Someone please tell me the size allen needed to adjust the mixture screws on an 87 Dakota. I can't see in the deep hole so am just poking and guessing. Not even sure an allen is required, could be a torx.

 

Umm ... Which engine?

I'm not sure there ARE idle mixture screws; it's an electronic feedback carb on both motors that year.

RwP

 

My engine is a 3.9 and I should have said mixture screws, rather than idle mixture and there definitely are two of them. No one would notice them if they did not read or hear about them; they are deeply recessed into little cylindrical stubs and covered with plugs for the intent of keeping people from adjusting them. That might be OK as long as the engine is kept to OEM specs but my engine has 270000 + miles on it and needs some help. And it belongs to ME, not some government bureaucrat.

 

Hey, I'm a government bureaucrat and I resent that!!!

 

The plug is to stop you messing with it since the PCM will set the timing and a properly set throttle cable will set the idle. I have the 94 and someone had removed the plug and turned up the idle. It is a Torx bit I think it is T25. If you need to turn up the idle something isn't working or set properly. It should be around 600-800 running idle and the butterfly should be just closed when it is off. With 270K I'm happy you are keeping it going. Gives me hope.

 

Meamjw - For that, you may need to locate the factory service manual; only 1987 3.9's had carbs. But I'm going to bet, since it's an electronic feedback carburator, that those screws won't help as much as a full rebuild will, since the ECU will tweak a lot of the adjustment capability out.

Onemore94Dak - See my note; you've got a throttle body, and no, the PCM doesn't set timing on the LA 3.9's, but do on the Magnums (like you have). There do be a bit of difference between 1987, 1988-1991 or so, and the Magnum V6's. (I'm not sure when the transition to throttle body and/or EFI happened for the I4; it was still carbed in 1988.)

RwP

 

Thanks Ralph and One More.
I do have a factory service manual but it doesn't answer my question. It explains how to get the plugs out of the hole but not what kind of tool to adjust the screws. There is so much crap in the way any kind of screwdriver has to be extremely short to fit in there.
If I knew for sure what kind of head the screws have I would make a special tool for the job. I tried using an inspection mirror and flashlight but still can't get where I can see all the way down the hole to the screw.
I also have a 94 which has given great service until about five weeks ago when the transmission went out. Unfortunately I have learned used parts for a vehicle that old are nearly impossible to find. I bet I have called 25 junk yards in my region but none had a tranny. Did find some online for around $800 but can find many 2000 and up for $300 or less. That's a bummer!

 

Too bad you're not closer to me; although, 3 speed autos aren't that common, alas. (42RH/44RH are a bit more common, though.)

RwP

 

Thanks Ralph My bad. It may be that your motor has a metric and standard mix of fasteners and fittings mine does.