efi 5.0 with 2.9 harness

[Boggin]

Found out from a fellow Ranger enthusiast that for the 2.9L to 5.0L swap, solder in 2 more injector plugs and run an 89 F150 ECM. The 2.9L and the F150s are batch fire injection and the pinouts for the ECM were the same. He told me he ran the F150 box just to make sure the pulse-width for the injectors was correct and would not starve the engine for fuel. But he said you could probably get away with using the 2.9L ECM in a pinch.

would this work? if so, my brother has a spare efi 5.0 high output laying around..

 

[freerider6_9]

Yes, it does, I actually did it last weekend. Only takes a couple hours to wire and that was taking my time. I made a new injector harness completly though and had to switch connectors for the tps, and extend my iac wiring but it does work, I also used the 5.0 computer though as with my research the speed density computers are matched to the intake setups(car vs. truck vs. B2 ect.)

 

[red rocket]

well i think im going to give this a shot, what year ecm did you use

 

[dangerranger83]

What year 2.9 can do this (if all awesome) and what years 5.0 will work with this? This info is great to know and should be in the tech library.

 

[waynaferd]

EDIT: nm, I'm starting out with a 4cyl!!

 

[freerider6_9]

I used a 91 f150 ecm, I believe all speed density ecms have the same pinouts though, If you wanted to double check just find the pinout for each ecm. also dont forget the knock sensor plug while you are at the jy getting your connectors.

 

[Teddyzee]

I used a 91 f150 ecm, I believe all speed density ecms have the same pinouts though, If you wanted to double check just find the pinout for each ecm. also dont forget the knock sensor plug while you are at the jy getting your connectors.

I can't recommend this style of wiring, as I've not done it, but remember that the HO ECU's (Mustang/Cougar/TBird/MarkVII, etc.) were all sequential EFI, even on Speed Density cars, so they would not work here.

 

[red rocket]

im in the process of doin it with a 89 2.9 liter, i also have a 92 ecm out of a bronco that im going to try as well, ill let everyone know if it works

 

[1mean02hd]

I used a 91 f150 ecm, I believe all speed density ecms have the same pinouts though, If you wanted to double check just find the pinout for each ecm. also dont forget the knock sensor plug while you are at the jy getting your connectors.

That is true- speed density ECMs have the same pinout. Ford EEC-IV ECMs are tuned/ programmed to use a certain size injector- hence why it's always been said that swapping MAF sensors on a mass air car to compensate for injector sizes is actually "cheating" the computer. This is also the reason why you should use the V8 ECM over the 2.9L one.

And Teddy, you're right, Fox cars (T-bird, Mustang, Mark VII) all run sequential EFI and not batch or bank- fired EFI and cannot be wired this way.

 

[RangerSVT]

I can't recommend this style of wiring, as I've not done it, but remember that the HO ECU's (Mustang/Cougar/TBird/MarkVII, etc.) were all sequential EFI, even on Speed Density cars, so they would not work here.

To make it a little clearer for everyone, the HO wiring harness can not be used for this swap, you must use the engine harness from trucks and vans, the non-HO motors/harnesses...
SVT

 

[freerider6_9]

To make it a little clearer for everyone, the HO wiring harness can not be used for this swap, you must use the engine harness from trucks and vans, the non-HO motors/harnesses...
SVT

To make it even clearer, you are not using the wiring from the 5.0 only the 2.9 harness with a few conector swaps and running the 5.0 computer from a non HO vehicle/

 

[magnum]

does it matter how or which wire you add on to?