okay heres something you guys have probably come across before, i have an 89 ford bronco 5.0 v8 5 speed, that has the crappy speed density set up in it, i want to convert it to mass air flow, useing mustang parts, ive read a few article refering to useing a mustang a9l computer and a 94 95 f150 harness

what i want to do is basicaly put a mustang top end on my 302 the speed density set up fires 4 injectors at once purposely wasteing fuel, the mustang set up also boosts power and torque im not gonna be able to do my diesel swap for awhile right now im trying to draw out as much economy as possible in this thing i spent a year rebuilding it im not gonna let gas prices force me out of my truck.
what i need is a step by step description of what to do, i mean to say a really dumbed down instruction manual, im not mechanicaly inept i built the damn thing but i cant seem to find someone whos done this an explained exactly what to do, also would a 95 explorer top end work? none of those came with 5 speed v8 combos so i was woried about it throwing codes and drawing back on performance and economy. please help me keep my rig!!!!

 

For starters.... Add a signature. You have been able to for the past 83 posts.
It helps when we are trying to figure out what's wrong and what you have for a truck.
So
What else does our bronco have...
You said 5 speed. But is it modded in any other way to need sefi vs sd efi.
You need to go to oldfuelinjection.com and get the wire diagram for the pinout of your ecu. Then find the pinout of an 89 mustang. Then switch pins around to match the mustang and then add injector harness from any sefi vehicle that has an independent injector harness, like a 4.6 crown vic. Then you add maf wires and a few other misc things.
It's not hard, but not easy. It's been covered many many times on here.
You won't want to try and transplant a 94 harness into your truck. Nothing works nothing plugs in. You can rearrange your current wire harness and then add what's nessisary.

Start by acquiring the mustang ecu and wire diagrams. Need a maf and maf harness and injector harness. Get a 94/95 truck airbox and maf and hoses, or retrofit an explorer airbox or get a cold air kit and maf from a mustang and make it work somehow.
Gather this stuff and come back and ask more questions.

 

There aren't a lot of wires to add for this conversion on a truck like yours, so the best route IMO is to get a donor harness from a Mustang or truck, remove the injector and MAF wiring, and then build a little overlay harness from that and insert the pins into the EEC connector on your truck. Some other pins have to moved as well to make it compatable with the mustang PCM but that can be done at the same time, if you do a search for MAF conversion on this site you should find a thread or two with a chart I posted showing exactly what pins need to be moved in the EEC connector, if you can't find it I'll post it here again.

 

SEFI vs S/D has minimal fuel savings, to the point where I doubt you'll ever make your money back in fuel savings from doing the conversion.

Batch fire does not waste fuel, some fuel is just injected against a closed intake valve on some cylinders. The engine really doesn't care. Batch fire can make for marginally worse idle quality and idle emissions, other then that it will run pretty much the same.

You only do the MAF swap when you want to put some big performance parts on there that the S/D system can't handle.

 

how do i add a signature? anyway but we have 3 fords, my truck a 95 econoline, and a 94 f150, and bothe the van and the f150 get way better milage than my truck granted my truck has 33's on it but i did the math and with the way i drive i only lost 1 mpg not to bad but i always wondered why my moms truck and the van get better mileage, when i found out about how the speed density fires the injectors well it became evident and if i can squeeze .000000001 mpg out of it im gonna do it, already got a set of electric fans to put in and im going to be deleting the a.i.r. pump cause its pretty much usless and i wanna take that little bit of drag off the engine

i know i have to change around the fireing order for the injectors as the mustang's different than the trucks i also know i have to add four wires or five depending on the harness for the maf sensor ive hear reports of roughly an extra 2 mpg with this conversion, one guy said 5 but i highly doubt that and with a 33 gallon tank 2 mpg equals an extra 66 miles i can travel, im also going to be doing headers and that mustang upper and lower intake, to help it breath a little better, and some people say that with those add ons and the speed density system the engine runs a little funky and i have connections parts will cost next to nothing, now say i can find a mustang upper and lower manifold, theres a 5.0 explorer at my local yard will that manifold and those heads work with the stang computer? i read somwhere the mariner and explorer heads are by far the most efficient

 

and im gonna start collecting the parts this week im gonna have to travel about 60 miles for the computer i just hope i can find an a9l ill get the harness out of a another bronco or f150 and ill start scopeing out heads manifolds and the like reason i wanna know about the explorer stuff is cause i know i can get it cheap

 

I'm not sure if you heard this one, but there's lots of incorrect things out there on the internet, worse yet, often stated as substantiated fact.

