Do I need PCM??

[JCaron]

Hi, just bought a 93 (I think) cummins for a project I'm building. I'm new here but I have seen posts regarding a PCM. Do I need one?? If so where can I find one? Also I have a 2003 HO 2500, I was thinking maybe I could upgrade some parts on that engine and transplant the parts on to the 93. Any ideas?? Thanks, Jerry

 

[dpuckett]

To run the engine, you wont need a PCM, just a wire going to the fuel shut off solenoid. You will need a voltage regulator- I'd stick with OEM for the vehicle it's going into.



I'd keep the 03 parts off the 93. Bout all that would fit is the turbo, and it's so tiny, you'd take a big step backwards, unless you plan to remain ABSOLUTELY stock. On second thought, the exhaust would be a good cheap upgrade if you upgrade the 03.



Daniel

 

[Philip]

What is the truck doing that make you think it needs a PCM.



Give us some problems to work with.

 

[PToombs]

What's a PCM? :-laf Poorly Controlled Midget? :-laf Oo.

 

[JCaron]

I have not started the engine yet, it is still sitting on an engine stand. It did not come with a PCM and i wondered if it would run without one. Sorry for the confusion, Jerry

 

[Philip]

Ok now its clearer.



All you need to do is supply power to the fuel soleniod and it should start and run. PCM isn't needed for that.

 

[1stgen4evr]

PCM- Politically Correct Mistake



James

 

[JCaron]

OK ,then what exactly is the PCM for? Thanks

 

[PToombs]

It controls alternator charging, grid heaters, dash lites, (like wait to start,etc. ) and I think guages. I could be wrong on some of this, somebody help me!

 

[Philip]

You got most of them Pete.



It also controls the A/C compressor, OD if the truck has a auto.

 

[JCaron]

If it controls all of those things, will I not need one???? It is not going to have an automatic but a working alternator, grid heater, AC and gauges would be nice

 

[PToombs]

If it controls all of those things, will I not need one???? It is not going to have an automatic but a working alternator, grid heater, AC and gauges would be nice

We wouldn't want you to get spoiled! Most of those things can be worked around, boost, pyro, oil pressure, etc, can be, or are manual gauges. Grid heaters can be run off a switch or timed relay. Older alternators only need a regulator, start and run themselves. Get my drift?

 

[Philip]

What are you putting the engine in?

 

[JCaron]

Its going into a M211 deuce and a half.

 

[Philip]

Ok that helps now we know the truck its going in.



You do not need a PCM. Use all the sending units from that mil engine on your B. That will make the orginal gages work. Then just find the wire that was used to fire the orginal injection pump and wire it to VE pump and that should get the engine running. For the alt do a search in the 1st gen forum there are directions on how to wire it up as a pre 91. 5 model to use a exterinal regulator.



I don't have a manual or I would give you the wiring diagram.



Now for AC. Look around this link. Send them a email and talk to them. Most likely they can fix you up with something.



http://www.vintageair.com/



Now the big question. Why such a small engine in that size truck.

 

[Moab4x4]

If you have the wiring harness that came with the engine and are only missing the PCM, Don't worry about not having one. I jumpered two wires in the harness to get the AC to work fine. Pins 27 and 34.

You can run a timer or a push button for the grid heaters if you really need them.

Water in fuel light won't work.

Cruise Control won't work.

Regulator off my 72 Dodge worked great. Wired it as they did in 72.

The guages in the cluster don't need the PCM.

For your app, I agree, 12V to the injection pump don't sweat it.

You have to admit that it is kinda cool having a truck as new as 93 that doesn't require a computer.

OD was on a switch under the dash.



That being said, I got soft and installed the PCM and harness that came from my new donor so I could have cruise.

 

[JCaron]

This deuce only came with a six cylinder gas engine- no power. I think the power potential from the cummins is more than enough to push the old girl. Plus the obvious cool factor with the big knocker and a set of stacks. Also I am shortening the duece and having super single wheels on a single axle for four wheel drive instead of 6 wheel drive. (Should make it quite a bit lighter) Anyways, thanks for all the advice- much appreciated, Jerry