Fuel Problem
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Senior User
Joined: Dec 2006
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From: Angier, NC
Fuel Problem
Back in June I bought a 1987 Bronco II that the transmission had been removed from. The Bronco supposedly ran fine before the transmission failed, but I have never seen it run. With all of your help I finally finished replacing the transmission. It had a FM145 and I replaced it with a FM146. I had to torch the rivets in the cross member hangers to move it back for the mount on the FM146, when I did I melted the return fuel line enough to cause a leak. I repaired fuel leak but still no fuel. I bypassed the fuel pump relay and the fuel pump worked. I have 40 pounds of pressure @ the fuel rail. The Bronco fires on starting fluid but will not even try to fire without it.
Any advice on where to look next would be appreciated.
Thanks
<O
</O
Chad
Any advice on where to look next would be appreciated.
Thanks
<O
</OChad
Laughing Gas
Joined: Sep 2005
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Is it getting spark? How about fuel, do the plugs have any fuel on them? If nothing in the fuel department you will need to get your hands on some nodes to see if they are even firing. That could go anywhere from a bad connection to the computer. If no spark it could be the TFI, distributor, wiring or computer related issues there as well. Check you fuses, and all grounds; especially the engine ground.
Matt
Matt
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Joined: Oct 2003
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From: SoCal
If you figure out why the pump relay is not working,i'd bet this thing would fire rght up.
Heres what you should se at the pump relay.
Key on or off the yellow wire at the pump relay should have 12 volts.
Key on & all the wires should have 12 volts.
With key on, if you're not seeing 12 volts on the red, THATS your problem.
With the key on thee EEC relay sends voltage to the pump relay the injectors the computer AND the pump relay on that red wire.
Heres what you should se at the pump relay.
Key on or off the yellow wire at the pump relay should have 12 volts.
Key on & all the wires should have 12 volts.
With key on, if you're not seeing 12 volts on the red, THATS your problem.
With the key on thee EEC relay sends voltage to the pump relay the injectors the computer AND the pump relay on that red wire.
Thread Starter
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Senior User
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From: Angier, NC
Originally Posted by projectnitemare
Is it getting spark? How about fuel, do the plugs have any fuel on them? If nothing in the fuel department you will need to get your hands on some nodes to see if they are even firing. That could go anywhere from a bad connection to the computer. If no spark it could be the TFI, distributor, wiring or computer related issues there as well. Check you fuses, and all grounds; especially the engine ground.
Matt
Matt
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From: Angier, NC
Originally Posted by 87 XLT
If you figure out why the pump relay is not working,i'd bet this thing would fire rght up.
Heres what you should se at the pump relay.
Key on or off the yellow wire at the pump relay should have 12 volts.
Key on & all the wires should have 12 volts.
With key on, if you're not seeing 12 volts on the red, THATS your problem.
With the key on thee EEC relay sends voltage to the pump relay the injectors the computer AND the pump relay on that red wire.
Heres what you should se at the pump relay.
Key on or off the yellow wire at the pump relay should have 12 volts.
Key on & all the wires should have 12 volts.
With key on, if you're not seeing 12 volts on the red, THATS your problem.
With the key on thee EEC relay sends voltage to the pump relay the injectors the computer AND the pump relay on that red wire.
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Senior User
Joined: Dec 2006
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From: Angier, NC
Now with thanksgiving over I am still trying to figure this thing out. I have constant power @ the yellow wire. With key on I have power at the red wire and the tan/light green wire. At no time do I have power at the orange/light blue wire, unless I jump it from the yellow wire which is what I have done to get the fuel pump to kick on and obtain 40lbs on the fuel rail. I have swapped the relay out with one from a donor vehicle (not known to work) but get the same results. I don’t mind the cost of buying a new relay if any of you think that would be worth a try. Any ideas would be great
Thanks
Chad
Thanks
Chad
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From: SoCal
Good job of troubleshooting.
Heres how it's supposed to work.
Turn the key to run & voltage on Red flows thru the pump relay coil to the T/LG.
At the same time the PCM applies a ground to the T/LG.
The pump relay closes & puts voltage on O/LB.
Either the PCM isnt grounding T/LG or theres a break in the wire.
Try this simple little test: With the key turned to run ground the T/LG pin at the self test connector with a jumper wire.
Do the pumps run??
BTW, have you ever tried to pull the codes on this? Did you get at least an 11 "system pass"?
If not, check the PCM ground at the negative battery cable.
Heres how it's supposed to work.
Turn the key to run & voltage on Red flows thru the pump relay coil to the T/LG.
At the same time the PCM applies a ground to the T/LG.
The pump relay closes & puts voltage on O/LB.
Either the PCM isnt grounding T/LG or theres a break in the wire.
Try this simple little test: With the key turned to run ground the T/LG pin at the self test connector with a jumper wire.
Do the pumps run??
BTW, have you ever tried to pull the codes on this? Did you get at least an 11 "system pass"?
If not, check the PCM ground at the negative battery cable.
Last edited by 87 XLT; Nov 26, 2007 at 03:48 PM.
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From: Angier, NC
Now I will show my ignorance. EFI is new to me I am more of an old FE guy. I am not familiar with term PCM. I am not sure what the “self test connector” is. I have been checking for voltage on the back side of the plug that connects to the relay. I will try to ground the T/LG wire. Thanks for the info on how the relay opens and closes. That helps knowing how the relay works. I assumed that the yellow wire closed the relay and supplied power to the T/LG wire. I have never pulled the codes. I should have a code reader anyway. I will pick one up. Are there any suggestions on what type of reader to buy? I assume there will be some instructions with it. I would not even know were to plug it in. but I am sure I can figure it out.
