NuclearBacon Posted November 12, 2010 Share Posted November 12, 2010 But! When I go unplug the MAF, the car idles just fine... but has no power under load. I tried cleaning the connector to the MAF, as well as the connectors on the MAF. Didn't spray any MAF cleaner (saw it at the store) , but was curious about it dying under load... feels like it cuts out. I just did a complete head gasket on this car, with the engine removed. The car had overheated as it was a new vehicle bought by a friend of mine. I have no idea the previous history of the car besides it showing up to my house overheated. Could I have possibly skipped a tooth on the timing belt? it seems to idle ok with no MAF connected... so i figured I timed it correctly... Ideas? Oh! and the MAF doesnt throw a code when its plugged in (and i rev it to keep it running, trying to get it to throw a MAF code with it plugged in) I have cleared the computer and the only code it throws is the MAF when its unplugged. Quote Link to comment Share on other sites More sharing options...
94Loyale Posted November 12, 2010 Share Posted November 12, 2010 Def sounds like MAF to me, if they fail bad the motor won't idle. Other times the failure isn't as evident. Also check to make sure you have the big tube the goes from the IAC to the intake tube hooked up. It won't idle with that unhooked also. But if it idles with the MAF unplugged then I'd figure that's the problem. Swap another one on and see what happens. That's the wonderful part of OBD, when something actually fails it never shows up Quote Link to comment Share on other sites More sharing options...
Ricearu Posted November 12, 2010 Share Posted November 12, 2010 unplug the tps also, should tell the computer to "limp home" then you can plug the tps back in and shoud run a little better. if it runs worse with the tps plugged in, try unplugging it and plugging in the MAF Quote Link to comment Share on other sites More sharing options...
zacyork Posted November 12, 2010 Share Posted November 12, 2010 yup mass air flow sensor. or you have a leak between your sensor and throttle body. both will give you the same problem. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 12, 2010 Share Posted November 12, 2010 Unplugging the MAF puts the ECU in "Limp" mode. It will run but won't be too happy about it. Basically it ignores all of the sensors on the engine so if one is way out of whack you can still manage to drive the car to a safe location (shop, home). This doesn't automatically mean the MAF is bad. Just means that the ECU is ignoring everything else when the MAF is unplugged. Double check all of the hoses that attach to the intake tube, to make sure they're all tightly attached and clamped where needed (such as on the throttle body). Quote Link to comment Share on other sites More sharing options...
NuclearBacon Posted November 12, 2010 Author Share Posted November 12, 2010 Also check to make sure you have the big tube the goes from the IAC to the intake tube hooked up. Swap another one on (MAF) and see what happens. The IAC is connected. I have a MAF from the Ej22T legacy. unplug the tps alsoif it runs worse with the tps plugged in, try unplugging it and plugging in the MAF Defninilty going to give this a shot or you have a leak between your sensor and throttle body. both will give you the same problem. interesting! (writes down as well) I will check. This doesn't automatically mean the MAF is bad. Just means that the ECU is ignoring everything else when the MAF is unplugged. Double check all of the hoses that attach to the intake tube, to make sure they're all tightly attached and clamped where needed (such as on the throttle body). Correct. The reason I went for the MAF in the first place with no codes, is I remember fixing an EA82 that wouldnt run, the PCV valve had gone wonky and oil pressure built inside the crankcase pushing oil up into the intake plenum AND dripping all the way down into the MAF! Unplugging the MAF, and starting on a whim, allowed the car to enter limp home mode (or whenever there is a check engine light, = limp home mode) and ...allowed me to limp home. I'll go try each of these and report back! Thank you! Quote Link to comment Share on other sites More sharing options...
987687 Posted November 13, 2010 Share Posted November 13, 2010 Having a CEL doesn't always put it into limp mode. And I've had a MAF fail that didn't throw a code, didn't even make it idle bad. First thing that tipped me off was it started idling at 730 RPM, not 700. And later it started running like crap. I rarely have a CEL code that ends up being useful in fixing something.... I just get censors reading bogus like the MAF but not throwing a code. As far as I've found, there's a few levels of limp mode. If you loose a VSS signal it won't rev over 3.5k or 4.5 or something, but otherwise run fine. Another mode is it ignores all censors and goes into a very basic mode of running. Very rich, both rad fans always on to keep it from overheating, etc. I think I got this when I lost my CTS. Quote Link to comment Share on other sites More sharing options...
94Loyale Posted November 16, 2010 Share Posted November 16, 2010 Soo...What was the problem? Quote Link to comment Share on other sites More sharing options...
NuclearBacon Posted November 16, 2010 Author Share Posted November 16, 2010 TPS + MAF = Car ran crappy, dies TPS (no MAF) = Car idles, dies under power, but runs otherwise. MAF (no TPS) = Car idles high, dies. IAC Plugged in No leaks from MAF to throttle body All Vaccum hoses good. I didnt try to move over my turbo legacy MAF, since I saw it was 5 wire (92 legacy), then I went to the junkyard, grabbed a MAF that looked identical off of a 94 legacy (again 5 wire, but looked identical) wanted to take it home to try, and when I got to the counter, the pick a part yard wanted $75 bucks. SEVENTY FIVE BUCKS. WTF. I left it there. Question 1: Can I use my turbo legacy MAF to test? Question 2: Anyone got a MAF they're willing to sell for $20 + shipping? Quote Link to comment Share on other sites More sharing options...
NuclearBacon Posted December 28, 2010 Author Share Posted December 28, 2010 Idle air control valve... the hose was disconnected. car runs perfectly I did need that MAF, cars running great!!! Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted December 28, 2010 Share Posted December 28, 2010 Good to hear! You still need a good MAF? I can get them for under $30 from the "local" U pull (hour away) Is it the AA160? Quote Link to comment Share on other sites More sharing options...
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