So i bought a 1987 ranger 4x4 5"lift 5spd FM145 a couple days ago and it is acts strange but i bought it this way.

everything is random and there is no real rythym to it.

-it sometimes has a slight hesitation at idle and may eventually die.
-if it doesn't die it idles around 1k
-if it does die it starts right back up ( it is easy to start, almost click start)
-sometimes while driving it will lose almost all power and seems like its barely running and almost as if its running on just half its cylinders. and when it does this when i pull over it will usually die but when I go to start it back up it starts up no problem and acts normal.

the truck likes the higher rpms. but will stop around 4.5k and cant really go higher.
Ive noticed if i keep it above 2750 rpms it wont lose power while driving and it has the most power. so in while in 4lo is when it best behaves and thats mainly all that i have it in.

I am thinking it is the MAP sensor or the TPS sensor and was wondering if any of you geniuses have already had this situation and I dont need to figure it out by buying a bunch of electrical parts i dont need

 

Why take guesses and/or throw parts at it when you can just ask the computer itself? Pull the codes, here's how:

Ford Ranger - Testing EEC-IV Equipped Engines

 

Actron Code Scanner for Ford CP9015: Advance Auto Parts

will this do the trick ?

 

I don't know, my guess would be "probably yes" but it tells you the codes via a series of flashes, you can do the exact same thing with a $5 testlight from Harbor Failure.

Whatever method you choose, you need to understand that there are three sets of codes in OBD1 systems:

- KOEO - Key on, Engine Off - tests the vasic integrity f the computer, wiring & sensors at the time of the test. If any sensor is failing on that test, it will tell you there else it will give a Code 11 (which is System Pass).

- CM - Continuous Memory - what the computer remembers about the past N driving cycles

- KOER - Key on, Engine Running - The computer will perform some basic manipulations of the engine and report any errors it encounters at that time. Engine needs to be warmed up before doing this test.

The flashing lights error display works just fine so long as you know how to interpret what it's telling you and can count.

It is sometimes easier to go to a parts store and have them pull the codes but you'll be at the mercy of the operator and his knowledge of OBD1 and how well he knows how to use his scanner... it *should* prompt him in the KOER test to, for example, goose the throttle pedal at a specified time (which I combined with turning the steering wheel half a revolution and stepping on the brake pedal, some OBD1 systems are aware of certain aspects of those two systems and will fail KOER if you don't do the test correctly.

Here is a link to one of my albums on Photobucket that contains the FoMoCo instructions for performing these tests, including interpreting the flashes... hopefully, you can read everything OK....

Ford EEC-IV Quick Test by ctubutis | Photobucket

 

Will a bad map sensor give a code? I got a pass code (111) on KOEO test, but then ran KOER and got codes 311 and538. The truck seems to be shifting harder than usual and kind of hangs up before shifting from 2nd, 3rd and 4th. Any help is appreciated. I have the 5.8 efi in a 93 F-150 4X4.

A.G.

 

A failing MAP/BARO sensor will give a 126 code in KOER and it looks like there are a couple of others that can show up in CM.

311 is a problem with the Secondary Air Injection (AIRB/AIRD) Solenoids, I'm guessing you removed the AIR (aka smog) pump?

https://www.motorcraftservice.com/pu...15/VT16026.HTM

Regardless, this wouldn't have anything to do with your problem.

~~

538 is the Dynamic Response Test aka Operator Error, you didn't perform the test properly and goose the throttle/turn the wheel/step on the brakes when it told you to... will not cause your problems.

~~

MY 1993... do you have a computer-controlled E40D transmission? I don't remember when that came out....

EDIT: No, you probably don't, I think that came with the OBD-II system only (started in 1996/97 or so).

 

I bought this truck new in 93, it is stock, still has the smog pump and all emissions junk that came with it. The tranny is an E4OD, that was replaced with a Ford rebuild in 2006. It hasn't given me any problems until lately, replaced egr, IAC, EVP sensor and a major tune up. I'm assuming it's electronically controlled - right?

 

You have a computer controlled engine and a computer-controlled transmission, but it sounds to me like you need to determine if your problem is caused by the engine or the transmission (sounds more like the transmission to me).

If it were me, I would operate on the premise that the Code 311 thing isn't related to your shifting issues... do some investigation on how to diagnose the E40D, all I know is a flashing OD lamp indicates a problem and a special code reader is needed to pull those codes.

Troubleshooting the E4OD and 4R100E Transmission

 

Thanks ctubutis. The OD light does not flash on and off. When I do turn it on you notice the rpms rise - so it works. When I start off I have a loud fan clutch roar and an abrupt shift as it gains speed. It seems to lessen up as it warms up but the throttle is hanging up and you have to let off a bit for the tranny to shift to next gear - mostly from 3rd to 4th gear. A.G.