dfarr67

Dave- what type of input is the Toyota ECM expecting from the MAF? Digital or analog, and in what range?





I'd like some help to answer these specific questions.

Also looking for advice on choice of a suitable MAF- something that is common in the wrecking yards that would work well and preferably have a AIT built in- bonus if it matched my intake tube of 3in dia.

InternetRoadkill

AFM and MAF are two very different animals. The AFM (VAFM) puts out a voltage of 0 to 5v. It also has a separate air temp probe and a switch for turning on the fuel pump when it detects air moving thru it.

dfarr67

This is good info- I was aware of it generally but not the actual values. I know you built a translator for the 3.0L and I'm working on sourcing one for the 22re these are questions being asked of me. I have a maf out of a 3100 with separate iat- not sure how the fuel pump can be bypassed for safety.

shaeff

Check out the MAFT. Should be able to get it to work w/ the 22re's system, as it's very similar to the MKIII Supra's N/A AFM. The MAFT allows you to swap to a GM hotwire sensor. If that's all you want to do, you just need the basic MAFT, not the pro or gen2.

http://www.maftpro.com/

and the forum:
www.fullthrottletech.com

dfarr67

From MAFT forum: The 22RE doesn't get any support....

I would like to put a 3in gm maf on my 1993 toyota pu. i have a translator for a supra. would this work on the 22r engine since they both use the same flapper type mafs?


the regular translator is not compatible with any of the flapper-door MAF's, only the Karman Vortex style like on a 7M-GTE

You could use a Gen-2 or a Pro though as long as the flapper is similar to the 7M-GE unit

dfarr67

I was looking at these awhile back and also Split Second- was more interested in a specific translator instead of trying to program my own. The gen 2 price is right though.

InternetRoadkill

To answer a question I get from time to time: Building a proper VAFM to MAF translator is not cost effective. I built the experimental one using parts I had laying around. But it's not built well enough to take the abuse of an engine compartment for any length of time.

dfarr67

So...why did you do the experiment in the first place? Would you call it a success?

I can pretty much get free GM mafs locally- I think in the long run the Toyota afm's will be harder to get used and where I live you might have to wait a week to source one. And in my case the Supra afm is huge, the maf is far smaller. Feeling the resistance of the flapper, I don't buy the arguement that there is no gain to be had either power or fuel efficiency, the maf's are so common as well.

InternetRoadkill

The experiment was done for a couple of reasons. First, I wanted to know if the VAFM is hurting the performance of the engine. (Yes, it does.) Second, they said it couldn't be done. I thought otherwise. (Yes, it can be done and it makes a big difference.)

The problem with producing the translators is that the tooling costs are too high to justify one or two units being made.

dfarr67

What are your future plans for this? If none, would you consider making this available for the DIY'r ?

InternetRoadkill

Don't know what I'm going to do with it. You need a microscope and special tools to assemble and program it.

dfarr67

How does it come up short in the engine compartment environment- is there heat sinks? A conformal coat won't help? sealed housing? Or is it just an experimental bare board?

InternetRoadkill

You have to use components rated for industrial temperature ranges if you expect this to survive under-hood conditions. There's also the issue of weatherproofing and corrosion proofing.

dfarr67

Well it looks like the Split Second PSC1-004($322) or the MAF Translator Gen II($260) both have IAT feeds, but I'm wondering about the fuel pump switch. Has anybody had experiance with these, price is right fot the second example.

dfarr67

Can anybody confirm these 22re VAFM measurements? I'm looking for the actual voltage range, I thought I was looking for 0-5, or 5-0V or somewhat close. The reading I come up with is 2.8-7.3V taken off the yellow/blue wire with a full sweep of the vane.

InternetRoadkill

I had to pull my old notes again. It looks like 0-5V is incorrect. I must have confused it with another system.

Note that the output voltage of the VAFM is dependent on the battery voltage. For mine, with a voltage of 13.7V running thru the vehicle, the VAFM puts out 3.03V (idle) to 8.72V at wide open. Your mileage may vary.

The resistance of the temperature probe @ 72F is 2.27K.

dfarr67

Good at least I'm in the ballpark- I just plugged in a spare afm that I could easliy manipulate and tested with key-on, batt was 12.2V. This was to confirm a conversation with Split Second on a model PSC1-009 that is 0-9V he also suggested using any Nissan/Toyota/Ford maf sensor as these work on a 0-5V whereas the GM units are alone using frequency- too bad, my packaging really favors my 3in GM maf. Apparantly the 009 looks after the fuel pump relay and can read iat as well. Adding the costs up....getting expensive.

Abaco= $370- smallest available in 3.5in
VMP tuning- maf housing $99 + 2005 Ford maf $50 + piggyback $322

Gives one a pause, but as good as the truck runs with the Supra vafm I think it has a few issues that need 'tuning' out. Almost at the point of making an adapter harness and put a tuneable ecm in and run map (or my GM maf).

gearhead350

can you give a digram of how to make it with no regard to price

CamTom12

Back from the dead!!

Just curious on the outcome of your experiment!

JamesD

Probably the cheapest and easiest way would to ditch the the 22RE intake manifold and go with a carb manifold with a GM 4cyl TBI FI. Parts are plentiful and cheap.

James