MPI Conversion

[3Darts]

i hope I have the right person for the MPI conversion question i still have a hard time navigating this site. It is relatively simple and no in tank pump needed. I prefer the return line fuel system. aftermarket holley frame mount pump. plumb the return line into the fuel filler neck. i used an 94 ram truck harness it mounted the pcm where the right inner fender is. if some one wants to know in great detail i am willing to share. 600 for the 93 jeep grand cherokee rollover with 155k (powertrain) 100 for the ram truck harness (pick n pull) 100ish for the holley pump 50 dollars for a 94 360 pcm which worked on the 93 318. excellent power add and fuel economy 35s 4:10 gears 18 mpg highway @ 2000rpm. It is all wiring patients and plumbing and the ability to read and understand a wiring diagram. most fun mod i ever did wiring took 20 hours but it started first time and i ohm checked every wire and ground in the whole harness and removed every unneeded wire to eliminate confusion.

 

[cudak888]

if some one wants to know in great detail i am willing to share.

I believe it's been done before, but I've never seen a complete schematic to splice the Magnum harness into the A-body harness.

-Kurt

 

[3Darts]

I believe it's been done before, but I've never seen a complete schematic to splice the Magnum harness into the A-body harness.


-Kurt

I will save this email it will take some time. I am not sure how to post a wiring diagram on here I am sure my daughter can help with that. I can make one for an A body. I still have the 75 power wagon I did in my head. we did use the 518 automatic. I know how to do it with727 but it involves using a Manuel trans pcm to keep check engine light off. I figured to build a "stock one" then once it runs like ma mopar intended the modifications could begin. basically I laid a 75 truck diagram next to the 93 truck one and made it work. the tricky things o2 sensor placement. extra brake lamp switch( for cruise control)lock up torque convertor and you will have to use a volt meter and bypass stock amp meter because of small dart charge wiring and hi amp alternator. lastly the pass through speed sensor to use stock cable odometer.
if I was to pick an A body to tell I would need to base it on using a 727 because using an over drive tranny requires substantial floor pan modification. please let me know what you would like to see, magnum and 727 A body or magnum and 518 overdrive in the truck I did and it worked ( they would be very similar). how ever you would like to see it will be a "Book". I live in Cali and the truck moved to North Carolina I don't have any photos :-(

 

[magnummopar]

A 5.9 will run better on a 5.2 pcm than a 5.9 pcm. The stock 5.9 has too much fuel and no timing so using a 5.2 which has more timing and a little less fuel runs much better. What was your question?

 

[jbc426]

My Hotwire Auto "Hotrod" EFI harness hooked into my '68 A-Body harness with 4 wires. One was a ground and two hooked to the combined 12v supply of Start 1 and Start 2. I forget where the 4th one attached, but it was super simple and very neat.

 

[magnummopar]

My Hotwire Auto "Hotrod" EFI harness hooked into my '68 A-Body harness with 4 wires. One was a ground and two hooked to the combined 12v supply of Start 1 and Start 2. I forget where the 4th one attached, but it was super simple and very neat.

I would think battery +. We build the same harness and they require Batt, ignition(start/run)+ and ground. Overdrive trans requires an over drive off wire also. Super simple.

 

[jbc426]

Thanks. Yes, I believe it was a 12v+. My overdrive uses an on/off 12v+ that is also switched by a 4th gear pressure switch inside the transmission. It activates a open/closed solenoid inside the transmission. I think the wiring is the hardest part of the swap. There sure are a lot of wires when you first look into this swap. Everything else pretty much bolts right in with the exception of a few minor chassis mod's to fit an overdrive transmission.

Do you guys reprogram the ECM's too? It's amazing how well they work on high performance engines.

 

[magnummopar]

We have guys that do our flashing for us, we can remove emissions, auto trans, rear O2 etc as well as any performance upgrade you make. Funny how so many people here think injection makes less power than a carb. Will never understand why they dont get it.

I have built hundreds of harnesses and sent them all over the world so its no big deal to me anymore. Have most of the wire colors memorized from all the different models and years including the Wranglers which is what we do most of the harnesses for.

 

[Infecteddog]

We have guys that do our flashing for us, we can remove emissions, auto trans, rear O2 etc as well as any performance upgrade you make. Funny how so many people here think injection makes less power than a carb. Will never understand why they dont get it.

I have built hundreds of harnesses and sent them all over the world so its no big deal to me anymore. Have most of the wire colors memorized from all the different models and years including the Wranglers which is what we do most of the harnesses for.

Probably because most using FI use stock for budget reasons and many budget builds are just that- on a budget so cheap as possible is the goal. So often results aren't extraordinary since they don't have a lot of money in the builds. There's not usually too many all-out builds you see for truthfully logical reasons. Usually they get everything back together and if it's not going to be a record-setter which few things are, they want reliability. If it's going to be a street vehicle they want good drivability. So despite some of the radical budget builds proving you really can do it with injection, you simply don't see it done more for individual reasons than superiority of carbs.