A couple questions (possible MAF issue)

[Wolf]

Hey friends, instinct came with the near 70 degree weather we’re having in Nebraska this week, naturally i want to drive my Boxster

Well ive had her stored in the garage for the past month due to snow and ice, and only drove her once in the past month. Didn’t have any issues then, just connected my battery as normal (i store it in a warm place as i have for the past few year without any issues) and it started right up and i had a nice 70+ mile drive to and from my destination.

Well today, did the same, but immediately the car died. Never dealt with that before, and naturally i started searching online for remedies, which included:
-Swapping back up relay and fuel pump (no change)
-Swapping out a few other of the smaller fuses (none were broken, just the what if)
-Disconnected MAF and tried starting (didn’t start at all)
-Reconnected MAF after wiping it down (there was a residue on it, probably oil) mind it still looks brand new on the inside, the actual unit
-Waited a while because i was still looking at online solutions, went to start it up and boom shes good to go


I let it run for a good 15 or so minutes before taking a drive which all seemed normal. Brought it all up to temps and came back home and here I am.

The second question regards to a small bog when coming to a stop, I noticed it heavily when the AC is running, and on a warm day it wont go below 800 RPM, but with it off its going a little lower for my liking and a little uncomfortable knowing it could die on me possibly in the middle of the road again.

Any responses would be amazing, i apologize in advance for the long post and rambling.

[blue62]

Originally Posted by Wolf

Hey friends, instinct came with the near 70 degree weather we’re having in Nebraska this week, naturally i want to drive my Boxster

Well ive had her stored in the garage for the past month due to snow and ice, and only drove her once in the past month. Didn’t have any issues then, just connected my battery as normal (i store it in a warm place as i have for the past few year without any issues) and it started right up and i had a nice 70+ mile drive to and from my destination.

Well today, did the same, but immediately the car died. Never dealt with that before, and naturally i started searching online for remedies, which included:
-Swapping back up relay and fuel pump (no change)
-Swapping out a few other of the smaller fuses (none were broken, just the what if)
-Disconnected MAF and tried starting (didn’t start at all)
-Reconnected MAF after wiping it down (there was a residue on it, probably oil) mind it still looks brand new on the inside, the actual unit
-Waited a while because i was still looking at online solutions, went to start it up and boom shes good to go


I let it run for a good 15 or so minutes before taking a drive which all seemed normal. Brought it all up to temps and came back home and here I am.


The second question regards to a small bog when coming to a stop, I noticed it heavily when the AC is running, and on a warm day it wont go below 800 RPM, but with it off its going a little lower for my liking and a little uncomfortable knowing it could die on me possibly in the middle of the road again.

Any responses would be amazing, i apologize in advance for the long post and rambling.

What year is the car?
How many miles?
You mention a possible oil reside on the MAF.
Are you running a stock air filter or after market???

If it is a year 2000 or newer you have the e-gas throttle so if you disconnect your battery you need to recalibrate your throttle.

Second thing, never touch or wipe any part of a MAF sensor other than the base.
Clean it with a MAF sensor spray cleaner made for MAF sensors. They are very sensitive, touching them or wiping them damages them then they don't function properly.

[BYprodriver]

I recommend
you buy a new Bosch MAF & install in your car. If it runs better leave it in & toss the old one. If there is no improvement keep it because you will need it sometime & it's good to have for issues like this

[blue62]

WOLF:

Another thing I failed to point out in my first post.

If you are disconnecting your battery the DME/ECU drops certain settings.
They are more or less reset to a base line setting once you reconnect the battery.
One of those settings or conditions is fuel trim.
So since fuel trims are a "learned" condition or setting, the ECU/DME has to relearn the fuel trims once the battery is reconnected and the car has gone through several drive cycles.
So sometimes the car runs differently until the DME/ECU relearns the old settings or conditions.

[Wolf]

Originally Posted by blue62

WOLF:

Another thing I failed to point out in my first post.

If you are disconnecting your battery the DME/ECU drops certain settings.
They are more or less reset to a base line setting once you reconnect the battery.
One of those settings or conditions is fuel trim.
So since fuel trims are a "learned" condition or setting, the ECU/DME has to relearn the fuel trims once the battery is reconnected and the car has gone through several drive cycles.
So sometimes the car runs differently until the DME/ECU relearns the old settings or conditions.

Yes i really need the trickle charger that plugs into the lighter outlet. I have one of the battery tender things from the parts store but i do not trust keeping it plugged in 24/7.

[blue62]

So about the bog you mentioned when coming to a stop with the AC on.
That sounds pretty normal. The engine has extra load on it from the AC compressor.
I will see if I can find an RPM spec. for idle with AC on.

Couple of questions:

Is it a stick or automatic transmission.
What is the RPM at idle with AC off an at operating temp.
If you step on the brake at idle with AC off, does RPM change -vs- not stepping on the brakes.

[Wolf]

Originally Posted by blue62

What year is the car?
How many miles?
You mention a possible oil reside on the MAF.
Are you running a stock air filter or after market???

If it is a year 2000 or newer you have the e-gas throttle so if you disconnect your battery you need to recalibrate your throttle.

Second thing, never touch or wipe any part of a MAF sensor other than the base.
Clean it with a MAF sensor spray cleaner made for MAF sensors. They are very sensitive, touching them or wiping them damages them then they don't function properly.

Its a 1998 base with 124k miles on it. Recently changed the air filter to an brand new one, stock.
The residue was on the outer rim that goes inside its housing. Plastic part only, didn’t touch any of the rest of the piece, was extremely careful with it. Did notice some dust or whatever where the pins are, should probably spray that with some MAF cleaner.