7427 MPFI+MAF Setup

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Topic author
WT91
Posts: 229
Joined: Thu Jul 02, 2015 12:00 am

7427 MPFI+MAF Setup

Post by WT91 »

The details are in the title, has anyone here made the successful jump from a 7427 TBI setup to either/or a 7427 MPFI/TBI+MAF system? I am starting to get the TBI dialed pretty good and wanted to go MPFI, edelbrock makes a MPFI intake manifold for my motor so when I did the motor build I used the stock cast iron to save $ while we tuned out the bugs. I know the basics of converting the PCM to run 8 injectors vs 2, I'm just wondering if anyone had any real-life advice to add? I'm also looking to convert from speed density to a MAF based system either before or after the MPFI switch, so any advice in that area would be great as well.
:-bd
  • 1990 Grand Wagoneer
    440 swap, 727 MVB, NP208, D44 F/R 4.10 gears ZIP locker up front Detroit out back. So much other stuff. Check out the build.
  • 1994 Ford F350 Crew Cab Dually
    7.3 PS, ZF5, 6.0 Intercooler, KC Turbo

FSJ Guy
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Re: 7427 MPFI+MAF Setup

Post by FSJ Guy »

There is a write up on gearhead-efi.com IIRC.
Ethan Brady

http://www.bigscaryjeep.com

Jeepless, but I still have a lots of old parts in my garage!

Topic author
WT91
Posts: 229
Joined: Thu Jul 02, 2015 12:00 am

Re: 7427 MPFI+MAF Setup

Post by WT91 »

I will have to dig around more, I saw plenty of theory discussion but no legitimate writeup. I have read and re-read the MPFI discussions on binderplanet, but none of them talked about incorporating the MAF.
  • 1990 Grand Wagoneer
    440 swap, 727 MVB, NP208, D44 F/R 4.10 gears ZIP locker up front Detroit out back. So much other stuff. Check out the build.
  • 1994 Ford F350 Crew Cab Dually
    7.3 PS, ZF5, 6.0 Intercooler, KC Turbo
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babywag
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Location: Land of Fruit Loops & Coconuts

Re: 7427 MPFI+MAF Setup

Post by babywag »

To my knowledge on an AMC, I don't believe so.
I haven't seen that setup. I've done just TBI+MAF.
There is a info about MPFI+MAF on several other engines though.

If you search for OD MAF MPFI it should bring up some threads for you.
-Tony
'88 GW (aka Babywag)

Topic author
WT91
Posts: 229
Joined: Thu Jul 02, 2015 12:00 am

Re: 7427 MPFI+MAF Setup

Post by WT91 »

I'm gonna be doing it on the 440 in the Wagoneer.
  • 1990 Grand Wagoneer
    440 swap, 727 MVB, NP208, D44 F/R 4.10 gears ZIP locker up front Detroit out back. So much other stuff. Check out the build.
  • 1994 Ford F350 Crew Cab Dually
    7.3 PS, ZF5, 6.0 Intercooler, KC Turbo
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JeepsAndGuns
Posts: 168
Joined: Sun Jun 10, 2012 4:12 pm
Location: cullman, AL

Re: 7427 MPFI+MAF Setup

Post by JeepsAndGuns »

79 Cherokee Cheif. MPFI 401, T18/D20, hydroboost, otherwise stock.
93 YJ. 4.0, 5 Speed, SYE, hydroboost, WJ knuckles/brakes, 8.8 rear, OME 2.5in lift, warn M10000 winch. 31x10.50's
99 WJ limited. 4.0, auto, 2wd, stock.

Topic author
WT91
Posts: 229
Joined: Thu Jul 02, 2015 12:00 am

Re: 7427 MPFI+MAF Setup

Post by WT91 »

I was hoping you'd reply JeepsandGuns, I read a lot of your posts. Since 2012, have you learned anything new that you would change in your setup? I saw you wired all injectors as left/right banks, didn't use a vacuum FPR, and ran with the neon injectors. I am planning on wiring it the same way, left/right banks, using the LS corvette style fuel filter with built in 58 psi regulator (non vac), and running ford 24 lb/hr injectors out of a DOHC 4.6 V8. My plan is to really understand the system with MAF first, then make the jump to MPFI as that is a less drastic change to the way the system operates.
  • 1990 Grand Wagoneer
    440 swap, 727 MVB, NP208, D44 F/R 4.10 gears ZIP locker up front Detroit out back. So much other stuff. Check out the build.
  • 1994 Ford F350 Crew Cab Dually
    7.3 PS, ZF5, 6.0 Intercooler, KC Turbo
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JeepsAndGuns
Posts: 168
Joined: Sun Jun 10, 2012 4:12 pm
Location: cullman, AL

Re: 7427 MPFI+MAF Setup

Post by JeepsAndGuns »

The neon injectors ended up being too small for my 401. I swapped to corvette LS6 injectors (bosch 0280155931), I am also running a adjustable vacuum referenced fuel pressure regulator set at 45 psi. But this is for my 401. If using a setup similar to this, fuel injectors and fuel pressure will need to be chosen to match your engine size.
The injectors need to be wired as left and right banks, as this is a batch fire system, not sequential.
79 Cherokee Cheif. MPFI 401, T18/D20, hydroboost, otherwise stock.
93 YJ. 4.0, 5 Speed, SYE, hydroboost, WJ knuckles/brakes, 8.8 rear, OME 2.5in lift, warn M10000 winch. 31x10.50's
99 WJ limited. 4.0, auto, 2wd, stock.
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