MAF sensor question
03-20-2010, 03:18 PM
#1
MAF sensor question So, I've been troubleshooting a problem my car has been having for the entire time I've had it. It has some power loss at around 2400 rpm partial throttle. It's been to the mechanic twice. The first time they replaced the fuel filter (it was clogged) and the second time they replaced the throttle position sensor. Neither of those fixed the problem. He says my plugs and wires are fine and so are the injectors. The front O2 sensors have also been replaced and he doesn't think it's the fuel pump because something would've shown up on the scan tool while he was driving it. My next idea is to replace the MAF sensor. I've cleaned it before and it didn't do much good (it's not de-screened). I'm thinking about replacing it with an 85mm SLP MAF sensor. My question is: is that gonna affect anything else with the car? It has not been tuned and it only has an SLP lid and a catback. Can I run one with a car that is nearly stock or should I just hunt down a factory one? No other mods on the car. Thanks in advance!
Cole
Cole
03-20-2010, 08:26 PM
#4
Do you have any friends that would let you try their MAF before you paid for a new one? That would be the next thing I would try, it sounds like every thing else have been checked. Also on a stock engine the 85mm MAF isn't needed, I made over 500hp on the stock MAF before I went to a SD tune. If your 85 MAF is not the problem I would still use it.
03-21-2010, 05:42 PM
#7
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usually if a maf goes bad it wont effect just one portion of the rpm band. Does it matter what gear you are in? manual or automatic? Try using a different gear and use the same amount of throttle and see if there is a power loss there also. That way you are at a different rpm but the same throttle position.
You cant feel anything else at any other rpm or throttle position??
You cant feel anything else at any other rpm or throttle position??
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03-21-2010, 05:59 PM
#8
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MAF goes out of fueling calculations past 4k RPM so you may be correct.
Easiest way to check it is to unplugg it and see how it runs after a few minutes to learn that it isn't going to use the MAF anymore. This puts it in a form of speed density, and will rely on primarily your O2's. If it does the same thing then you need to keep hunting and take the MAF being bad out of your list. If it runs fine then it's your MAF.
Don't bother with the SLP MAF if I remember correctly it has a resistor in it that makes tuning the thing a pain in the *** and will cost you in the long run.
Easiest way to check it is to unplugg it and see how it runs after a few minutes to learn that it isn't going to use the MAF anymore. This puts it in a form of speed density, and will rely on primarily your O2's. If it does the same thing then you need to keep hunting and take the MAF being bad out of your list. If it runs fine then it's your MAF.
Don't bother with the SLP MAF if I remember correctly it has a resistor in it that makes tuning the thing a pain in the *** and will cost you in the long run.
03-21-2010, 06:28 PM
#9
Ok, well I cleaned the MAF again and the throttle body with the proper CRC cleaners for each. My car is a 6-speed and it will jack up in any gear at 2400rpm whenever it chooses to. It doesn't happen always but it happens most of the time and isn't affected by temperature or anything else that I've noticed. WOT seems fine but when I hit 2400 partial throttle it just runs like a ricer. Is it possible that the O2 sensors might be dirty and that I should pull them and clean them? The car had a K and N filter when I got it. It doesn't have it anymore. Switched to a paper filter.
03-21-2010, 06:40 PM
#12
TECH Regular
Been running MAFless for 30K + miles. You know thats is how people will tune your car eventually, right? Unless your car has different heads, cam, and displacement change your not going to hurt anything at all.
In fact your running more of a risk by running it with a possibly bad MAF giving your car a rich or lean condition.
Or you can just keep throwing money at it randomly replacing **** that never needed to be replaced at all.
Strange power losses are normally, bad plugs/wires, fuel filter, O2's, MAF, and vacuum leaks.
In fact your running more of a risk by running it with a possibly bad MAF giving your car a rich or lean condition.
Or you can just keep throwing money at it randomly replacing **** that never needed to be replaced at all.
Strange power losses are normally, bad plugs/wires, fuel filter, O2's, MAF, and vacuum leaks.
03-21-2010, 09:24 PM
#13
Been running MAFless for 30K + miles. You know thats is how people will tune your car eventually, right? Unless your car has different heads, cam, and displacement change your not going to hurt anything at all.
In fact your running more of a risk by running it with a possibly bad MAF giving your car a rich or lean condition.
Or you can just keep throwing money at it randomly replacing **** that never needed to be replaced at all.
Strange power losses are normally, bad plugs/wires, fuel filter, O2's, MAF, and vacuum leaks.
In fact your running more of a risk by running it with a possibly bad MAF giving your car a rich or lean condition.
Or you can just keep throwing money at it randomly replacing **** that never needed to be replaced at all.
Strange power losses are normally, bad plugs/wires, fuel filter, O2's, MAF, and vacuum leaks.
Thanks for the input. You can see why I'm a little stumped, huh?
03-22-2010, 05:50 PM
#14
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cleaning the maf wont fix it if it is defective. I still dont think that is your problem. Is your car tuned?? Maybe have someone look at the tune and see if there is something funky in there.
03-22-2010, 08:10 PM
#15
The car isn't tuned. I had my mechanic hook it up to the scan tool and he found absolutely nothing but he is able to feel the drop in acceleration. I'm about to rule out anything related to the air/fuel component just because it's all been checked out.
03-22-2010, 08:24 PM
#16
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I had the same problem with my car and checked everything. I ended up unplugging the maf to see what happened and it was a huge difference. Id say give that a try. Worked for me, I just cleaned the maf and descreened it while I was at it.
Make sure you clean it good, I had to do mine twice.
Make sure you clean it good, I had to do mine twice.
03-22-2010, 08:28 PM
#17
Unplugged the MAF MAF goes out of fueling calculations past 4k RPM so you may be correct.
Easiest way to check it is to unplugg it and see how it runs after a few minutes to learn that it isn't going to use the MAF anymore. This puts it in a form of speed density, and will rely on primarily your O2's. If it does the same thing then you need to keep hunting and take the MAF being bad out of your list. If it runs fine then it's your MAF.
Don't bother with the SLP MAF if I remember correctly it has a resistor in it that makes tuning the thing a pain in the *** and will cost you in the long run.
Easiest way to check it is to unplugg it and see how it runs after a few minutes to learn that it isn't going to use the MAF anymore. This puts it in a form of speed density, and will rely on primarily your O2's. If it does the same thing then you need to keep hunting and take the MAF being bad out of your list. If it runs fine then it's your MAF.
Don't bother with the SLP MAF if I remember correctly it has a resistor in it that makes tuning the thing a pain in the *** and will cost you in the long run.
03-22-2010, 09:18 PM
#20
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if you didn't drive it then you dont know if the problem is still there. You will have to recreate the same situation. 2400 rpm part throttle. If the hesitation is still there, then the MAF isn't your problem. If the hesitation is gone, then the MAF is the problem.