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Poor running and check engine light after cleaning maf

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Old 08-16-14, 04:47 PM   #1
Largefarva
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Default Poor running and check engine light after cleaning maf

I had my maf out today to install an air filter so I cleaned it with some intake cleaner, then let it air dry. Got in the car later and my check engine light is on, also my trac off light is on. The car starts and runs good but at light throttle is surges badly-like the ignition is cutting out it also smells like its running rich, seems to have less power as well. Gonna check codes tomorrow, but it ran fine and the lights went out during a long highway ride.
Any help would be great, I'm guessing probably a maf issue or maybe the wiring?
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Old 08-17-14, 05:50 AM   #2
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Forgot to add, this is on a 1993 LS 400 with 330km.
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Old 08-17-14, 05:56 AM   #3
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Quote:
Originally Posted by Largefarva View Post
I had my maf out today to install an air filter so I cleaned it with some intake cleaner, then let it air dry. Got in the car later and my check engine light is on, also my trac off light is on. The car starts and runs good but at light throttle is surges badly-like the ignition is cutting out it also smells like its running rich, seems to have less power as well. Gonna check codes tomorrow, but it ran fine and the lights went out during a long highway ride.
Any help would be great, I'm guessing probably a maf issue or maybe the wiring?
Did you unplug the battery or the ECU fuse for at least 10 minutes? Did you touch any of the metal prongs on the maf sensor? Did you let the maf sensor completely dry before reinstallation? Did you re-attach the wiring harness for the maf? <--- very easy to overlook.

CEL comes on whenever the car is turned on without the wiring harness plugged in for the MAF and won't go back off until you reset that code or the ECU.

My suggestion is to check all the connections first. Then pull codes. Then reset the ECU.
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Old 08-17-14, 06:04 AM   #4
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Reset the ECU after the first drive, same thing. I just sprayed through the honeycomb, I couldn't have touched anything, it dried for at least and hour before starting the car. It is plugged in. Gone pull codes shortly.
Thanks.
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Old 08-17-14, 06:43 AM   #5
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Code 31, maf signal.........are these mags sensitive to cleaning sprays?
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Old 08-17-14, 07:02 AM   #6
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I read somewhere MAF is very sensitive to certain cleaning spray. cant remember where. if it is back to normal (after long highway trip), then why worry
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Old 08-17-14, 07:13 AM   #7
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^Was fine and no light on the highway, then on surface streets/lower speeds the problem returned and remains. The code returns within 10 seconds of running.
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Old 08-17-14, 07:18 AM   #8
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Code 31, maf signal.........are these mags sensitive to cleaning sprays?
Extremely sensitive. In most cases it isn't even necessary to clean them on these cars. Good news is many people have reported no change in performance from unplugging their maf.
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Old 08-17-14, 08:02 AM   #9
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Thanks, gonna try that today, but needs to be fixed regardless.
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Old 08-17-14, 03:17 PM   #10
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you destroyed the maf most likely. 1st gen cars use an optical reading karmen vortex AFM (not a MAF) and are EXTREMELY sensitive to dirt/solvent damage.
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Old 08-17-14, 03:35 PM   #11
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^Lol, great, its only a $500 part......car is likely headed for scrap, damn
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Old 08-18-14, 02:16 AM   #12
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^Lol, great, its only a $500 part......car is likely headed for scrap, damn
buying a working used one off ebay will not be that bad
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Old 08-18-14, 02:18 AM   #13
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Quote:
Originally Posted by ClassicSC3 View Post
moral of the story?! what is the skinny on what to use to clean your MAF. My 95 has not had the clean done and it's being held back, as a result. OP: dont be scurred or scourged cause you had the courage to open your engine up so that deserves kudos. i can't turn my wrench and furthermore, just holding the wrench hurts.
your 95 has a hot-wire MAF sensor. using MAF cleaner properly will not harm it.

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^Lol, great, its only a $500 part......car is likely headed for scrap, damn
they're like $100 from junkyards/ebay. just buy one warrantied. the mk3 supra guys buy/sell them all the time for like $50-80.
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Old 08-18-14, 04:16 AM   #14
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Thanks. So which years/models will interchange with mine?
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Old 08-18-14, 05:54 PM   #15
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for safety, stick to '93-94 only.
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Old 08-18-14, 05:54 PM
 
 
 
 
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