Swapped engine in 98 ranger 3.0 and put in 4.0 from a wrecked 99 ranger. Had to change tranny and exhaust also. The 4.0 will crank but not start. Have spark to plugs have 50 psi at.fuel rail. Checked injector with noid light no injector pulse. Changed pcm with used one same thing no pulse. Tried the 3.0 pcm had pulse but no start. Engine will hit with starter fluid sprayed in throttle body. Checked grounds even added extra one. Do not know what to try next. A ny idea would help.

 

Welcome to the forum

1999 was the first year of PATS, passive anti-theft system, in Rangers, PCM won't turn on the injectors until correct PATS key is used.

In the 1999 PATS version there is a PATS module above glove box, Type B PATS, it tested Key and then gave PCM "thumbs up or thumbs down" for injector start up
PATS module is "married" to the PCM at the factory so they can't be interchanged unless Ford Dealer "remarries" the new piece.
If you still have the wrecked 1999 then you could get the wiring harness for the PATS key transceiver and PATS module, and wiring to PCM and of course a key from the 1999, tape key into transceiver, so PATS gives "thumbs up" each time you try to start engine.

Your best bet is to get a 1998 4.0l Ranger PCM, no PATS
Must match trans and 4WD or 2WD

There is no "by-pass" for PATS, wouldn't be much of an anti-theft system if there was, lol.
There are Programmers that can tune PCM for better performance and/or MPG, and they can also delete PATS check in PCM, don't know how much though

 

Thanks for the help. I have been working on this for a month and probably would not have figured it out without help. I wii find a pcm for 98 ranger 4x4 with auto trans. Thanks again I will let you know if it works.

 

Just a heads up, 1997 or earlier won't work, Ranger got new fuel system on 1998, running 65psi pressure
1997 and earlier runs 35psi pressure, so PCM air/fuel mix is set differently, shorter open time for injectors in 1998 and up.

Also did the Cam position sensor have 2 or 3 wires, 3 wire was used until late 1990's then it was changed to 2 wire.
Totally different sensors, PCM is programmed differently for each type, so cam sensor must match PCM

 

I have been looking for pcm for 98 ranger 4.0 4x4 a/t. Have seen 3 on line but they all had different numbers. Wish I had vin of donor truck. I have friend who works at ford dealership. He had a ford tech call me . He said if I replaced ignition and key from donor truck the pcm would recognize pats and start. I do have ignition and key from donor truck but I thought I would need pats module from behind glove box which I don't have. It will be a few days before I will have time to work on it. Just thought I would let you know what's up with my ranger. Later.

 

Yes, friend is incorrect, you have Type B PATS in 1999 PCM so need the original PATS module
2001 and up Rangers had Type E, no separate module, PCM had PATS built-in

Ford Part numbers are a bit odd in some respects
ALL Ford PCMs have this center number 12A650, this is the generic part number for a ford engine computer

First set of numbers is the year and model
F87Z
F8 is 1998, F9 is 1999, F7 is 1997
7 is Ranger
Z is electronic part

Last 2 to 4 digits like BVA were never decoded by Ford, they are a mystery, lol, but manual or automatic trans could be determined if there was a match

Whole number above would look like this F87Z-12A650-BVA

You current 1999 would be F97Z-12A650-???

You could try using your 1998 VIN but change the 8th digit to X(4.0l), replacing the 3.0l engine code
VIN decoder here: http://www.therangerstation.com/tech...IN_Codes.shtml