So I have been repairing my car for about a year now and I finally got it running about a month ago. The problem is it stays at 14.8 afr even at wot. It is also throwing a code for iat circuit voltage high, so I ohmed the sensor and it checked good, but as I was messing with the harness I noticed it had a gm iat sensor harnes spliced into the 5&6 pins on the connector. So my question is does the scaling on the maf get changed in the ecu for sd so that if someone just went back to using the stock maf it wouldn't work correctly?

 

Make sure the SD Option for IAT Input is set correctly in your rom. Does logging with evoscan show the IAT reporting correct temps?

 

That's the problem I don't have a cable n so can't use evoscan or the ecuflash otherwise I would jus compare mine to a stock map. I'm just wondering if its sound logic or if the scaling wouldnt change and I should jus buy a new maf

 

How are you running it? Did someone flash a SD map for you or did you just hook up the iat and fire it up?

 

I bought the car in a stock format with a maf and haven't had a chance to tune it had to have a new engine built and transfer case rebuilt and there's no tuners in ak and haven't had the money to get it done. O and I forgot to mention that I was able to hook my obd2 scanner up to the car and that's reading that the iat is at -40 and it's about 80 up here and the s fuel trim is bouncing between about 7.3 and 10.1 can't c the bottom half of the screen cuz my buddy broke it so I couldn't tell u wut the long fuel trim is. But it had the gm iat harness tapped into the wiring so I'm thinking maybe it was flashes for sd and scaled for the gm iat so now that it is monitoring off the maf it's getting the correct voltage that voltage is just a different temp for the gm iat than it is for the Mitsubishi maf. Is that correct or am I just over thinking this and it's a bad maf with good ohm readings

 

are the connections to the maf air temp sensor in place and the gm iat is still connected also ???

 

Yup the jus soldered the harness into the wires as opposed to using a set up that jus plugs in like the spoolinup one

 

So.....have you even flashed an SD rom to it, or is it still running on the stock rom and you just hooked the SD stuff to it?

 

so its using both temp sensors ??? if you have the maf plugged in disconnect the plug from the gm iat

 

No I haven't touched the car I bought it the way it is. Then 11 days after I bought it the oil pump pulley snapped in half so I had to have a new engine and transfer case built. But as I'm working on the car I'm finding signs that the previous owner had a high hp engine in it before such as a 5 speed in an mr, a double pumper setup and the gm iat harness hooked up to the maf wires. So that leads me to believe he may have had it tuned for sd and then the shop that put the junkyard swap in put a stock setup with a maf but didn't retune the engine for the maf again. So like I said I haven't touched it to put on sd myself and can't confirm it cuz I don't have a cable for ecuflash or evoscan but I think it was tuned for sd to used with the previous engine before it was stolen and then the dealership I bought it from had a stock setup put in before they sold it to me

 

The gm iat sensor isn't there just the harness tapped in I just read that when swapping to sd with a gm iat u have to rescale the readings for what the gm iat uses

 

It could have had an AEM in it too, that would account for the IAT. It sounds like you need to get the cable and such and start over. I suspect it's a stock ecu setup and you're trying to run it sans maf.

 

Yeah I would love to but a little tight on money right now so I'm gonna get the cable as soon as I can but if its just a bad maf sensor then I'd like to get that before the cable.

 

So I was just wondering if it was possible that when you tune for sd that you change the scaling for the iat since its from a different manufacturer because I still don't know a whole lot about tuning and the ecu. Sorry little scatterbrained at times so I forget to finish my thoughts.

 

It's a totally different Rom not just map scaling. If you don't have a cable and know what you are doing you will be buying another motor by weeks end. Get a cable and at least get a remote tune. I know you say money is tight, but your going to kill your new motor no joke. Just leave it alone till you have the money, its not worth it.