fuel cut/ power loss.

[fuzzynuts]

searched and couldnt find anything on here about it, but heres my problem. i have a 90 legacy 5speed manual with a 91 engine in it.. completely stock. non turbo. evap canister was eliminated, not sure why.. but. you start the car. it starts right up idles amazing. once its warmed up it looses half its power at 2300 rpms.. but.. if i unplug the maf, it runs perfect when the cars warm. with it unplugged it wont idle on its own when its cold. any ideas? i plugged the maf in again and cleared all the codes and took it for a ride. these are the codes that came up
14,15,16,17,22,23,24,31,32,35,49. i havnt checked the codes with the maf unplugged yet. im sure some of those are set off by the car getting put into limp mode.. please help.

[cj91legss]

holy shit, are there any codes you haven't gotten yet..........

Anyways with that many codes, that's rediculous. I would try and look at your engine harness and see if the plugs are corroded or show any signs of weakness... that many codes, seems like there's more of a simple problem.\

at one point i had 6-7 codes throwing and found that one of my engine harness plugs had a little too much oil & dirt in it.

also might wanna check some of the chassis plugs under the dash as well, just look for signs of corrosion.

[fuzzynuts]

ok ill check those plugs, but i dont understand once its warm, if i just unplug the maf it runs perfect... no fuel cut or anything

[vrg3]

This may be a dumb question, but are you using the correct MAF sensor? If you're using the sensor that used to be on the 91, and the 91 was an automatic, you're using the wrong sensor.

Your 1990 5-speed's ECU needs the aluminum-body MAF sensor from a 90-91 non-turbo manual or from any 91-94 turbo. It's made by Hitachi and is part number 22680AA170.

[fuzzynuts]

no, good question haha i didnt know there were a bunch of maf's for the car, but i did check and its the correct one.. aluminum body hitachi with part #22680aa170.... any other ideas? maybe is there a way to put the maf on a toggle switch haha?

[vrg3]

It's normal for the engine to run without a MAF when warm but not when cold. The n-alpha fuel calculations are too far off to properly run the engine cold but close enough when it's warm.

When you have the MAF sensor plugged in, does the Check Engine light illuminate?

Have you tried a D-check?

The problem could still just be a bad MAF sensor. Do you have another you can try? Or if not, have you tried cleaning the one you have?

[fuzzynuts]

whats a d check? and yep tried cleaning this one baught one from the junk yard slapped it on there and its the same, tried a two more that a friend has and still the same..

[vrg3]

D-Check is an active diagnostic mode. Check the sticky compilation thread -- follow the links about engine codes.

When you have the MAF sensor plugged in, does the Check Engine light illuminate?