98 Ranger problem! Please Help!!!

[Ranger4x4.0]

I talked to a really good friend of mine, also one of the best mechanics i know. He said it could be one of two things. A camshaft position sensor, or the plugs. Im leaning more toward the cmp sensor. Ill try and get that replaced sometime this week. Any thoughts on the cmp sensor?

 

[black_demon69]

I talked to a really good friend of mine, also one of the best mechanics i know. He said it could be one of two things. A camshaft position sensor, or the plugs. Im leaning more toward the cmp sensor. Ill try and get that replaced sometime this week. Any thoughts on the cmp sensor?

Yes get the codes first

 

[Ranger4x4.0]

Okay, I got 2 codes. P0171 and P0174. Something to do with the fuel, maybe y'all can help!

 

[aspevacek]

troubleshootmyvehicle.com/ford/4.0L/troubleshooting-P0171-and-P0174-page-1

follow this link and the tests they have I think you will have your issue solved and they explained it a lot easier then I could have.

 

[shane96ranger]

Lean on both banks is what those codes mean. You are getting unmetered into the motor. You'll want to start by cleaning the MAF because a dirty MAF can definitely cause this. If that doesn't do it the next search, and most probable cause, is a vacuum leak. I didn't catch the year on your truck, but the plastic upper intakes always like to leak from the upper to lower gaskets.

 

[Ranger4x4.0]

Okay, but would that cause the engine to buck like it does?

 

[Big Jim M]

More than any other problem! AND might burn valves and pistons! VAc leaks are lots more involved than most think. Too much air makes for a really HOT fire.
Think of a cutting torch. To make it hotter we add air (oxygen). Same applies to mixture inside engines.
Big Jim

 

[enjr44]

Lean on both banks is what those codes mean. You are getting unmetered into the motor. You'll want to start by cleaning the MAF because a dirty MAF can definitely cause this. If that doesn't do it the next search, and most probable cause, is a vacuum leak. I didn't catch the year on your truck, but the plastic upper intakes always like to leak from the upper to lower gaskets.

And unmetered air is ANY air getting into the engine after the MAF and that means anywhere. Anything leaking between the air filter and the last O2 sensor can cause those codes. It means the computer is having trouble maintaining the 14 to 1 air to fuel ratio. The MAF measures air into the engine and the computer adjusts injector pulse time to add a pound of fuel for each 14 pounds of air (as measured by the MAF). Lean means the O2 sensors are measuring more unburned O2 in the exhaust than the computer can compensate for.

 

[97RangerXLT]

A common cause of the two codes you listed is the gasket between the lower intake and the fuel rail. it is a paper gasket and part of it that is between the ports disintegrates causing air to go through the gap and make the two cylinders affected burn lean.

There is a TSB out for the 1997 4.0 for this problem, and being a 98, you might have got one of the left over gaskets from 1997.

it is a bit of a chore to remove all of the stuff to get to it, but if you are willing or have a friend who is capable, here is my write up on how to change the gaskets.

http://www.therangerstation.com/forums/showthread.php?t=94437

AJ

 

[97RangerXLT]

Here is the TSB for the 1997 4.0.

http://rockledge.home.comcast.net/~rockledge/RangerPictureGallery/FuelSupplyManifoldGasketTSB.pdf

When I did the upper/ lower gaskets on my Ranger 5 years ago, the fuel rail gasket was just starting to pull a part between the ports. and since you will have most of the stuff removed to get to this gasket, I would go ahead and do the valve cover gaskets and the lower intake gasket and fuel injector o-rings as well.

AJ

 

[97RangerXLT]

Before you do go and look into the gasket issue, Take a look at Shane's reply a few posts above and clean the MAF sensor. that is quick and easy, and will not put your truck down for several hours/ or a day.

Also go and look for any external vacuum leaks again.

AJ

 

[Big Jim M]

Before you tear it apart to LOOK at a gasket, squirt some diesel starter all around to see if the engine smooths out. anywhere that air is coming into the intake system should be squirted to actually see where, if any, leaks are.
Big Jim

 

[jeremysdad]

And unmetered air is ANY air getting into the engine after the MAF and that means anywhere. Anything leaking between the air filter and the last O2 sensor can cause those codes. It means the computer is having trouble maintaining the 14 to 1 air to fuel ratio. The MAF measures air into the engine and the computer adjusts injector pulse time to add a pound of fuel for each 14 pounds of air (as measured by the MAF). Lean means the O2 sensors are measuring more unburned O2 in the exhaust than the computer can compensate for.

Slightly OT, but thoughts and opinions as to whether those damned intake tube rubbers could be an issue here...someone needs to repop those. Mine are all the dead, but damned if I can bring myself to slather on the silicone...so ugly...

 

[Rex2nr]

The plug on my cylinder 1 fuel injector worked loose and caused a P0171 on my truck. I had just done the head gaskets and I guess I didn't clip the plug down tight. plugged it in and reset the computer- it's been good to go since.

 

[Ranger4x4.0]

I'm sure it's not the maf, I looked at it and it is clean. And if it's those gasket things, how much would it cost for all of that? My dad keeps on insisting its the crankshaft sensor, could it be that?