MAF sensor replacement

1997 NISSAN HARDBODY
247,000 MILES • 2.4L • 4 CYL • 2WD
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JCLEMO
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I just replaced my MAF sensor January 3, 2019. Today the truck started doing the same thing it was doing before I replaced it. Engine surge at 2,500 rpm.
Unbelievable one of the contact wires is gone. This sensor cost me $127.00.
Cardone is suppose to be top quality part. Mean time my MAP sensor was bad also. Could the bad MAP sensor be causing the MAF sensor to burn up? Why is this happening? I had to take my oil pump back out and retime it with the distributor because the truck would start but would not accelerate. The rotor I noticed was pointing at about one o'clock instead of pointing directly to the number one plug wire. So I removed the pump and the spindle.
And reinstalled it with someone holding the rotor at twelve o'clock.
It fell right in place and when I started the engine.my problem was solved. But then I find my MAF sensor is bad again. What would cause the new sensor to default? I'm replacing the MAP sensor before installing a new MAF sensor. And hopefully this one doesn't go bad too. The new one lasted a month. No clue please help. JC
Feb 14, 2019 at 11:45 AM
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SCGRANTURISMO
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Hello,

MAF sensors use a thin delicate platinum wire at the heart of a complex circuit to measure the air entering your engine. Any unwanted debris that makes it past your air filter can potentially damage this wire. Even insects like bees can damage the wire. I would inspect my air filter and inlet tube making sure there is no leak that would allow foreign particles access to the MAF sensor. Also you could have just got a ,defective part. I would inquire about any warranties that might be available for the MAF sensor you just purchased. I have also included this link to a helpful guide. Go through it as it should help you in the future.
https://www.2carpros.com/articles/mass-air-flow-service

Thanks,
Alex
2CarPros


Feb 14, 2019 at 7:12 PM
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JCLEMO
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Thanks Alex My sensor was warranted.
Lifetime so I replaced it and fixed the problem. Also replaced the MAP as well.
I still have a misfire at lower rpm and my number four plug is fouling it's very black. Any input greatly appreciated. Thanks JC
Feb 14, 2019 at 9:56 PM
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JCLEMO
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Alex, I had some timing issues and think I have it corrected.But I'm concerned that I may have bent a valve or valves by starting the engine out of time.Though it wasn't that far out of time and would only idle no acceleration. How can I tell if I damaged my head? Thanks. JC
Feb 14, 2019 at 10:02 PM
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SCGRANTURISMO
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You will have a serious miss. You would probably hear some kind of mechanical noise at the affected piston, and your Malfunction Indicator Lamp (MIL) or "check engine" light would be illuminated and flashing. Your vehicle has an interference engine in it. Did you turn it over a few times by hand after getting it back together?

Thanks,
Alex
2CarPros
Feb 15, 2019 at 5:13 AM
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JCLEMO
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Yes I did making sure marks lined up . I ran it for about twenty minutes before all the air come out of the lifters. Now it's running very quiet. No ticking or weird noises of any kind. Just that annoying misfire. I replaced all the injectors last month but then removed the head again to have an issue fixed with manifold studs that was not addressed when the head was resurfaced. Thus the injectors we're subjected to a month of sitting on my work bench. Number four plug is fouling. I think this is my misfire. Your opinion please.
Feb 15, 2019 at 6:27 AM
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JCLEMO
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Alex,
Also, concerning my engine light it stays on. Ever since I bought this truck with low mileage seventeen years ago. Must be a good little light bulb. Anyway it has gone off and come back on. But never flashing.
Feb 15, 2019 at 6:31 AM
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SCGRANTURISMO
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Hello,

Okay, that's good. A flashing MIL indicates a catalyst damaging event, i.e. very bad for the mechanical's of your engine. What is your plug fouling out with? If you could take a picture and upload for me that would be great. If not, please give me a good description.

Thanks,
Alex
2CarPros
Feb 15, 2019 at 1:20 PM
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JCLEMO
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Sorry, but I'm not sure what you mean by fouling out with. I just noticed the number four plug was very black and the other three seemed to be normal. Thus my thinking this is the misfire. By the way can you visually see a bent valve? My engine runs too good other than the misfire and loosing rpm when holding the throttle steady at 2,500 rpm for it to have any valve damage. But I am going to pull the head back off again and inspect it. Which brings me to another question. Do I need to replace the head bolts again because of prior stretching? I just replaced the head bolts. But I've heard they need replacing if you remove the head. thanks again. I appreciate your time and response greatly. JC
Feb 15, 2019 at 3:25 PM
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STRAILER
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Before you plug the head off lets do a compression test, you might have a shorted fuel injector.

https://www.2carpros.com/articles/how-to-test-engine-compression

This guide can help as well:

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Please run down these guides and report back.
Feb 18, 2019 at 12:23 PM
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JCLEMO
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Please advise me of how to inspect the head when it's removed. The cylinder test was fine. Thanks. JC
Feb 18, 2019 at 1:36 PM
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JCLEMO
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Sorry for all the random emails but my phone is not cooperating today. I did the pressure test all is well. But I need to know what to look for when I remove the head. I'm not sure what I'm looking for exactly. I'm sure there's no visible bent valves but the steady low to mid range misfire leads me to believe it's timing or valves. But I'm pulling timing cover off as well and inspect my marks and mating dots on both gears. How many rotations does the crankshaft turn before the dots line up with the special links on the chain? Is it 16 complete revolutions? I think the crank turns two to one on camshaft is that correct?. Thank you JC
Feb 18, 2019 at 1:45 PM
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STRAILER
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Now that this thread has changed into a misfire issue lets start a new question.

Please post your new question here, you must be logged in.

https://www.2carpros.com/questions/new

Cheers, Ken
Feb 19, 2019 at 10:57 AM
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JCLEMO
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I wasn't trying to change to spark plug problems. But that's okay I'll figure this out.
Feb 19, 2019 at 4:24 PM
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STRAILER
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We can together, just post a new question please. :)
Feb 19, 2019 at 5:18 PM