4.9 question
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1st Gear
Joined: Oct 2022
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4.9 question
Good afternoon,
Looking for some help, I have a 66 econoline shorty van that the previous owner put a 300 4.9 out of a 1988 f150 in. It was running fine one day then out of the blue she has a rough idle and when applying throttle if you go to fast it bogs down and almost dies. She is drivable if you apply throttle very slowly. I have replaced the following list of parts in the last week:
In line fuel pumps x2
in line fuel filter
Map sensor
idle air control valve
TPS
ignition control module
cap
rotor
plugs (#1 plug was clean and nice all other plugs where black and covered in carbon)
plug wires
coil pack
fuel pressure regulator
air filter
Also when starting for the first time of the day it will not fire until I use starting fluid. I will be checking fuel flow at the soft line that conects to the fuel rail area tomorrow and also will be pricing injectors. Will be checking timing as well.
This is an AZ van that sat for a few years but with a battery fired up in July and drove fine until last week. She is now at 6800 feet in the mountains of New Mexico.
Any tips for advice would be greatly appreciated.
Simon
Looking for some help, I have a 66 econoline shorty van that the previous owner put a 300 4.9 out of a 1988 f150 in. It was running fine one day then out of the blue she has a rough idle and when applying throttle if you go to fast it bogs down and almost dies. She is drivable if you apply throttle very slowly. I have replaced the following list of parts in the last week:
In line fuel pumps x2
in line fuel filter
Map sensor
idle air control valve
TPS
ignition control module
cap
rotor
plugs (#1 plug was clean and nice all other plugs where black and covered in carbon)
plug wires
coil pack
fuel pressure regulator
air filter
Also when starting for the first time of the day it will not fire until I use starting fluid. I will be checking fuel flow at the soft line that conects to the fuel rail area tomorrow and also will be pricing injectors. Will be checking timing as well.
This is an AZ van that sat for a few years but with a battery fired up in July and drove fine until last week. She is now at 6800 feet in the mountains of New Mexico.
Any tips for advice would be greatly appreciated.
Simon
Hotshot
Joined: Jun 2015
Posts: 12,871
Likes: 2,445
It’s a little harder to diagnose something when it has been swapped into another vehicle. Did the PO install everything from the ‘88 into the van? Is there an EEC-IV test connector to check for fault codes? The ‘88 would have had a low pressure pump in the gas tank feeding the high pressure pump on the frame rail. The fuel rail has a schrader valve. That is where you check for fuel pressure. With the poor quality of new parts, you really need to stop throwing parts at it. Since none of that has fixed the problem you are replacing good parts with unknown parts and could be making things worse.
Tuned
Joined: May 2019
Posts: 480
Likes: 141
From: NJ
Ugh, EEC-IV systems age terribly to begin with, and now it's all been swapped into an environment is wasn't designed to live in. Good luck, you'll need it. You might have 3 different problems all masking each other.
With the sudden appearance of the problem, I tend to suspect either an electrical problem with the fuel pumps, or a high-side ignition issue. In addition to what the guy above said, I would rig up a fuel gauge I can watch while driving under load.
You should put a Brazil Diesel in it and call it a day. In the unlikely event they don't run, you can diagnose the problem with hammers and pieces of string.
With the sudden appearance of the problem, I tend to suspect either an electrical problem with the fuel pumps, or a high-side ignition issue. In addition to what the guy above said, I would rig up a fuel gauge I can watch while driving under load.
You should put a Brazil Diesel in it and call it a day. In the unlikely event they don't run, you can diagnose the problem with hammers and pieces of string.
Hotshot
Joined: Jun 2015
Posts: 12,871
Likes: 2,445
An ‘88 E-Series van got the exact same drivetrain as the pickup. Being in an old van shouldn’t matter. I suppose the aging thing is relative. Ford didn’t expect or want you to be using the same vehicle 30+ years later. I didn’t have any driveability problems with mine. Rust yes but no drivetrain issues. Or it could be the one fuel pressure problem. We don’t know yet.
Lead Driver
Joined: Jun 2021
Posts: 5,221
Likes: 805
Huh? An ‘88 E-Series van got the exact same drivetrain as the pickup. Being in an old van shouldn’t matter. I suppose the aging thing is relative. Ford didn’t expect or want you to be using the same vehicle 30+ years later. I didn’t have any driveability problems with mine. Rust yes but no drivetrain issues. Or it could be the one fuel pressure problem. We don’t know yet.
An ‘88 E-Series van got the exact same drivetrain as the pickup. Being in an old van shouldn’t matter. I suppose the aging thing is relative. Ford didn’t expect or want you to be using the same vehicle 30+ years later. I didn’t have any driveability problems with mine. Rust yes but no drivetrain issues. Or it could be the one fuel pressure problem. We don’t know yet.
FTE Legend
Joined: Nov 2015
Posts: 30,935
Likes: 4,124
From: Angier, NC
My guess being he posted in here that everything from the 88 van was swapped into his 66 truck so anything used to trouble shoot this issue when in the 88 van would work here too.
One of the first things to do because it has a computer is to pull the codes to see what it sees as wrong.
That should have been done before throwing parts at it as was said because they are new dose not mean they are good.
On that you could have found the bad part but replaced another part with a bad and be in the same boat.
The other thing that worries me is the truck sat a while.
Was the fuel system pulled and either cleaned or replaced before being put back into service?
That 1 clean plug could be 3 things.
A bad injector because of a plugged fuel system from bad gas from sitting.
Bad wiring to that injector from computer.
Computer could also cause this. Pop the cover and check the caps if they popped, a known issue.
A vacuum leak at the head to manifold.
Again pull codes and see what it has to say.
Good luck
Dave ----
One of the first things to do because it has a computer is to pull the codes to see what it sees as wrong.
That should have been done before throwing parts at it as was said because they are new dose not mean they are good.
On that you could have found the bad part but replaced another part with a bad and be in the same boat.
The other thing that worries me is the truck sat a while.
Was the fuel system pulled and either cleaned or replaced before being put back into service?
That 1 clean plug could be 3 things.
A bad injector because of a plugged fuel system from bad gas from sitting.
Bad wiring to that injector from computer.
Computer could also cause this. Pop the cover and check the caps if they popped, a known issue.
A vacuum leak at the head to manifold.
Again pull codes and see what it has to say.
Good luck
Dave ----
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