Anyway to test a Mas Air Flow Sensor?

[Mykul]

Sorry for the long story.

We got the car from my wife's dad. He wrecked it a few years ago. (fell asleep, ran off the road, hit rail road tracks- wiped out the radiator and condenser(sp?)this is all on the to do list, or better yet the re-do list)

It sat in his garage until last year when he tried to fix it up to trade it in. The dealer only wanted to give him $1200, so he gave it to us.
So I get it and it has a check eng. light.
We drove to back from Utah with the light on, it ran fine.

I have it scanned and it had three codes (p1128 and I can't find the sheet on the other two- I know, I know) The diagnostic sheets had possible causes on them and the only thing they all had in common was the O2 sensor and the MAF sensor. I bought a scanner and cleared the codes to see if they reset. As soon as I cleared the codes it idled badly and bogged down when I started off. This only lasted for a minute and I wrote it off as driver error. I drove around for most of the next day when the light came on while on the freeway. I double checked the code and all that was there was the P1128. So I changed the upstream O2 sensor and cleared the code again. Big mistake! Now the car has an extremely bad idle, when I press the gas, it bogs down and backfires, then it will rev up. I can’t drive it enough to reset the light.
I inspected the vacuum lines for cracks or loose fittings and found none. I did find that the wire connection to the MAF was cracked and the wires looked like they weren’t making a good connection. I replaced that and still no dice.

I don’t want to keep throwing parts at this, but the next thing in my sights is the MAF.

[Canadianbugin]

Originally Posted by Mykul

Sorry for the long story.

We got the car from my wife's dad. He wrecked it a few years ago. (fell asleep, ran off the road, hit rail road tracks- wiped out the radiator and condenser(sp?)this is all on the to do list, or better yet the re-do list)

It sat in his garage until last year when he tried to fix it up to trade it in. The dealer only wanted to give him $1200, so he gave it to us.
So I get it and it has a check eng. light.
We drove to back from Utah with the light on, it ran fine.

I have it scanned and it had three codes (p1128 and I can't find the sheet on the other two- I know, I know) The diagnostic sheets had possible causes on them and the only thing they all had in common was the O2 sensor and the MAF sensor. I bought a scanner and cleared the codes to see if they reset. As soon as I cleared the codes it idled badly and bogged down when I started off. This only lasted for a minute and I wrote it off as driver error. I drove around for most of the next day when the light came on while on the freeway. I double checked the code and all that was there was the P1128. So I changed the upstream O2 sensor and cleared the code again. Big mistake! Now the car has an extremely bad idle, when I press the gas, it bogs down and backfires, then it will rev up. I can’t drive it enough to reset the light.
I inspected the vacuum lines for cracks or loose fittings and found none. I did find that the wire connection to the MAF was cracked and the wires looked like they weren’t making a good connection. I replaced that and still no dice.

I don’t want to keep throwing parts at this, but the next thing in my sights is the MAF.

Dude you need to scan it and post all the codes present now.More info = better answers..GL KP..

[Mykul]

I'll see if there is anything pending tomorrow. It hasn't thown a light yet.

[simonsi]

Unplug the MAF and see how she runs. With no MAF the ECU uses an estimate to arrive at the correct settings but the estimate can be better than a failing MAF...if she runs better then clean/replace the MAF, if no change then the problem may be elsewhere.

[Mykul]

Originally Posted by simonsi

Unplug the MAF and see how she runs. With no MAF the ECU uses an estimate to arrive at the correct settings but the estimate can be better than a failing MAF...if she runs better then clean/replace the MAF, if no change then the problem may be elsewhere.

I did that already and I didn't notice a differance, but I may want to try again after I clear the new pending codes.

[Mykul]

OK the new list of pending codes.

P0102- Mass Air Flow Circuit Low Input

P0112- Intake Air Temperature Sensor Low Input

P0300- Random Misfire Detected
P0301- Cylinder 1 Misfire
P0303- Cylinder 3 Misfire
P0304- Cylinder 4 Misfire

Should I clear the codes to continue diagnosing?
I think the low input codes were because I ran the engine with the MAF disconnected.

[Smileybug]

Have you changed the spark plugs and wires? That could explain the misfires.

[Mykul]

Because it runs fine with the engine light on, I think the misfires are a symptom of another problem.

[Smileybug]

But have you changed them at all? Could still be an issue.

[Mykul]

No I haven't.

[The Cheat]

here we go...

car wrecked a few years ago, sitting since.

bad gas can ruin plugs and injectors.

change the plugs/wires, and run a can of seafoam through the
tank, intake, and vacuum system.

also, the maf is in fact bad if it's recieving a low input.

but deifinitely at minimum do the plugs and wires. gotta isolate the easy stuff first.

[Canadianbugin]

Originally Posted by The Cheat

here we go...

car wrecked a few years ago, sitting since.

bad gas can ruin plugs and injectors.

change the plugs/wires, and run a can of seafoam through the
tank, intake, and vacuum system.

also, the maf is in fact bad if it's recieving a low input.

but deifinitely at minimum do the plugs and wires. gotta isolate the easy stuff first.

DITTO + Put some fresh fuel in it as the fuel that's in there is BAD.... Might also want use some fuel stabilizer in there.. Do this stuff and clear your CELS and try starting it and scan for codes and repost and let us know...GL..

[Mykul]

I've gone through three tanks of fuel already. And her dad has been driving it for the last 6 months.

I'll play with it more next weekend when I can buy parts.

[Canadianbugin]

Originally Posted by Mykul

I've gone through three tanks of fuel already. And her dad has been driving it for the last 6 months.

I'll play with it more next weekend when I can buy parts.

O K keep us posted...

[Mykul]

Changed the MAF, no light, no peding codes, it's a joy to drive!


The wife took it back.


So I bought some high ratio rockers, a quick shifter and a set of gauges for my aircooled Beetle.

[Canadianbugin]

Originally Posted by Mykul

Changed the MAF, no light, no peding codes, it's a joy to drive!


The wife took it back.


So I bought some high ratio rockers, a quick shifter and a set of gauges for my aircooled Beetle.

There ya go....And ya still got parts for your car...cool X2...