Ranger engine performance issues
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Member
Joined: Mar 2022
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From: Waterloo,IL
Ranger engine performance issues
Hello,
I’m new to the site, and I have a 1999 Ford ranger 4.0 4x4 that I bought a week ago with a hard start. I replaced the upstream left, upstream right, and down stream 02 sensors and the MAF sensor. After start up the vehicle would not idle well and threw a camshaft position sensor circuit fault. I bought the new sensor and pigtail and wired them in. Vehicle still would run extremely rough and wouldn’t idle. However if I unplugged the MAF the vehicle would run better but still misfire. Anyone got any ideas? I’m new to rangers as this is the first one I’ve owned and I’m hoping to daily drive it to work.
I’m new to the site, and I have a 1999 Ford ranger 4.0 4x4 that I bought a week ago with a hard start. I replaced the upstream left, upstream right, and down stream 02 sensors and the MAF sensor. After start up the vehicle would not idle well and threw a camshaft position sensor circuit fault. I bought the new sensor and pigtail and wired them in. Vehicle still would run extremely rough and wouldn’t idle. However if I unplugged the MAF the vehicle would run better but still misfire. Anyone got any ideas? I’m new to rangers as this is the first one I’ve owned and I’m hoping to daily drive it to work.
Last edited by 99-4.0-4x4; Mar 20, 2022 at 09:56 PM.
Welcome to the forum
Just to confirm the 1999 4.0l used a 2 wire Cam sensor, 1998 and older use 3 wire, they are NOT interchangeable, totally different signals, not a wiring thing, just an FYI since you mentioned "pigtail"
When you unplug the MAF sensor the computer changes to "Open Loop" so uses built in tables for air/fuel mix, so not a sign of a bad MAF sensor or good MAF sensor
Check the spark plug wiring on coil pack and follow each wire to its cylinder
3 4
2 6
1 5
front
the 1 2 3 side is pretty straight forward, the 5 6 4 side is the one that gets mixed up, so check it, and then check it again, lol
Its VERY important, to have the right firing order
4.0l eats spark plugs, longest lasting are Motorcraft or Autolite, NGK in a pinch
They have wide gaps, 0.054 is spec
Only use regular OR Double Coating, never single coating, its a waste of money on Ford's Waste Spark system
On the 1999 fuel rails(tubes that feed injectors), there is a Pulse Dampener, at the end of one rail, has a vacuum hose attached, pull off that hose and check it for gasoline, replace dampener if gas is present
Fuel pressure on 1998 and up Rangers changed to 60psi(was 35psi), if you can test it that would be great, or at least change the fuel filter, needs it every 5 years or so
Just to confirm the 1999 4.0l used a 2 wire Cam sensor, 1998 and older use 3 wire, they are NOT interchangeable, totally different signals, not a wiring thing, just an FYI since you mentioned "pigtail"
When you unplug the MAF sensor the computer changes to "Open Loop" so uses built in tables for air/fuel mix, so not a sign of a bad MAF sensor or good MAF sensor
Check the spark plug wiring on coil pack and follow each wire to its cylinder
3 4
2 6
1 5
front
the 1 2 3 side is pretty straight forward, the 5 6 4 side is the one that gets mixed up, so check it, and then check it again, lol
Its VERY important, to have the right firing order
4.0l eats spark plugs, longest lasting are Motorcraft or Autolite, NGK in a pinch
They have wide gaps, 0.054 is spec
Only use regular OR Double Coating, never single coating, its a waste of money on Ford's Waste Spark system
On the 1999 fuel rails(tubes that feed injectors), there is a Pulse Dampener, at the end of one rail, has a vacuum hose attached, pull off that hose and check it for gasoline, replace dampener if gas is present
Fuel pressure on 1998 and up Rangers changed to 60psi(was 35psi), if you can test it that would be great, or at least change the fuel filter, needs it every 5 years or so
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Joined: Dec 2017
Posts: 10
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From: Atl, Ga
You've checked all of the 'tune up' stuff, right? Including new air-filter? And checked all vacuum lines?
Have you seen the spark-plugs? Clean, good wire, if coil- newish, if coil-overs - newish?
Did you check compression in each cylinder? Look at the oil, let some sit, see if any water or coolant present.
If you can check the fuel, same thing - maybe empty the tank and try all fresh, quality fuel.
Have you looked at any PCV or similar systems?
Any codes?
Just to be sure, is that OHC or OHV engine? Gasoline, right?
Have you seen the spark-plugs? Clean, good wire, if coil- newish, if coil-overs - newish?
Did you check compression in each cylinder? Look at the oil, let some sit, see if any water or coolant present.
If you can check the fuel, same thing - maybe empty the tank and try all fresh, quality fuel.
Have you looked at any PCV or similar systems?
Any codes?
Just to be sure, is that OHC or OHV engine? Gasoline, right?
Thread Starter
|
Member
Joined: Mar 2022
Posts: 2
Likes: 0
From: Waterloo,IL
You've checked all of the 'tune up' stuff, right? Including new air-filter? And checked all vacuum lines?
Have you seen the spark-plugs? Clean, good wire, if coil- newish, if coil-overs - newish?
Did you check compression in each cylinder? Look at the oil, let some sit, see if any water or coolant present.
If you can check the fuel, same thing - maybe empty the tank and try all fresh, quality fuel.
Have you looked at any PCV or similar systems?
Any codes?
Just to be sure, is that OHC or OHV engine? Gasoline, right?
Have you seen the spark-plugs? Clean, good wire, if coil- newish, if coil-overs - newish?
Did you check compression in each cylinder? Look at the oil, let some sit, see if any water or coolant present.
If you can check the fuel, same thing - maybe empty the tank and try all fresh, quality fuel.
Have you looked at any PCV or similar systems?
Any codes?
Just to be sure, is that OHC or OHV engine? Gasoline, right?
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