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From: SoCal
The PCM is the brains of the engine controls.
Based on inputs from different sensors the PCM (or ECM same thing) controls ignition timing/injectors/EGR/fuel pump relay, etc.
Call around to some car part stores & see if you can find an Actron CP-9015 scanner for around 30 bucks.
I mention the Actron because I know that it comes with an excellent manual that tells you exactly how to use it & it has a very good section that tells you most everything that you want to know about the PCM & EEC-4 engine controls.
Take a look under the hood in front of the heater blower motor, the 3 wire self test connector (& the single wire connector) will be in this area. On my 87 they are sitting on top of the blower motor.
This is a handy spot for grounding the tan/light green. It's also where you will connect your scanner to pull the trouble codes.
Based on inputs from different sensors the PCM (or ECM same thing) controls ignition timing/injectors/EGR/fuel pump relay, etc.
Call around to some car part stores & see if you can find an Actron CP-9015 scanner for around 30 bucks.
I mention the Actron because I know that it comes with an excellent manual that tells you exactly how to use it & it has a very good section that tells you most everything that you want to know about the PCM & EEC-4 engine controls.
Take a look under the hood in front of the heater blower motor, the 3 wire self test connector (& the single wire connector) will be in this area. On my 87 they are sitting on top of the blower motor.
This is a handy spot for grounding the tan/light green. It's also where you will connect your scanner to pull the trouble codes.
Fleet Owner
Joined: Aug 2005
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From: Easton,Ks
Originally Posted by whitetrash
Now I will show my ignorance. EFI is new to me I am more of an old FE guy. I am not familiar with term PCM. I am not sure what the “self test connector” is. I have been checking for voltage on the back side of the plug that connects to the relay. I will try to ground the T/LG wire. Thanks for the info on how the relay opens and closes. That helps knowing how the relay works. I assumed that the yellow wire closed the relay and supplied power to the T/LG wire. I have never pulled the codes. I should have a code reader anyway. I will pick one up. Are there any suggestions on what type of reader to buy? I assume there will be some instructions with it. I would not even know were to plug it in. but I am sure I can figure it out.
You say it runs with starting fluid so you are getting spark and the PIP signal is going to the computer.
You say you have power on the red wire with the key on so the PCM Power relay is working and you should then have power to the injectors.
Now all you needs is for the PCM Computer to ground the two banks of injectors.
If you put a code scanner on I would bet it would not read at all.
My guess is you have a bad PCM Computer, go to a salvage yard and get one for about $25.00 and stick it in the passenger kick panel.
Fleet Owner
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From: Easton,Ks
Originally Posted by whitetrash
I will be picking up the code scanner today (Actron CP9180). My auto parts store had to order it. I have an 1988 donor Bronco. Will that year PCM work in my 87?
If it is the full size Bronco I would say no.
But on the other hand I would say it would be good enough to test the BII and see if the injectors are working and the fuel pumps work right. If they do work or do not work then you will know if its the computer or not.
Postmaster
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From: SoCal
I had a feeling that the PCM might be shot & what Bill said confirms it.
Thanks Bill.
Looks like the PCM is powering up OK & handling the ignition timing, but it's not pulsing the injectors or grounding the pump relay.
BTW, I took a look at the Actron site & it looks like the CP9180 is for 96 & newer Fords with the OBD-2 only.
I did'nt see any mention that it can also be adapted & used on your B-2 with the EEC-4 system.
Thanks Bill.
Looks like the PCM is powering up OK & handling the ignition timing, but it's not pulsing the injectors or grounding the pump relay.
BTW, I took a look at the Actron site & it looks like the CP9180 is for 96 & newer Fords with the OBD-2 only.
I did'nt see any mention that it can also be adapted & used on your B-2 with the EEC-4 system.
Freshman User
Joined: Oct 2007
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I picked up a Ford Code Reader for my 90 Bronco II on ebay...you can find them pretty cheap...they work fine...comes witha paperback user manual about 100 pages long...
It is a INNOVA EQUUS #3145
For 1981 to 1995 Ford, Lincoln & Mercury Domestic Cars, Trucks, and Vans
McQue
It is a INNOVA EQUUS #3145
For 1981 to 1995 Ford, Lincoln & Mercury Domestic Cars, Trucks, and Vans
McQue
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Senior User
Joined: Dec 2006
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From: Angier, NC
I was being lazy in my typing the 88 is indeed a Bronco II. I purchased it to harvest the needed transmission (5spd fm146). The 88 did not run so I am not sure if the CPM is functional or not.
I was late getting home tonight so I have not picked up the code reader yet. I was told at the auto parts store (by a clerk that looked like he was 12 and new everything) that the CP9180 would work with the older vehicles as well. I wanted that one so I can use it with my later vehicles as well, and if it does not work they have the Actron CP-9015 (for older fords) in stock for 28 bucks. If needed I will just grab that one, although it sounds like from what you all are saying, we have pretty much determined the problem. But I still like buying new tools
I was late getting home tonight so I have not picked up the code reader yet. I was told at the auto parts store (by a clerk that looked like he was 12 and new everything) that the CP9180 would work with the older vehicles as well. I wanted that one so I can use it with my later vehicles as well, and if it does not work they have the Actron CP-9015 (for older fords) in stock for 28 bucks. If needed I will just grab that one, although it sounds like from what you all are saying, we have pretty much determined the problem. But I still like buying new tools