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Old 01-16-2008, 05:17 PM   #1
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Question: Can I drive with disconnected MAF?

Yes, yes, I searched. But I did not find the answer I needed. This morning my mom needed me to change the oil in her Camry, so I got into my car turned it on like normal, then drove to the store, got the parts, came home. Then I noticed I did not have a needed tool, so I got back into my car and to the store and back. I did not notice anything bad or different. So an hour or two later I get ready to go to work, get into my car and turn it on...it starts but then it idles horrible and dies... so I crank it again...same thing, it starts fine...idles and dies...one more time, I start the car and it starts to die so I give it gas...alot of gas and when I keep it floor it hesitates a bit and then the RPS shoot up like normal. And if I keep it in the high RPS its fine... So I called into work to figure this problem out. So I checked all my spark plug wires and spark plugs. I made sure the cap and rotor were ok too. No success. I thought it could be my ignition control module. I came back inside to search this issue and I read and forgot to check the MAF and the TPS. So I got back out there and made sure everything is connected as it should (plug wires, ICM, etc) and I only disconnect the MAF, hit the ignition and she starts right up and it idled as smooth as ever. I don't think I've ever known it to idle that nice and smooth. I turn off the car. Plug the MAF, crank...crap. So I'm pretty sure its the MAF. I was wondering wether it was the MAF itself or maybe the burn off relay or power relay. I'm not sure if this is a MAF issue or a relay issue.
In hindsight I have noticed for a while that my car would sometimes idle a bit rough. Once or twice it cut off while at idle. Some surging and unsteady rpm at idle. Which I believe now to be teltale signs of a dying MAF...
Question: Do you guys think this is all indeed a dead MAF or could all this be a simple relay to the MAF thats making the MAF give off bogus readings? And also, how long can I drive the car without a disconnected MAF? Is this advisable? I think I remember something about an open loop mode? Can anyone educate me a bit on this? Thanks...
-hcr13
*edit, I also de-screened the MAF a while ago and I did not notice any driving changes at the time*
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Last edited by HCR13; 01-16-2008 at 05:21 PM.
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Old 01-16-2008, 08:40 PM   #2
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Re: Question: Can I drive with disconnected MAF?

Yes you can temporarily drive with the MAF sensor disconnected. I wouldnt do so more than the time it takes to drive to the parts store and get another one.
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Old 01-16-2008, 09:32 PM   #3
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Re: Question: Can I drive with disconnected MAF?

What is wrong, or what could go wrong with driving with a disconnected MAF?
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Old 01-16-2008, 09:32 PM   #4
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Re: Question: Can I drive with disconnected MAF?

Agreed, she'll run and drive OK with the MAF disconnected. For sure the check engine light will be on and you shouldn't drive this way any longer than is absolutely necessary, but you can definitely do it.

Do some diagnosis on the burnoff relay and replace as necessary, but I would say that even if that's found to be faulty, fixing that probably won't bring your MAF back to life at this point. Worth a try and definitely worth diagnosis before replacing the MAF but don't be surprised if you end up replacing the MAF at the end of the day anyway.
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Old 01-16-2008, 09:56 PM   #5
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Re: Question: Can I drive with disconnected MAF?

yeah, thats what I fear. she's also my daily driver. I get paid on Friday and plan to buy the cheapest one at the autoparts store, and order a nice aftermarket one online...when I get the online one, I'll return the cheapie one. Yeah, the SES light is on. But like I stated, the car seems to ride so smooth now. While in gear and idling it stays at a perfect 500rpms and about 700-750rpms in neutral. My fear is that I'll play $300 for a brand new MAF, connect it, and try to start it with the same hesitation. I also forgot to mention that it would backfire through the intake, I'd hear the pops out of the CAI...
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Old 01-17-2008, 02:26 PM   #6
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Re: Question: Can I drive with disconnected MAF?

Before you purchase a MAF check the throttle postion sensor. I had similar symptoms and after replacing the MAF there was no change. You can check the TPS with a digital meter and the process is desctibed on here someplace, maybe tech articals? The fault logic in my book took me to the MSF as being the problem. One of the members here suggested I check the TPS and he hit a bullseye.