Converting from SD to MAF solely to get an "upgrade" from EFI to SEFI is a whole lot of effort for no real gain. Feel free to do it - at least you'll be able to use a generic OBD2 code reader when you're done.

 

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You don't need an a9l. You can get any maf mustang ecu. The a9l and a9p are the best stock ecu and has a few minor differences then the others. An auto ecu will pull timing more than the manual ones during shifts. As far as codes due to not using an auto trans, there will be none cause its a mechanical overdrive trans and not electronic in the 89-93 mustangs.

You'll need
ecu
maf harness
injector harness from anything sefi (8 injector wires to put into your stock ecu plug)
airbox from a maf truck with hoses to tb

That's really all you'll need I think.

The mustang intake sucks. Don't use it
Explorer intake is better than mustang but the stock truck intake is somewhat better. Explorer intake may give you a little better low end velocity but that's it. Use your stock truck intake.
Explorer heads are usually gt40p heads and have straight sparkplug angle which hits on stock manifolds. Find early 95 heads and they will work.

 

I'll have to copy what I got from IST on what wires to change out, won't be till Thursday tho.

 

The OP is looking for a Mustang A9L PCM for this swap, it's OBD-I.

 

Honestly, I'd say you'd be lucky to pick up 1 solid MPG, let alone 2 or 5.

Your truck gets worse mileage because you have 33" tires, not because its speed-density. The tires lift the truck nearly 2" over stock which itself causes a lot of extra drag, and the tires are much heavier which require a lot of extra power to get spinning. Additionally the tires have more rubber hitting the ground, which creates even more friction.

 

Ah, okay. I guess I was sorta ignoring that part and assumed he would just source stuff from a '95+ truck. I'd think that would be the best bet for fitment and such.

But again, I question the rationale for the whole project. Lots of effort for little to no gain.

 

No you're losing more than that because tires that much bigger than stock create several compounding issues that together make fuel milage look a lot worse than it actually is. The First thing you need to do is recalibrate your speedo so the odometer is accurate since that is what's used to calculate fuel milage. The speedo is cable driven on your truck and recalibrating it involves changing the little plastic drive gear on the transmission end of the cable, but to know which new gear you need you need to know what gear the truck now has, there's just 1 bolt retaining the cable in the trans or Xfer case so it's pretty easy to look. Once you have that you pick a gear with fewer teeth to speed up the drive cable which is what's needed when fitting larger tires since they make the speedo read low and the odometer count fewer miles. http://www.transmissioncenter.org/Fo...eter_Gears.htm





On the early trucks like your it is, but this complicates the install slightly because to make the mustang computer work correctly with the old firing order you have to rearrange the injector plugs and delete one of the O2 sensors, otherwise it'll never run right. A better solution would be to simply change the cam in your motor to one with the HO firing order, the stock cam is brutally small and is the major reason that vintage 5.0 truck motor produces such little power. You could get a lot more power and take advantage of the greater adaptability of the SEFI MAF system with a cam swap, and you wouldn't have to hack the wiring and compromise the EFI setup just to make it work.

Forget about the Mustang intake it flows a LOT less than the truck version. The Explorer version is better but it's still not as good as the stock truck intake, to get the necessary hood clearance in the Explorer the lower intake portion was shortened vertically and that resulted in sharp kinks in the lower intake runners which hurt airflow.

 

Wouldn't it be easier to just swap in the Explorer 5.0?

 

it might be easier to swap in the explorer motor, ill talk to the guy and see if he'll give me a deal, if its to much though itll be easier to do the harness and such i just think the reason that ones in the scrap yard is because of the engine i dont recall any serious body damage ill give it a once over

so if this engine is a runner, what about my tranny? wont the ecu pull codes cause its bein hooked to a 5 speed? cause i was thinking about that if that engine is a runner and its mileage lower than mine (125,000 roughly) its possible id go for it