Registered: 01/07/19
Posts: 4
Loc: Texas
I am installing a Fitech fuel injection system on my 86 Dodge Ram.

I have removed all of the emissions related parts and installed headers.

Question is what all does the PCM control on this truck? can I disconnect it and remove unnecessary wiring and install orange box ECU with vacuum advance distributor and ballast?

I know there is probably an easier way going to points system or petronix but I already have everything mentioned brand new in box.

any help would be greatly appreciated.

WEEEELLLLLL CRAP! What now? took the wiring harness off of my truck to remove all unnecessary computer wires and after I have all but destroyed the harness, I see it has a relay for the lock up converter. now I have no computer and no wires to reconnect. what are my options, really didn't want to have to buy a new transmission right now.

You could just wire up the relay and put it on a switch. Alternatively you could use two adjustable Hobbs switches and two relays plumbed into the governor port to get lockup.

Before I tore the truck apart it acted like the converter was staying locked up all the time. it would slam into gear even at low idle.(only 155 original hp)

If the converter is bad they usually lockup in reverse and stall the engine. Try driving it without the lockup hooked up first and see how it acts.

you can make your own lockup for the tranny---all you need is a on off pressure switch---pull one off a 80-90's chrysler AC unit---there is a diagram for it on line------basically the hot wire into the 2 plug lead--then the negative wire goes to the pressure port on the other side of tranny where the pressure switch is now installed---then up to your dash where you have an option if a toggle on/off---then ground back to the tranny....PATC has the diagram and explanation online....their switches are expensive----i usually just grab a few at the pick apart----on some foreign cars the same style of switches will actually have the BAR value printed right on them---the mopar AC switch works just fine...

I tried doing this on my 92 that's been converted to lock up with less than stellar results. I had to use an adjustable Hobbs switch though as the governor pressure on a diesel is about twice what the gas engine version is. Anyway when the pressure would reach the trip point the lock up would hunt in and out if you couldn't keep accelerating past that point. Really annoying. Supercuda provided a wiring diaphragm that used two Hobbs switches set to high and low pressure points and two relays so that when the pressure reached the higher switch set point the converter would lock and then would stay locked until the lower pressure switch point was reached. Works like it's factory now. Locks up about 45+/- 1 or 2 MPH and unlocks about 40+/- 1 or 2 MPH.

the pressure switch used by patc is a GM unit used in turbo 350 transmissions-----they charge about 20 times more for it than it costs-----the AC pressure switch turns on at 30 psi and turns off at 20psi (for instance)---this prevents the AC unit fluttering on and off at 25 psi and destroying the unit.....you can find a multitude of psi ranges available-----if you are wiring both lockup and overdrive you want to have the activation points at different spots.....i bought the patc kit for my 64 savoy with a 500 tranny---i was less that thrilled with trying to adjust the vacuum switch they provided---i run without it------i bought a 92 diesel truck with a bad o/d switch---it had been bypassed with just a toggle-----i put the purloined AC switch on it and drove it a year without issue.......

Yeah that switch would work for overdrive but it's too low for lockup.

Got it running. Haven’t drove yet. Have to get exhaust installed.

you guys made me read-----the PATC site shows switch activations between 40 psi to 50 psi (40mph to 50 mph) the allpar site says lockup can be between 27 psi to 31 psi and only locks up when in 3rd gear.......

27 to 31 for lockup isn't too bad in third. Probably still a little luggy depending on final drive ratio and all. But lockup at 27 to 31 in overdrive is a no go.