86 240 DL MAFS failure (2nd in a month) Topic is solved

silveriodine · Post by **silveriodine** » 15 Dec 2003, 14:15

I just replaced my MAFS on my 86 240, and 3 weeks later, i was backing out of a parking space and hit the throttle and POP!, car dies. I unplugged the MAFS from the computer and it idles, just in "hobble home" mode. Could it have been a faulty MAFS? or, is there another part that could lead to premature failure of the MAFS. I only logged about 300 miles before the dang thing failed again. Also, I just installed a nice new preheater hose, which i thought would help performance.

silveriodine · Post by **silveriodine** » 02 Jan 2004, 07:55

just bumping this back up, does anyone have any ideas?

Guest · Post by **Guest** » 26 Apr 2004, 13:46

what was your reasoning for changing the mass air in the first place??

Airbox Thermostat? · Post by **Airbox Thermostat?** » 01 Jun 2004, 13:36

Change Airbox Thermostat (in the air cleaner housing). This part always fails (gradually), it's just a matter of time. I've found that they usually aren't working properly at 100K, and have failed completely by 150K. When it fails, hot pre-heated air (from the exhaust manifold) is directed into the Air Mass Meter all the time. This causes a loss of power, and eventually the AMM will fail. The AMM is an expensive part (around $200 rebuilt). The thermostat costs less than $20. It's a dealer part (also available from fcpgroton.com or ipdusa.com), the auto parts stores don't list it. The thermostat isn't too hard to change, you'll need "internal snap ring pliers". Remove the 10mm bolt on the AMM bracket, then unclip & remove the aircleaner cover. Change the air filter while you're at it, it's probably due anyway.