The other night, car ran fine. Next morning for work, it wouldnt start(crank, but no start).

Strapped it on a scanner, and it gave me two MAF codes. So the next day, i tried it on a road test. No MAF codes, but it gave me the 0300 for random misfires.

So will a bad MAF let the car start, let alone run and create misfires?

thanks

 

Yes, a bad MAF will cause missfires. If your car starts try unplugging the MAF and see what it does, when I did this on mine my car cut off, so I knew it was ok. With a bad MAF it will send messages to the PCM saying that its not getting enough air, or too much and the computer compensates causing the missfire. Also try jiggling the wires connected to the MAF, they can come loose very easily.

 

So you're saying that if the MAF is ok, the car is suppose to cut off if you unplug it. BTW, my car threw the random missfire code as well.

 

It may not cause every car to stall out, but it will diffinately run very rough to where it will almost cut off. Also, check all connections on the elbow and make sure it goes over the TB all the way, that could also throw a code. Mine stalled one day and wouldnt start and I noticed the elbow was folded under the TB, it didnt give me a code, but I have OBDI, which is less sensitive.

 

that is somewhat correct. I know for sure if u have obd1 you can run without a maf altogether. You may ask how do i know this. Because I have been doing it for about a month now, since mine was malfunctioning, I unplugged it. It throws a ses code, and it reverts the car back to speed density like the 93s had in the computer. My car runs smoothly without it plugged in, i just get worse gas mileage (as if it could get worse). I am only doing this because i am waiting for my new one to arrive. My car would stumble when driving normal. So, i unplugged it and it went away. Your car will not react good at first to the maf being unplugged leave it sit for a minute and it should recover. After that it shouldnt give u troubel, but u still need to get a new maf. However dynomight with all the mods u got going on, i wouldnt go my route. I would borrow an maf or go to a salvage yard and get one out of a 96-99 gmc or chevy with a vortec 350 because they have the exact same part # as ours. Thanks, Michael

 

I once unplugged my MAF and the car ran good. The sound was a little muffled though.


Marvin

 

Did you guys unplug the MAF with it running? I unplugged mine while running and my car cut off.

 

I turned the car off first.

 

well, thanks fellas for the quick response, and help!

a little more info. The car is far as hell from stock now, so i know diagnosing is gonna be more involved. The car didnt start the first day. The second day checked the plugs, and all were fouled (black and gas soaked). After cleaning the plugs, i finally forced the damn thing to start. While warming up for road test, i hooked up the scanner, and found cyl #2 & 7 misfiring to the tune of about 2000 in 15 minutes. Idles sounds off from normal. Upon driving, ses lite flashed at about 30 mph, 2500 rpm orso. Didnt stay on, and got the p0300 code. MAF code hasnt come back since, so i wont start there.

I have a friend coming by tonite, so we will get closer to figuring this problem out.

I know that misfires are sucha broad problem (as far as causes), so it could be anything, but i will let you guys know what i found when i find it.

thanks again
john