I have a 1989 Ford Ranger XLT with 91,000 miles on it.
Recently the Automatic Transmission has started to not engage when put in drive, unless I put on the emergency brake, leave it in drive and then start my ODB1 Troubleshooter and put it into test mode.
The transmission then engages and run fine until it is taken out of drive. Reverse works fine with no issues and on rare occasions Drive will engage immediately when shifted into.
ODB1 is not showing any problem codes.
Transmission Filter and Fluid have been changed.
Is this a solenoid issue or something more serious?

 

Welcome to the forum

You have an A4LD transmission
It only has 2 solenoids, TCC(torque converter lock solenoid) and 3/4shift(OD solenoid)
TCC is used after speed is above 30mph to improve MPG
3/4shift is used to engage OD if speed is high enough

So no, lack of D engagement is not solenoid related, this applies to ANY automatic of ANY year
Try shifting to 1 and see if it engages immediately?
Also if you raise RPMs in D will it engage faster or at all?


There would be no reason for OBD1 reader to change transmission status, A4LD just has the 2 wires for the 2 solenoids and neither solenoid controls engagement
So thats odd
Solenoids in any year were just used for smoother shifting and improved MPG by selecting the correct ratio for speed and engine RPMs, they are not involved in engagement of the transmission, that's done mechanically by the Shifter
Now the valves operated by the solenoids can leak and thats a loss of Pressure, and Pressure is what engages any "gear"
You need 110psi for Forward
And 160psi for Reverse

Its good Reverse works that means its not a base Pressure Issue, but there could be a leak lowering Pressure in D so it won't engage
But lack of Forward engagement may also point to Sprag(forward one-way clutch) issue which means a full tear down

 

I have tried cycling it through 1 , , 2, OD and N to get it to engage and it doesn't in any of those modes.

I have tried revving the engine to get it to engage and that hasn't made much a difference, occasionally it might engage that way.

Now the ODB1 when test mode is engaged it does Rev up the engine then bring it back to Idle, so maybe that is whats causing it to engage.

I have left the ODB1 on while driving it and it doesn't set any codes per the attached is the ;list of codes it looks for from the transmission.

1989 Ford Ranger XLT ODB1 Transmission Codes

 

Yes, Test mode tests the IAC Valve which raises and lowers RPM

Your 1989 EEC-IV computer should use 2 digit trouble codes not 3 digit

List seen here: https://www.therangerstation.com/tec...gitcodes.shtml

 

This is the Tester I have, INOVA 3145 - Digital Ford Code Reader (1981 – 1995), It's manual is at: https://www.innova.com/Support/Downl...ader-1981-1995

Far as the codes go what confused me was in the manual on page 27 it has Note: Most Ford EEC-IV vehicle computers up to 91 use a 2 digit code system. From 1991 to 1995 use a 3 digit code system.
The word Most confused me as in the list of retrieved codes it had some of the 3 digit codes listed as Trucks Only.

So is it possible then that the IAC Valve could be causing the issue? Or it being revved is possibly an indication of a vacuum leak that might be the cause of issue?

 

No, not IAC Valve or vacuum leak

A4LD does use a vacuum modulator, on passenger side of trans, you can check that hose for ATF(fluid) shouldn't be any of course, but a bad vacuum modulator would show up as shifting issues when moving
As said shifting "in to gear" is a mechanical movement of the shift rod so not effected by solenoids or in this case vacuum

 

Thanks for all the information.
I sounds like it may be time to get it. Is there any value in a 1989 Ford Ranger XLT with 95,000 on it with a transmission problem Has No body rust, engine runs great . Have maintenance records from 1991 when I bought it to present.

 

You would have to look at your local craigslist or trucktrader to get an idea of what its worth in your area, truck prices vary widely by area

Also look at what a rebuilt A4LD for your engine size(there were two, 2.3l and 2.9l in 1989) costs in your area, 1987-1994 A4LD would work, also needs to match 2WD or 4x4 as well as engine size

So you can set a reasonable, "as is" price

 

It's a 2.3L 2WD , live in Pa. Like so many got laid off from work so can't afford to pay to get it repaired so was hoping was something I could fix myself.