I am trying to track down a problem my truck is having and it all points to the ECU.So i want to get another one to try,Problem is the one in my truck isn't the original one and i'm not sure if it makes a difference or not..They list 4 different MT ECU's for the 93 3.0 ranger.
Is it possible the one in it isn't the correct one and that could be causing the truck to run EXTREMELY rich? I'll be honest i don't mess with rangers much But i have worked on mustangs for many years. On them if you have lets say a 91 5.0 with a MT it doesn't matter what calibration code ECU "A9L,A9M,A9P,ect" you put in it,the car will run even though they have several different ECU's for that year,even an automatic ECU will work with no problems.They just have slightly different fuel/timing tables.

I am fighting a losing battle with this truck it seems..The motor runs like a champ aside from it kicking a 137 and a 173 code.I have checked/replaced everything except the ECU.

Thanks
Steve

 

How do you know that the ECU isn't the original? If it's not, then you have to wonder why the previous owner would have changed it...

How about the MAF sensor, have you tried cleaning it?

Is the engine the original? Sometimes a FFV 3.0L is swapped in and they are equipped with larger fuel injectors from the factory. It's a longshot since you say yours runs OK (usually it will runs so rich as to cough and smoke).

 

The ECU has yellow writting on it like a JY uses,so that leads me to believe it isn't original.
I put a brand new MAF on it as well as cleaned the original stock one..

The engine isn't the original,the guy i got the truck from said they replaced it with one out of a aerostar.I did think about FF injectors but the ones in the truck are grey,just like all the other 14# injectors i have seen..

The ranger runs pretty good but it smokes black and does idle rough.if i hold the RPM at say 2500 it smoothens right out though..BUt it does act weird if i try to drive it and go WOT,it will turn to 3500-4000 RPM and then it acts like it hits a wall and won't go any higher not like a revlimiter though.When it does this the truck blows out alot of black smoke..

I replaced the O2's,Maf,TPS,ECT,IAT,checked O2 wiring,replaced the intake gaskets to be 100% it wasn't an internal intake leak.plus it had a slight oil leak on the back of the intake so i had to have it off anyway..

Thanks
Steve

 

Fuel pressure OK (regulator maybe)?

Sounds like you've been busy on this.

 

Sorry for the delay i haven't had alot of time to mess with the truck lately..But i did check the fuel pressure and it's fine.I thought it was a bad FPR as well at first..

I am going to try to work ont he truck this weekend a little bit,i found another ECU for it locally,hopefully it's the correct part #.their are 3 or 4 different ones listed for a MT 3.0 in 93..i have no idea why...Any insight on that?

Thanks
Steve

 

Pull the vacuum line off the FPR and check for raw gas. The diaphram in them can rupture, pulling raw gas into the intake.....

 

The FPR was one of the first things i checked,I have had them rupture and leak fuel out the vacuum port before..

Thanks
Steve