1999 Ford Ranger 4WD 4.0L with 123K mile Here is the problem:

1) Developed a leak in my radiator and drove the truck 220 miles home, stopping to add water about 6 times.

2) Last stop to add water I had the following happen:

A) Engine starts fine in P or N. Place in gear (D, 2 or 1), engine dies immediately. Place in Reverse no problem.

B) To get truck moving: Place in Reverse, back truck up and then immediately drop into 1. Car then moves fine.

C) To continue driving truck, I have to manually drop down to 1 when coming to a stop. Engine does not die when truck is stopped in 1, and I can start up no problem. However, if I move to P and then try to place in gear (D, 2 or 1) engine dies immediately. I have to do the Reverse trick (see B) to get truck moving.

3) Replaced radiator, but have not diagnosed the engine stalling problem (did the leaking radiator cause moisture to enter somewhere in the system?)

4) Hooked up my scanner and am getting a code P-0320 so I think it is an idle control problem.

5) I disconnected the Idle Air Control (IAC) when truck was idling and engine dies so I believe the IAC is okay.

So my question to all you experienced technos out there: What would be the best procedure to diagnose exactly what is wrong? Start with the Crankshaft Position Sensor and wiring? Could it be the Electronic Control Module (ECM)? Distributer? What do you guys think and how would you begin to diagnose the problem without just throwing parts at it?

Thanks!

 

Won't be crank sensor or engine wouldn't start

Turn on AC and see if idle goes up, it should

On the transmission linkage is the DTR(digital transmission range) sensor, it tells the computer(PCM) to bump up the idle(open IAC valve a bit more) when transmission is put into a gear, like it does when AC is on.
It may be working in Reverse but not Drive

Does your shifter feel loose?
Could be PCM is not getting the message of IN GEAR for Drive, did you try shifting to 2nd directly?

I can't see it related to leaking rad, but that being said if engine bay wiring got soaked then it is possible connector is shorting, but the Reverse/Drive thing would not indicate that

 

Thanks Ron D!!!!

I won't be able to test the truck until tonight, but I do know that the idle speed increases when I turn on the A/C.

You pointed me in the direction of the Digital Transmission Range sensor (DTR) and so I looked up a test procedure. Here is a great link to everything you ever wanted to know about the DTR for 1997 thru 2000 Ford vehicles:

http://atsg.com/atsg/facebook/02-14.pdf

Thanks again and I'll let you know how the DTR testing turns out. Hopefully, that's the problem.......

 

Edit: wrong post