MAF vs. Speed density?

[msweb]

I think I found a donor, a 89 Towncar, 5.0, 120,000 miles that I can get cheap. I'm afraid it's a Speed Density car though (haven't seen it yet so don't know).

If I choose to go with Speed Density, other than performance modifications, what are the drawbacks? What does the Speed Density sensor pick up off of? If I decide to buy it and later want to convert to MAF, what all needs to be swapped? Intake, sensers, MAF sensor, harness, computer?

Will the AOD from the Lincoln work or do I need to make a lot of mods? I'm just trying to make the simplist swap I can and looking for reliability, not mega horsepower.

 

[Socal Tom]

Nothing is wrong with Speed density. It doesn't adapt to modifications as well as MAF, but it works great. It has fewer sensors, which also means less things to break.
To convert to MAF later, it takes and adapter harness $50ish, a Mass Air Sensor and a MAF computer. Its about a 2 hour job. I carry a Speed density computer as my back up. I unplug the MAF, hook on the SD computer and hook a vacuum line to the BAP sensor, and I'm good to go.
Tom

 

[kjbronco]

AOD would work, with 120K miles should be rebuilt and there are a few key upgrades that should be addressed when rebuilding, such as OD servo and band, lots of good info on web and this site. Also will need AOD/D20 Adaptor installed at $500 or so (if you do the work or have it installed when trans is rebuilt) so not really cheap, but you would pick up a good overdrive. I seem to recall 1989 could be either the later model AOD with the better tailshaft oiling -or- the earlier, need to know before ordering AOD/D20 adaptor or be prepared to modify earlier AOD to accept later tailshaft. All things being equal I'd rather have the MAF but for a mild built unit the speed density is pretty good.

 

[turbokid]

this is exactly what im doing. just pulled the motor and trans from a 90 lincoln
yesterday. im pretty sure all the towncars are speed density.
let me know which harness you end up using.
good luck!

 

[msweb]

this is exactly what im doing. just pulled the motor and trans from a 90 lincoln
yesterday. im pretty sure all the towncars are speed density.
let me know which harness you end up using.
good luck!

We looked at the lincoln today and and weren't real impressed with it. Mileage was higher than stated and the guy selling wasn't the best salesman, telling us to go ahead and do some burnouts, he did... Oil was burnt and it didn't want to idle even stalling a couple of times.

We're in a bit of a time crunch so now I'm back to the Explorer engine but maybe just putting a 2 barrel on it tillI can afford all the parts needed to switch to EFI.......

 

[bronx]

You can always run an aftermarket computer on a Speed Density engine.
I'm running this:

http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_ford_mustang_5_0.htm

I bought the computer, wiring harness, and wideband o2 sensor for about $500.
The wideband isn't necessary, but it allows for better tuning.

 

[msweb]

?:?

Ok, here's where we're at.... I bought a 90 F150 and will be using the engine (Speed Density) from it but due to hood clearance will need to switch to an 89 5.0 HO intake that came off of a Cougar.

If I keep the Speed Density and do not use the MAF, will the intake swap conflict with the Speed Density?

 

[Socal Tom]

The intake won't matter you can still run the speed density. The MAF meter is actually a seperate component. Even if the MAF meter were in the intake it doesn't have to be used. I use a SD computer as my backup. I just unplug the MAF, put in the new ECU and then hook up a vacuum line to my BAP sensor and it becomes a MAP ( manifold pressure) sensor. My air filter is hooked to the MAF so it stays where it is.

If you want to use the MAF computer, then this where I got my adapter harness http://www.mass-air.com/Products.htm The instructions are simple, and its not hard to move the pins if you follow the instructions.

Fordfuelinjection.com shows how to move the pins here http://www.fordfuelinjection.com/?p=74

 

[YellowBronc]

We're in a bit of a time crunch so now I'm back to the Explorer engine but maybe just putting a 2 barrel on it tillI can afford all the parts needed to switch to EFI.......

You trying to get EFI on before OCBR Mike?

 

[msweb]

You trying to get EFI on before OCBR Mike?

That's the goal. Anthony dove in head first today and we're tearing down the F150 top end at the moment. We're going to try and swap to the T-bird/Cougar intake tomorrow and see where we are. I've decided to stick with Speed Density so hopefully, it'll be a little easier...

Assuming she's running by then and I decide my good old Blue is up to the job of towing her out there, I'll be fortunate enough to meet you and all the others! ;D