Banjo
Old Mossy Horns
In or close to Alamance County. I have an 88 F-150 that has got me stumped.
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Need a good Ford Mechanic
- Thread starter Banjo
- Start date
It's a FORD!! J/K ha. What's it doing? Maybe one of us here can help....
Banjo
Old Mossy Horns
I replaced all of the fuel components. Fuel tanks, sending units in both tanks, lift pump, injectors, fuel pressure regulator. We had it running for a while but now it just won’t start. It is holding between 36 and 38 psi fuel pressure, but it just won’t fire. It’s in time, we ohmed out the TPS, new plugs, plug wires, distributor and cap. I’m just stumped. And you are right, it is a Ford. Lol [emoji23]
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Does it act like a gas or spark issue? What is your fuel pressure supposed to be? If it's even a few psi low it can cause a no start. Does it have a crankshaft position sensor?
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Banjo
Old Mossy Horns
It does act like a gas spark issue. I replaced the crankshaft position sensor. The fuel pressure should remain above 34, which it is. I just can’t figure it out.
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Sharps40
Old Mossy Horns
Spark check, see if it'll cough on ether/starting fluid. If so, its all fuel related and not electric. 99% betting its fuel or electrical portion of the fuel system.... i.e. not the electrical portion of the tune.
So, I think it should be showing about 45 to 60lbs fuel pressure, check the manual. Too low and it won't start or if it does, not run well.
Double check to make sure your fuel lines are not reversed at the pumps and verify the tank switch is working. Check also, prime with key on and check to see if it has an accident switch for a rear end strike. Finally, if there is a fuel pump relay, make sure it clicks on (you can hear it) when the key is turned on.
So, I think it should be showing about 45 to 60lbs fuel pressure, check the manual. Too low and it won't start or if it does, not run well.
Double check to make sure your fuel lines are not reversed at the pumps and verify the tank switch is working. Check also, prime with key on and check to see if it has an accident switch for a rear end strike. Finally, if there is a fuel pump relay, make sure it clicks on (you can hear it) when the key is turned on.
JoeR
Eight Pointer
Unplug the Spout Connector to see if it runs better. If it does, pop the cover off the PCM. Leaking caps are common on those older units. If not, give us more info on the symptoms. Is it missing spark, injector pullse, both?
Joe
Banjo
Old Mossy Horns
It will fire on starting fluid. I replaced the tank switch on the frame. The fuel lines are correct. I will double check the fuel pressure, I may be wrong. I didn’t know about an accident switch, I will have to look into that.
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I'm with Sharps, 45+ psi sounds right and if so 38 psi won't do. Just went thru this with a Chevy truck with a new fuel pump. The connection at the pump wasn't right causing low pressure.
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Banjo
Old Mossy Horns
It did run better when the spout connector was unplugged. I was wondering about the PCM.
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Don’t some of the older Fords have fuel pump reset switch behind the glove box? Seems like we had an old Bronco II that had some type of reset switch or relay behind the glove box.
JoeR
Eight Pointer
Check the PCM. Don't replace it without popping the cover off first!!! There are a couple of other things that can cause it to run better with no Spout. Check this one first. If you look closely, you can see 2 leaky caps in that pic.
Next would be a magnetized distributor shaft...but check the PCM first.
Joe
Next would be a magnetized distributor shaft...but check the PCM first.
Joe
Banjo
Old Mossy Horns
302cj
Old Mossy Horns
Ignition module
Banjo
Old Mossy Horns
I’m assuming the 302 in your screen name means you know Fords. [emoji3]
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41magnum
Twelve Pointer
for our F150's needs I ask at www.f150forum.com
Your fuel pressure is correct at 35-40 psi.
You said it started on ether,does it stay running on its own after it started?
If so....... I have run into a lot of old Fords that the coolant temp sensor was skewed and would have a hard time starting. Unplug it and it will go full cold and should fire up
Also,that engine doesn’t have a crank sensor
You said it started on ether,does it stay running on its own after it started?
If so....... I have run into a lot of old Fords that the coolant temp sensor was skewed and would have a hard time starting. Unplug it and it will go full cold and should fire up
Also,that engine doesn’t have a crank sensor
Banjo
Old Mossy Horns
It does not stay running when I quit spraying ether.
Mr.Gadget
Old Mossy Horns
How long you had it or was it F.O.R.D. and you just took it home.....
Mr.Gadget
Old Mossy Horns
Any chance you are building pressure but it does not have the volume needed?
Happened when I replaced everything on my Chevy K5 had us stumped.
Happened when I replaced everything on my Chevy K5 had us stumped.
Next step I would do would be to unplug an injector and check for voltage on one side of the 2 pin connector with a test light. If no voltage then you need to track that down to the fuse or relay that feeds it. If voltage is present,hook the test light clamp up to a battery voltage source and check for a pulsing ground on the other pin of the connector. Obviously you will have to have someone crank the engine while you watch this.
Banjo
Old Mossy Horns
My son actually bought it a couple of years ago. It was in pieces and we put it all back together. I wish now, that he would have bought a Chevy. LOL
v8stang289
Twelve Pointer
I would follow tarheelshooters advice and make sure the injectors are firing. IIRC, the eeciv computer requires input from the Pickup in the distributor and the TFI module in order to fire the injectors. TFI modules in those years are prone to failure due to exposure to heat. I believe the trucks use batch injection, where all the injectors on one bank fire instead of each firing individual.
And as JoeR said, the ecm's have some age on them and leaking caps are common and can wreak havoc. I've ran into that issue on more than one foxbody. Also check to see if the computer is right for the application.
36-38 PSI is within spec for the fuel pressure, as long as it stays close to that once it's running. And since you have fuel pressure, it stands to reason that the inertia switch, etc are working properly. Does the fuel pressure stay up while cranking? or does it immediately begin to fall.
You said you ohmed it out, but what is the TPS voltage with the throttle closed? If the voltage is somehow way off and the ecm thinks the throttle is wide open, then it will not let the injectors fire while cranking, as it thinks you're trying to clear flooded/fuel issue.
Another thing, which engine does it have? 300, 302, 351? do you have the correct firing order?
300- cw 1-5-3-6-2-4
302- ccw 1-5-4-2-6-3-7-8
351- ccw 1-3-7-2-6-5-4-8
Good luck with it, They're not very hard to work on, but sometimes there are a lot variables to check or eliminate.
-Matt
And as JoeR said, the ecm's have some age on them and leaking caps are common and can wreak havoc. I've ran into that issue on more than one foxbody. Also check to see if the computer is right for the application.
36-38 PSI is within spec for the fuel pressure, as long as it stays close to that once it's running. And since you have fuel pressure, it stands to reason that the inertia switch, etc are working properly. Does the fuel pressure stay up while cranking? or does it immediately begin to fall.
You said you ohmed it out, but what is the TPS voltage with the throttle closed? If the voltage is somehow way off and the ecm thinks the throttle is wide open, then it will not let the injectors fire while cranking, as it thinks you're trying to clear flooded/fuel issue.
Another thing, which engine does it have? 300, 302, 351? do you have the correct firing order?
300- cw 1-5-3-6-2-4
302- ccw 1-5-4-2-6-3-7-8
351- ccw 1-3-7-2-6-5-4-8
Good luck with it, They're not very hard to work on, but sometimes there are a lot variables to check or eliminate.
-Matt
Bean
Eight Pointer
Check the ignition module