I have a 1991 Ford f150 with a 5.0 and an automatic it had headers/exhaust, an rv cam and had been bored .030 over. A sheet metal skrew thru the piston caused another rebuild and I added a few more performance mods. It now has Ford racing aluminum heads, a gt40 explorer intake and a 75mm summit racing throttle body and I got rid of all the emissions stuff.
Now from what I'm finding I need convert it to a MAF system to get it to run right. I never wanted to tear into the computer/wiring/spaghetti system nightmare, and honestly have no idea what a MAF Conversion even consists of.
This forum has proved helpful thus far in the build, but being as lost as I am now Im not sure I can peice together the information I need by reading all the forums that loosely relate and thought I should try to get advice for my particular application.
Any info on what I need to do it and how to do it would be greatly appreciated. My budget forces me to do this myself and on the cheap.

 

Check out this thread about the MAF conversion:

https://www.ford-trucks.com/forums/1...96-f-150s.html

How did you get a sheet metal screw to meet a piston?

 

Thats something I'd love to ask the guy that did the last rebuild.
I looked thru that thread and did some other searching. The Ford kit that runnrite now sells is $850 which is kinda out of range for me. I found a magazine article that talked about a partial layover harness you can buy and then source your own ecu, MAF sesor, ect.
Does anyone know about this partial kit or where to find it? And what all sensors and computers will i need and out of what?

PS. I don't know what happened with my other profile but I couldn't get back in. I'm Ian with the 91 f150

 

You can also try to find a harness and ECU from a junker at your local salvage yard. Grab as many of the sensors along with the harness, including the MAF sensor itself. That should be a lot cheaper than those conversion kits. It's easier if you can convert a car that's similar to the donor. You just need to spice in the MAF sensor and replace the ECU. Check a Haynes or Chilton's manual to look up the wiring differences between the SD vs MAF versions of the same car, and make the appropriate changes. That's how I did my Mustang; there were no conversion kits for purchase back in the olden days. The new kits offer the convenience of all the parts you need with full instructions. But they're not strictly needed if you figure out what needs to be done.

 

Ok so with a 96 explorer intake and a mustang throttle body and I believe AOD trans (I think. no computer controlled overdrive correct?) What donors should I be looking for? The trucks new enough to have MAF would be the E4OD right, so then would a manual trans MAF truck work or should I be looking for older an automatic mustang, 87-9? had the AOD right? Or what, if any, explorers would work?
And how much of this will plug in, or what will I have to splice in?

 

I just had a local Ford dealer search the vin and he said the truck had an E4OD. I don't have a button for the overdrive select tho, I thought no computer overdrive ment it was the older AOD?? Any help on how to identify which it is for sure?

 

OK, the one thing you will need to plan for is your auto trans. When you identify a new ECU to use, you will need one that can control an electronic trans (assuming you have the E4OD). There are some but not many ECUs you can use for this. There will be MANY more ECUs for a manual trans that you can program.

An alternative is a third party trans controller (Google: US Shift)

Aside from the trans...what you will need is a new ECU, a new injector harness, a MASS Air wiring harness, a MASS Air Senor and a housing for the sensor.

It doesn't sound like you are going too high on your target horsepower but if you plan to make more than 500 hp to the back of the motor, let me know.

You can get an entire new harness from a donor truck but that might be a lot of work (I go through each wire and make sure they will work). But I don't know what truck you would get that from. I have built mine myself.

What you need to decide now is what to do about the trans...are you going to get a third party controller or are you going to find a tunable ECU you can use? If you want an ECU to still control your trans, you will need to find an ECU that you are able to tune...you will find several ECUs out there that control an auto trans but not all are tunable.

Once you decide on that, the rest will be easy

 

Thank you for the info! I have the AOD automatic transmission, that means its not computer controlled and I can use an ECU from a manual or another AOD donor and don't need a stand alone trans controller, correct?

 

It looks that way. If your trans doesn't need any input from the ECU, then you are OK. I know the AODE is electrically controlled but since you have the AOD you should be OK.

Assuming we are correct about the trans...you can really get any tunable ECU out there. An ECU has a long part number, like F2TZ-blahblah.... But ECUs also have a 3 or 4 letter strategy, also called a catch code. This is what you need to pay attention to for tuning.

