943kgt

iTrader: (1)

ok i need a mass air flow sensor for a 89-95 22re 4wd manual with california emissions.. let me know what u've got!

chimmike

why did you post in 2 different sections, both of them being incorrect?

943kgt

iTrader: (1)

sorry about that one, if the mods could please delete one. where is it supposed to be posted if not engine/trans/parts?

rdharper

Why would you need a MAF in a 2nd generation truck?

943kgt

iTrader: (1)

truck starts and runs for 2 seconds then shuts off
https://www.yotatech.com/forums/f116/doesnt-stay-running-106154/

rdharper

No MAF in 2nd generation stock. VAFM, totally different method, same function. Failure mechanism is totally different between the two.

The usual failure for a VAFM is the phenolic internal to the RTVed-in angular position sensor.

Also, the VAFM is very expensive from the dealer, over $700. But near as I can tell, they all eventually wear out, much like an old fashioned needle and record will eventually wear out. You can buy them for less if you look around, but keep in mind that in this instance, a new part is a better bet depending on how long you expect to keep the truck. My guess (and it is a guess based on a small sample) is that they wear out somewhere around 200K miles.

If resistance does not swing evenally with flapper movement, if there are spikes or a wrong value at a static position (such as closed), then it will need to be replaced. Or you can open it up and inspect it if you are sure it is bad.

943kgt

iTrader: (1)

127k miles, i work for a chain of dealerships that has toyota as one of their franchises, so i get 10% over cost we'll c tommrow what a new one costs, because as far as i can tell everything points toward that sensor its pretty haggard looking.

rdharper

I'm thinking the symptom may disappear if you pull the connector to the AFM. A CEL will come on, which won't hurt anything, but if the symptom disappears, that is a clincher that the VAFM is the problem.

When I had the problem on my '85, I spent quite a bit of time verifying that it was bad, given the price. Eventually I opened it. Visual inspection made it obvious what the problem was. Tried to fix it, but couldn't.

Replaced it... fixed it. I did not try disconnecting and running it. But apparently several sensors work this way, ie: disconnect, throws a code saying the part is not working, but the ECU bypasses it and symptom disappears.

TPS works that way for sure, and I think it will be so for the VAFM. You could drive it that way until you get the part. Won't hurt anything.

943kgt

iTrader: (1)

yea i was just gonna bypass it with the diagnostic box jumped but ill c what happens when i disconnect the connector thanks for the input, i was pretty stumped on this one for a while but thought it out

rdharper

I would like to hear if it works as expected.

Also, did you build the diagnostic box, or buy it, or what? Sounds like a useful tool.

943kgt

iTrader: (1)

truck wouldnt start at all with that connector off. i took the vafm off and shook it and could hear something rattling around inside lmao so i think thats the problem. Brand new my price is $430 bux so i ordered a used one for 45 bux. the diagnostic box is stock on all 89-95's its right near the fuse block in the engine bay, definetly does the trick!

rdharper

Thanks for the info.... and it makes sense to try a used one for that price as a sanity check. If and when it goes bad, you can buy a new one. $430 is a steal compared to normal dealer price.

I did the same thing for the TPS probem I had, bought a used one and even got the guy to provide 3" of wiring so I could use the setup to make easier connection for testing. Think I got it for $15 plus 5 for shipping. The piggytail alone was worth that much to me. I also used it to understand how it worked.