Maf Conversion help

[rangerchase]

I am currently rebuilding my 2.9l. I will be running a cam, ported pollished heads and intake, 2.8l pistons and 19lb injectors. Do I need to do the maf conversion to prevent it from leaning out, or is there some other modification I can do to allow it to run properly? The maf conversion seems pretty expensive, IST lists a basic kit for $1300, albeit I would most likely only buy the specific parts brand new, and go to the wrecker for most things. Any help that people could give me would be greatly appreciated. Thanks

 

[AKBroncoII]

leaning out with 19lb injectors? You will be running rich not lean. I bet even if you do swap to a maf setup it will still run rich.

 

[rangerchase]

wouldnt the truck be running lean after all that work? ive heard the speed density sensor doesnt correctly measure airflow, so if Im adding a ported top end and a cam it would be taking in alot more air without being able to properly modify the a/f ratio.

 

[AKBroncoII]

I will almost guarantee it will be running rich. I'd stick with the factory injectors as it can better tune the factory injectors anyways. Try it first, I doubt you will be running lean though.

 

[rangerchase]

Sounds weird, but Ill try it. Thanks

 

[Psychopete]

Who really knows? The computer is going to be really confused with all of those modifications.

You will need to do something about the computer if you're running a really aggressive cam. What would be really cool is if you went with a carb setup and found a way to adapt the 2.8L Duraspark crap on it (this is what I would try to do if I did it all over again IMO). That or an aftermarket computer, but I like cheap and easy solutions.

I ran a '90 MAF computer with an IST Air Adjuster. I recall that adjuster being kind of hard to find, I eventually found one on Ebay that some guy was selling. I ran a cam, stock 2.9L pistons, milled heads .030", headers, etc. The engine did not run right on the MAF setup alone with 19lbs injectors.

FWIW, This was 5 years ago, my 2.9L came out last Sunday to be replaced by a 5.0L V8.

I don't know if I want to sell the computer yet (just in case I need to go back), but will be for sale at some point. It's an auto computer. The IST Air Adjuster, I am keeping for a future project.

Pete

 

[fastpakr]

I know it may not be what you're looking for, but a 4.0 swap will give you everything you'd get from those mods for a fraction of the price. You'd also get to keep the factory reliability.

 

[rangerchase]

psychopete, did you ever get the 2.9l running properly before you swapped it out for a 5.0l? How did it run with the conversion, and how did it run before the conversion?

 

[Psychopete]

psychopete, did you ever get the 2.9l running properly before you swapped it out for a 5.0l? How did it run with the conversion, and how did it run before the conversion?

Yes, I drove it for the past 5 years with the conversion. For what it was, it worked pretty good.

The engine cracked a head about 6 years ago, I rebuilt with the extras and did the swap all in one shot. I have no clue on what would have happened if I ran the stock computer, but everyone told me it wouldn't work well, including the guy who ground my cam.

Just don't expect V8 power from that thing once said and done . FWIW, the only thing I regret doing is not upgrading the valve springs with the larger cam.

Pete

 

[rangerchase]

Haha yeah I know its not a v8. Is the wiring all that complicated for the MAF switch? I know you need a 1990 3.8l or 5.0l maf, and a 1990 eec-IV computer. Did you go to IST for the jumper harness, or is it a common harness I can get from a jobber?

 

[Psychopete]

Haha yeah I know its not a v8. Is the wiring all that complicated for the MAF switch? I know you need a 1990 3.8l or 5.0l maf, and a 1990 eec-IV computer. Did you go to IST for the jumper harness, or is it a common harness I can get from a jobber?

I think I would have better off with a 2.9L MAS, but I did use the 3.8L MAS.

For 86-87 the wiring is a little more difficult. 88+ is extremely simple. Luckily, I believe most of the work on the pin-outs is done for you in the tech library for your '87. I spent about 3-4 hours hashing out every single pin for both computers.

For the MAS wiring, I pulled the plug from a '93 T-Bird 5.0L wiring harness. The wiring colors were actually right ironically.

The IST Adjuster is actually a little box that runs between the MAS sensor and the computer. It has a little screw to make adjustments and a little digital indicator to show you how how much it's adjusting. Here is the manufacturer's web site: http://www.mass-air.com/ Top right pic in the header is the device. FWIW, I paid $100 for one that some guy had on Ebay that he never used.

FWIW, My computer and MAF wiring will be going on Ebay or in the classifieds soon. Let me know if you'd be intereste and we'll work something out. I have some other stuff you might be interested in as well.

Pete

 

[rangerchase]

Mines an 87 so Im not sure if it will work. Wiring isnt one of my strong points. But I am definately interested in the components for the swap. What else are you getting rid of?