My suggestion would be either the A9L ECU or a U4P0. Either would be sufficient for what you are doing, fully tunable. I think the A9L is a bit more supported. There are also others you can use as well.

So next is to decide what software you will use to tune. Go to the website for eec analyzer and look to see if they support the A9L and U4P0 (I know the A9L is supported). Then go to tunerpro's webiste and see if they support the same (I know they do but this is part of the research you should do). I use tunerpro.

Next, you will want to get a quarterhorse tuner to go on the back of the ECU. Don't get a tweecer. Yes you can tune with it, yes it can data log and has a nice rotary switch but it is the biggest POS there is for tuning.

Then you will need hardware. You will need a MASS Air flow sensor. Let me know how you are going to proceed with this and I can direct you. If you want to make your own housing (https://i.imgur.com/Ok0SscK.jpg) that is one thing but if you use a stock housing that is something different. My suggestion would be to get a stock housing for an 89 mustang 5.0 and use the MASS Air sensor that comes out of those.

Tell me which way you are going to go with these things and what questions you have.

 

Thanks for all the info!

So I think I'm going to go with the A9L, it seems to be pretty ready available and supported. However I know some mustang 302s have a different firing order. Is that what the quarter horse tuner is for? Tunerpro and eec analyzer are software I need to program the quarter horse tuner? Sorry im very unfamiliar with computers. I'll probably take a mustang housing and MAF and adapt it how I need. I already have the gt40 intake so I'm thinking that won't be too bad. And can I get the harness from a mustang with that ECU?

 

That A9L computer is for the HO 302 engine, so it will have the same firing order as the 351W. I don't think any tuners change that. Just make sure you get the proper wiring harness and connect the injectors in the proper order. Of course, make sure you wire up your spark plugs the same way.

 

I have a 302 truck motor. Not the HO or 351

 

The TYPICAL way to manage firing order is to move/install pins on the 60-pin ECU connector in the correct places (meaning proper firing order for that ECU). However, yes, a tuning device like the quarterhorse can change the firing order for a supported/tunable ECU.

I think you made a good choice, the A9L is widely supported. The one downside is there are very in demand and, as a result, can be expensive. So one of the things I like about these is, with moving only 4 pins and editing the firing order in the tune, you can change over to a U4P0 ECU, a little cheaper and can be easily obtained. You would need to change the tune as well.

Yes, you use tunerpro (free) to write a new tune to the ECU. The software eec analyzer or binary editor does the same thing but are at a cost. Since I don't use that software I am not as familiar. I heard it does OK.

As for the wiring harness. if you find one that matches the ECU, that would be good, but it is not needed. You can change your existing harness with the addition of an 8-connector harness for the injectors and a 4 pin connector for the MASS Air sensor. When I say 'change your harness', I mean you can re-pin the 60-pin connector for your new ECU, saves a lot of $$.

Once everything is installed you will need to get it tuned. The BEST way is on a dyno, if someone knows how to tune with this ECU. There are MANY ways to make a motor run and achieve a good target AFR but it needs to be done properly for the ECU to not try to overcompensate in certain areas if done wrong. There are ways to tune yourself, but you must learn and have the proper equipment, or you can find people to do it for you on-line by providing logs. A few options. Just something to plan for in the future. Also, it is helpful but not needed, to install a wideband O2 sensor. This will help for tuning, but again, is optional.

 

Ok so I have most of the parts needed now. An a9l, MAF, and injector harness out of an 88 mustang. I also have the moates quarterhorse tuner and I downloaded tunerpro rt. I guess i still need the harness for the MAF, but im not sure if im looking for another harness or just a connector that i have to splice in. If it is something i splice in how do I do that? Since the connector for the plug is not on the injector harness is it still nessisary to swap the injector harness?
Since the a9l is for a 5.0 ho i need to switch the pins for injectors 3 and 5 and 7 and 4 on the harness side, is that correct?

 

You have a bunch of pins to move and add so here is a list to use as a reference. The mustang harness you have is laid out for a passenger side PCM location which is opposite what a truck has, so you'll be dismantling that to remove the injector portion and then when you source a MAF sub harness add both of those to your existing truck harness. Wires at pin locations in color have to be moved, wires at pin locations in grey are to be added.