Rough Idle After MAF clean

[sjbsuperman1425]

cleaned the MAF today as i suspected it as my culprit for my idle hunting. removed MAF from housing, cleaned with MAF cleaner, let sit, then reinstalled..ran like crap after that. it idles at 700rpm and runs very rich. unplugging the MAF helps the idle. is my MAF junk, or fixable? i tried pulling codes but kept getting the code 55 (no code code)..so im really stumped/stressed. any help guys? thanks alot

[Ca_Silvia]

Now that you've done this, it has to be a vac leak. I know you said you have checked that but it just has to be the only thing left.

I have a spare ca maf for sale if interested

[sjbsuperman1425]

MAF code is now present, and unplugging it helps, like i said. on startup it idles at 1500rpm or so, then idles down to 700 and runs like sh1t, so i dont believe it would be a boost/vac leak

[xX RB Xx]

too much fuel...

need to re-adjust fpr..

[ZOMG.SR20]

its a vac leak.

[240dx]

a vac leak would cause a higher idle. It sounds like too much fuel or your maf. Try testing your maf with an OHM meter and a Volt meter.

[sjbsuperman1425]

the wiring is good for sure, tested that. but haven't got around to testing the sensor just yet. im unhooking the battery tonight to reset the ECU and then go from there. could the MAF cleaner have shorted out the sensor?

[xX RB Xx]

^ no

[sjbsuperman1425]

btw, i have a nismo fpr and its set per FSM and is 100% correct. injectors are within specs, plugs are a little fouled by now. on inital start up at 1400 rpms it is at 19"hg so i dont believe its a vac leak. the only code i get or symtpom i get is the MAF code or Limp Mode.

so either the MAF is junked after cleaning, or i need to reset the ECU (im leaving it unhooked overnight). a engine performance instructor at my college said that the MAF cleaner could have shorted it out, but i doubted that since there really isn't a way for it to do that is there?

[OutToWinPAHC]

What did yo use to clean the MAF. Please dont say brake clean? It leaves a film on the element if so. Only mas air cleaner should be used on a mass air sensor.

[sjbsuperman1425]

What did yo use to clean the MAF. Please dont say brake clean? It leaves a film on the element if so. Only mas air cleaner should be used on a mass air sensor.

i used mass air flow sensor cleaner.

[ZOMG.SR20]

btw, i have a nismo fpr and its set per FSM and is 100% correct. injectors are within specs, plugs are a little fouled by now. on inital start up at 1400 rpms it is at 19"hg so i dont believe its a vac leak. the only code i get or symtpom i get is the MAF code or Limp Mode.

so either the MAF is junked after cleaning, or i need to reset the ECU (im leaving it unhooked overnight). a engine performance instructor at my college said that the MAF cleaner could have shorted it out, but i doubted that since there really isn't a way for it to do that is there?

you can if you use too much and/or leave the ground hooked up to the battery or not letting it dry enough before reinstall

[sjbsuperman1425]

i accidentally got some on my hand during cleaning, and it dried pretty fast, and i was sure to give it like 3-5 minutes to dry. i also unhooked it from the car and took it out of the housing.

someone said there could be a residue left on the wires, causing it to read funny? if so, could i use like 70% isopropyl alcohol to get that off and clean it? i'll probably try it anyway as i dont really have the cash for a new MAF, but if i have to i have to.

[sjbsuperman1425]

bump for advice before i leave school to work on this problem..

[S13Teddy]

[sjbsuperman1425]

i dont get it?? lol but thanks for the free bump..

[Steady_One_S13]

Use a small paint brush with small soft bristles to clean the maf. Spray some more cleaner and try it out again.It worked for me on my SR maf.

[sjbsuperman1425]

Use a small paint brush with small soft bristles to clean the maf. Spray some more cleaner and try it out again.It worked for me on my SR maf.

the MAF wires themselves were dirty before, and are spotless now. im going with the Q-Tip and 91% isopropyl alcohol method tomorrow after school or tonight. it ran good before all this, just didn't idle that great, now it barely idles and runs like crap hopefully this works!

[S13Teddy]

i dont get it?? lol but thanks for the free bump..

I don't know. I just thought that maybe a picture of a dirty sock with a needle going through it might somehow help you.

[sjbsuperman1425]

so does anyone think the MAF cleaner could have left a residue that the Isopropyl Alcohol could get rid of?

[xX RB Xx]

too much fuel pressure....

what does the car max rev too?

if it was the maf.. it would be 2.5k

also check your plugs and coil packs.

[sjbsuperman1425]

too much fuel pressure....

what does the car max rev too?

if it was the maf.. it would be 2.5k

also check your plugs and coil packs.

fuel pressure is at 28psi at idle (its what FSM says)when i had it plugged in, it would idle rough and rev to around 5k or so and be super rich, after unplugging it, idles fine and revs max at 2100prms. plugs were shot, cleaned them, were shot again, installed new plugs. coilpacks are all working 100%.

[xX RB Xx]

your maf is ok..

you have a problem somewhere else.......................................

try 36psi at idle.

[xX RB Xx]

also check your bov.. it could cause your idling problem but not the rich problem.

[sjbsuperman1425]

it fouls plugs at idle with 28psi, idles at 800 and pulls 10"Hg.

i also dont have a BOV (i know i know) and there are no vacuum leaks. pulled 19"Hg. right before i cleaned MAF. Also, with MAF plugged in, will idle at 1500rpm for a second, then fall. if i tap gas, it goes back up, idles fine and then falls..maybe sticking throttle, TPS, idle switch? why would this only show up now after cleaning maf though?

[xX RB Xx]

get the car to operating temps and tell me what it idles.

make the car idle if you have too.

[sjbsuperman1425]

alright.

im going to reset the codes, clean the MAF with isopropyl alcohol (just incase), and let it idle. and reach operating temps. i will report back today probably around 3 or 4pm. thanks for all the help. i hope i can figure this out

[sjbsuperman1425]

ok, well i just went and started it, no codes before startup..after startup, it idles fine like its warming up but code 12 (MAF) is present? if there is a film/residue on it, would it cause the code to present, or does this basically mean i need a need a new one?

[OutToWinPAHC]

You have been dealing with it for a few days, just go get a new one. Or try a junk yard. Altimas also have KA's so it could be a cheap fix.

[sjbsuperman1425]

You have been dealing with it for a few days, just go get a new one. Or try a junk yard. Altimas also have KA's so it could be a cheap fix.

yea i tried the 91% alcohol and it didn't work. today was the first day i worked on it besides monday morning. but i dont have a KA (CA18DET) so no good there, and junkyards where i live barely carry any imports so im screwed twice! im looking for a new CA18DET MAF right now. Thanks everyone for your brainstorming..

MAF Cleaner = Bad Ju Ju