• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

4.0 running like crap


Tiph92

New Member
Joined
Nov 27, 2020
Messages
3
Reaction score
0
Points
1
Location
Colorado
Vehicle Year
1992
Make / Model
Ford Ranger
Transmission
Manual
I bought a 1992 ranger with the 4.0 back that I owned a few years ago. In that time it had another 4.0 installed right before I got it. It runs like crap. Idles fine, but and soon as you start driving, its popping and stuff real bad. Figured firing order. In the process of checking it, I found the the cam synchronizer on the back of the engine unplugged. Looked all over and couldn't find a connector to plug back into it. Figured it got ripped out or something. Went to the junkyard today and found a 1992 explorer that I went to pull the harness on and found that it doesn't have the cam sync on the engine. My guess is they installed the wrong year 4.0 and now I need to now whats my best option to make it run? Harness and ecu from a engine that has the cam sync or what?
 


Dirtman

Former Middleweight Moss Fighting Champion
Joined
May 28, 2018
Messages
19,304
Reaction score
13,326
Points
113
Location
41N 75W
Vehicle Year
2009
Engine Type
2.3 (4 Cylinder)
Transmission
Automatic
2WD / 4WD
2WD
Total Lift
It's up there.
Total Drop
It's down there.
Tire Size
Round.
My credo
I poop in the furnace.
The cam syncro is not needed if the current ecu doesn't have the hookup for it. The cam sync was originally a California emissions option. The engine is perfectly capable of running soley off the crank trigger provided your current computer is setup that way. You probably just got a later model (94+) engine or a California engine which again, doesn't matter if your ECU is not setup for a cam sensor.

The problem would be if you did the opposite and installed an engine with no cam sensor into a truck with an ECU setup for a cam sensor.
 

Tiph92

New Member
Joined
Nov 27, 2020
Messages
3
Reaction score
0
Points
1
Location
Colorado
Vehicle Year
1992
Make / Model
Ford Ranger
Transmission
Manual
Thank you for the reply.

Best I can tell, they left the factory 1992 harness and ecu in the truck. Doesnt appear any of that has been changed.
Only difference I could find is it having the cam sync now.
So, I take it the teeth on the crank trigger are the same and didn't change between the cam sync engine and non cam sync engine?
Just trying to get this problem narrowed now, its a nice truck and I'm excited to have it back, but now I want to drive it lol
 

Dirtman

Former Middleweight Moss Fighting Champion
Joined
May 28, 2018
Messages
19,304
Reaction score
13,326
Points
113
Location
41N 75W
Vehicle Year
2009
Engine Type
2.3 (4 Cylinder)
Transmission
Automatic
2WD / 4WD
2WD
Total Lift
It's up there.
Total Drop
It's down there.
Tire Size
Round.
My credo
I poop in the furnace.
Crank trigger and gear is the same for both engines. All the cam sensor did was give the computer a bit more data to add a marginal amount of extra control over the ignition timing and fuel trims. With your symptoms I'd be more inclined to start by checking fuel pressure, look for vacuum leaks, and check the plugs, wires, coil packs.
 

RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,292
Reaction score
8,297
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Yes, they swapped in a later model 4.0l and didn't swap oil pump drive in to replace cam synchro, which is fine

If cam synchro starts to squeal you will need to replace it with just the oil pump drive, no timing needed

Because its a pre-1995 and has the 60-wire OBD1 computer, I would pull out the computer and check the 3 blue capacitors inside it, these leak/fail after 20years and cause all sorts of engine issues, there is no "aha, thats the problem" when caps start to fail
$5 fix to replace them
And ALOT of chasing your tail if IT IS the caps and you don't look first, lol

Coil pack wiring is
3 4
2 6
1 5
front

the 5 6 4 side gets me most times, either at the coil or at the cylinders
So trace each spark plug wire, one at a time, to its cylinder

And on any 4.0l.............Clean the MAF sensor, once a year, easy to do
 

Tiph92

New Member
Joined
Nov 27, 2020
Messages
3
Reaction score
0
Points
1
Location
Colorado
Vehicle Year
1992
Make / Model
Ford Ranger
Transmission
Manual
Thank you everyone for the quick replies. Now that I know the cam sync is a non player in this, I can start looking elsewhere for problems.
 

Fast Eddie

Well-Known Member
U.S. Military - Veteran
Joined
Oct 22, 2020
Messages
1,908
Reaction score
2,654
Points
113
Location
On The Road
Vehicle Year
2004
Make / Model
Ranger Edge
Engine Type
3.0 V6
Transmission
Manual
2WD / 4WD
2WD
Total Lift
2x4 on 4x4 Factory Chassis
Tire Size
235/75/15
Yes, they swapped in a later model 4.0l and didn't swap oil pump drive in to replace cam synchro, which is fine

If cam synchro starts to squeal you will need to replace it with just the oil pump drive, no timing needed

Because its a pre-1995 and has the 60-wire OBD1 computer, I would pull out the computer and check the 3 blue capacitors inside it, these leak/fail after 20years and cause all sorts of engine issues, there is no "aha, thats the problem" when caps start to fail
$5 fix to replace them
And ALOT of chasing your tail if IT IS the caps and you don't look first, lol

Coil pack wiring is
3 4
2 6
1 5
front

the 5 6 4 side gets me most times, either at the coil or at the cylinders
So trace each spark plug wire, one at a time, to its cylinder

And on any 4.0l.............Clean the MAF sensor, once a year, easy to do
One word - Yes.
 

rusty ol ranger

Im a Jeep guy now.
Supporting Member
Joined
Sep 22, 2007
Messages
12,267
Reaction score
7,274
Points
113
Location
Michigan
Vehicle Year
1987
Make / Model
Ford
Engine Type
2.9 V6
Engine Size
177 CID
Transmission
Manual
2WD / 4WD
2WD
My credo
A legend to the old man, a hero to the child...
If it idles good but goes to popping and sputtering when you try to take off id be checking fuel pressure first.
 

Sponsored Ad


Sponsored Ad

Members online

Today's birthdays

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Latest posts

Truck of The Month


Kirby N.
March Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top