Car Starts, Then Slowly Dies Out - MAF?

[revenger]

Sorry about the long post, heh, I'm good at that

First off, it's not my car, it's a friend of mine. '97 3000GT Base, ATX, ~120k miles

Some history:
He's been telling me about his car not running right and he had some electrical problems and yeah, basically his car needed attention badly.

He brought it to a shop and had them "fix everything that's wrong with it so it runs" (I believe that's pretty close to what he told them)

The shop said he needed an alternator, so they did that as well as the PS belt. They also fixed his cracked downpipe (He probably needs new motor mounts). I'm not 100% sure, but they may have also put in a new starter for him. He also had a CEL for "Auxiliary Emission Control" (P1400? or P1600? one of those I think), they fixed that.

He also bought a new battery and installed that himself.

Fast forward to last week...

He texts me saying "how hard is it to do the battery wires?"
Me: The wires off the battery itself aren't too bad, what's wrong?
Him: The battery isn't holding a charge"
Me: Well, the wires could be part of it, but it could be a lot of things, check the fuses, alternator, etc.
Him: Come look at it

I looked at it today and it started up ok, idle bounced around from 500-800RPM. I pulled voltage readings with a multimeter and he had 14.3V while idling, and 12.4V while the engine was off (meter was at the battery).
I didn't rule out the charging system completely, but I didn't go probing around to verify it, I simply moved on to noise diagnostics.

He has a couple noises that I don't seem to have on my 99. He had a sucking/howl kind of sound coming from the AC compressor area (I did the long screwdriver stethoscope trick and ruled out the PS pump, but I couldn't verify if it was in fact the AC compressor. He also had a light sort of knocking/clacking sound. I couldn't tell if it was lifter tick (since my 99 doesn't have it ), or something piston or bearing related or something since it is more prominent on the driver's side of the engine than on the passenger's side of the engine.


Now, the reason I told you all that is because I don't know if it will make a difference in the next part...

NOTE: These video's are for audio purposes only, I wouldn't pay too much attention to the actual picture (And sorry ahead of time, but I had to use my cell phone to do it, so the audio isn't perfect.)

His idle is this (you can hear that clacking noise too, it that lifter tick or something different?):
The car was warmed up when I took the video, and at the end, it dies out itself.



So then it hit me: MAF sensor
I unplugged it and we got this at idle (again notice the clacking sound):
It ran ok, and didn't die out on its own.




So I made one more video, we started it with the MAF plugged in, the idle was crappy, then I unplugged it, and the idle smoothed out. (You can also hear that howling noise I mentioned above in this video as well):



After researching this "test" of the MAF and how if unplugging it helps the car idle better, it this enough to say he needs a new MAF? And he was wondering if he can drive around with the MAF unplugged, I told him yeah, but you might suffer in gas mileage. (He only needs to drive it to his new place which is about an hour away)

Also...(sorry!!) he doesn't have plates for it, the plates are on his new car, is there any way he can drive the car to his new place without having to register it and get new tags? He has the title, just not registration or plates for it. He needs to move it because he's trying to sell it and wants it closer to him to he doesn't have to drive an hour to get to the car every time. Could he just put on his current plates from his other car and put a sign in the window that says "in transit"?


Thanks in advance, and again, my bad on the long read...

[revenger]

[jstarr427]

I think you'd be fine with driving with your old plates as long as you follow the rules.

As far as the issue, it does sound like a typical MAF issue. Try swapping the one from your car into his and see if that fixes the issue. If it does, then there you go.

oh and FYI The lifters in SOHC's don't tick typically like the DOHC does.. and you're 99 has the same lifters that mine and his do it's an SOHC!

[revenger]

Originally Posted by jstarr427

I think you'd be fine with driving with your old plates as long as you follow the rules.

As far as the issue, it does sound like a typical MAF issue. Try swapping the one from your car into his and see if that fixes the issue. If it does, then there you go.

oh and FYI The lifters in SOHC's don't tick typically like the DOHC does.. and you're 99 has the same lifters that mine and his do it's an SOHC!

Alright cool, thanks for the info.

Anyone else have anymore input on this?