IV vehicle I've seen has the fuel pump relay on the hot side, with nothing to interrupt the fuel pump ground."
This is from the service manual for my '92 full size Bronco. I'm assuming the '88 BII works the same way:
"Fuel Delivery Module (FDM) Control
When the ignition switch is turned to the ON position, the Electronic Engine Control (EEC) power relay is energized and provides power to both the fuel pump relay and a timing device in the EEC processor. Fuel pump power is provided through the contacts of the fuel pump relay and the inertia switch. If the ignition switch is not turned to the START position within approximately one second, the timing device in the EEC processor will open the ground circuit (No. 97 T/LG) to the fuel pump relay. Opening the ground circuit de-energizes the fuel pump relay (opening its contacts), which de-energizes the fuel pumps. This circuitry pressurizes the fuel system.
When the ignition switch is turned to the START position, the EEC processor energizes the fuel pump relay to provide fuel while cranking.
After the engine starts, the ignition switch is returned to the ON position, the power to the fuel pump is supplied through the fuel pump relay. The EEC processor senses speed and shuts off the fuel pump by opening the ground circuit,Circuit 97 (T-LG), to the fuel pump relay if the engine stops or engine speed drops below 120 rpm."
So it doesn't actually interrupt the ground for the pump, but the ground for the relay coil.
In any event, the high pressure pump is new and has voltage at the connector so I believed it was running. I will disconnect the in-tank pump and see if I can hear the high pressure pump running and then go from there. Thanks for the replies
"Has someone done something unusual to your fuel pump wiring? Every EEC-IV vehicle I've seen has the fuel pump relay on the hot side, with nothing to interrupt the fuel pump ground."
This is from the service manual for my '92 full size Bronco. I'm assuming the '88 BII works the same way:
"Fuel Delivery Module (FDM) Control
When the ignition switch is turned to the ON position, the Electronic Engine Control (EEC) power relay is energized and provides power to both the fuel pump relay and a timing device in the EEC processor. Fuel pump power is provided through the contacts of the fuel pump relay and the inertia switch. If the ignition switch is not turned to the START position within approximately one second, the timing device in the EEC processor will open the ground circuit (No. 97 T/LG) to the fuel pump relay. Opening the ground circuit de-energizes the fuel pump relay (opening its contacts), which de-energizes the fuel pumps. This circuitry pressurizes the fuel system.
When the ignition switch is turned to the START position, the EEC processor energizes the fuel pump relay to provide fuel while cranking.
After the engine starts, the ignition switch is returned to the ON position, the power to the fuel pump is supplied through the fuel pump relay. The EEC processor senses speed and shuts off the fuel pump by opening the ground circuit,Circuit 97 (T-LG), to the fuel pump relay if the engine stops or engine speed drops below 120 rpm."
So it doesn't actually interrupt the ground for the pump, but the ground for the relay coil.
In any event, the high pressure pump is new and has voltage at the connector so I believed it was running. I will disconnect the in-tank pump and see if I can hear the high pressure pump running and then go from there. Thanks for the replies
That's exactly how I understood it to work. I just misunderstood what you meant when you talked about interrupting the pump ground.
In any case it still comes down to seeing if you can determine if the high pressure pump is running or not.
__________________
'87 Bronco II XLT 4x4 & '92 Explorer XLT 4x4 & '98 Chev Suburban K1500 SLT 4x4
Join Our Site - Its free, quick and easy!
