help with troubleshooting MAF

[goode]

kamusta sa mga nagtitipid na motorists na tulad ko!!! hehehe!

I think I have a problem with my engine's MAF. It's a 4G63 from the '90s Galant GTI. After a top overhaul last year, driving was practically smooth until 2 months ago when my engine started dying when idling, especially with the aircon on. I temporarily remedied this by raising the idle speed by loosening the adjusting screw on the throttle body. even then the idling was very erratic. it would go up and down like anything and if the compressor happens to engage while the idle speed is on its way down, my engine dies.

Yesterday was the worst that happened. I had a hard time starting up, and then when I started to back out of my garage, my engine died while accelerating. I started again, but it took a while before I finally got out of my garage. I then tried to still proceed to go to work until I reached my first uphill run (I live in antipolo) where the engine almost died, pero naagapan ko agad nung nag clutch at brakes ako agad. But no matter how hard I tried to try to go uphill, my engine almost always died. Kaya gumulong na lang ako backward and barely made it home.

I checked the plugs, they were good. I checked the air filter, but it was still kinda clean, I just washed and oiled it 3 weeks ago. Basta walang load nakaka rev naman makina, but only up to around 3000rpm. Anything higher than that, biglang bagsak. Out of curiosity, dinisconnect ko muna ang MAF plug, that's when the engine idled smoothly. Nakamaneho pa ako around the block and to my office and back home, medyo mahirap lang mag start galing sa matagal na patay.

When I plugged the MAF again, ayaw nanaman. It looks like there's something wrong, but, nalilinisan pa ba yun? paano? How much is a surplus unit from banawe these days?

Salamat sa maski anong mga suggestion na maibigay ninyo!

[samurai_rex]

1. might be the servo kit
2. might be the cam angle sensor

but it might probably be no. 1

[Conan®]

You can spray the MAF with carb cleaner but be careful with it since it's very delicate. Don't ever drop it or let anything solid come in contact with the wires.

[samurai_rex]

just to add to my post,

have the mitsu casa use MUT (Module Under Test) on your engine to diagnose the problem.

does not matter if your 4g63 is installed on a non-mitsu chassis. 

[goode]

You can spray the MAF with carb cleaner but be careful with it since it's very delicate. Don't ever drop it or let anything solid come in contact with the wires.

Hi!! Thanks sa input!!

I sorta nicked one of the honeycomb looking channels while enthusiastically spritzing both air channels with a can of carb cleaner I bought. I didn't realize the MAF sensor was huge! I've seen the one from a ford lynx, but this mitsubishi unit seems to be a more precise instrument! ang haytek ng itsura!

I decided to man-handle the maf sensor, rather than just try spritzing the carb cleaner while mounted, wala kasi nakalagay sa instructions ng carb cleaner na ok lang siya sa sa fuel injected engines e. so, after using up more than half the can binilad ko na lang sa araw para mag-evaporate yung carb cleaner fluid. after that,  one-click lang ang start uli and idling was stable!!!

Thanks Conan!!!

[goode]

just to add to my post,

have the mitsu casa use MUT (Module Under Test) on your engine to diagnose the problem.

does not matter if your 4g63 is installed on a non-mitsu chassis. 

Hi po! Thanks din sa input mo, but it looks like my maf sensor badly needed cleaning lang, although, siguro dapat ko na rin i-sked na palinis ang TB, malamang puno na din ng dumi.

But what kind of info will this test give me? And I can go to any mitsu service center for this? And they'll "admit" my car for testing?

[speedyfix]

the test will tell you if the voltage the maf is sending the computer is correct.