My symptoms were: Idle like a Ford with a bad power valve, tended to fall on its face leaving from a stop but would move if lots of trottle was applied, general poor driveability. I can not recall the code it was throwing.

Check your local boards if you decide to get a new MAF, I am sure that in your area there is someone with a spare in the garage. (like me, now have two spares and the MAF was not the problem) Can you borrow one to try? If so you will now in 60 seconds or less if it is the problem. Again find the local guys, one of them will have a spare or will let you use his to determine if MAF or not MAF.
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Old 01-17-2008, 05:47 PM   #7
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Re: Question: Can I drive with disconnected MAF?

I don't mean to try to hijack your thread or anything, but how can a motor run without a MAF? Does the computer override it or something and go into some kind of safe mode or something?
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Old 01-17-2008, 06:40 PM   #8
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Re: Question: Can I drive with disconnected MAF?

Quote:
Originally Posted by jbpnumber03 View Post
I don't mean to try to hijack your thread or anything, but how can a motor run without a MAF? Does the computer override it or something and go into some kind of safe mode or something?
It runs of pre set tables of pulse width etc, stored in the prom. It will NEVER go into closed loop. Gas mileage will suffer. And with mine, with the MAF disconnected, there was a minor hesitation at throttle tip-in.
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Old 01-17-2008, 07:16 PM   #9
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Re: Question: Can I drive with disconnected MAF?

I'm pretty confident its not the TPS because right now it runs great without it (the MAF). Like I've previously stated, I've never seen my car run this smoothly ever. Even after all my upgrades. I've also replaced the TPS previously when I was having surgin issues (turned out to be ICM) but I took the opportunity to upgrade my whole ignition at the time. I'm planning of buying a cheapie MAF at the auto store and order a nice one online, and return the cheapie when I get the better one in the mail. When I connect the MAF right now, its like Trans Am Kryptonite. Runs like crap. I disconnect it, feels great. As far as performance, I haven't noticed too much of a drop, maybe a bit of horses because the ECM not "recognizing" the cold air intake. I haven't noticed about the gas mileage...yet. I've only been driving this for about a day. And will stop tomorrow once I pickup the new MAF... I might try the relays tonight... thanks for your help guys!
ploegi, you answered the million-dollar question for me!
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Old 03-18-2008, 10:44 AM   #10
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Re: Question: Can I drive with disconnected MAF?

Do you know if a MAF from an 86 TPI 305 will run ok in a 85 TPI with a 305? I can not find a used MAF for my 85 TA, and someone on the forum said it will be ok. Please PM me or email me at brandonandkarinunn@yahoo.com if you know. Thanks.

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Old 03-18-2008, 02:14 PM   #11
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Re: Question: Can I drive with disconnected MAF?

Hmm...I guess I need to disconnect my MAF just for kicks. I got a mystery backfire(but through the exhaust) when I rev just off of idle(among other wierd issues I wont mention here). I kinda want a performance one anyway so it would be nice if it is the cause!
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Quote:
Originally Posted by RedBravo View Post
Do you know if a MAF from an 86 TPI 305 will run ok in a 85 TPI with a 305? I can not find a used MAF for my 85 TA, and someone on the forum said it will be ok. Please PM me or email me at brandonandkarinunn@yahoo.com if you know. Thanks.

RedBravo
When looking at MAFs online recently (last night actually,lol) they all say for 86-up. One site actually specifically said, "this MAF will not work on '85's due to " Sorry, I stopped reading at that point since I dont own an '85. Im certainly not an expert on MAF's and this is just what I was seeing online but I would not vouch for it myself.

Last edited by TheRealBlkBird; 03-18-2008 at 02:17 PM. Reason: Automerged Doublepost
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Old 03-18-2008, 11:22 PM   #12
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Re: Question: Can I drive with disconnected MAF?

There is a default maf table in the 32 bins. It approximates the air flow. If these are close to what you need. Your engine will run, if not the farther from stock, the worse it will be.

A really educated (in ecm world) person could probably retune this table for all the changes. But why???? It is easier to just get a new maf sensor.

Somebody ran a year without a maf sensor. Search on "mafless" use the quotes.
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Old 03-18-2008, 11:22 PM
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