Chevy Astro acceleration problems. *Update* So it still runs like crap

[Silverfc88]

Alright I keep getting a stupid SES light and when I got it scanned I get a code of P0101 (MAF performance).


The problem I am having is it seems like there isn't as much power. Feels like the tranny is slipping while accelerating (Hesitation?) and when it reaches around 50mph I get some pinging/knock sound.


I already replaced the plugs, wires, cap. It still does the same thing as stated above before and after ( Eh, needed plugs/wires anyways). Checked tranny fluid hot, I was half a quart low. Filled it up and still the same thing.

Next I'm going to try a new MAF.


And if it still does it then I guess I will have to check the catalytic converter and fuel pressure. It already has a new fuel filter and I'm sure the fuel pressure is good.




What else can cause the problems I'm having and have the P0101 come online?

[96z28fella]

what year astro van, and im assuming it has the 4.3? check the throttle position sensor..a stuck open TP sensor can miscommincate to the MAF which possiblily set the code off.

[Intercooled T]

If its the 4.3, did you try taking off the hose leading to the MAF and the airbox and cleaning it out? Them things get mighty dirty and a clogged MAF screen can make your idling/acceleration terrible. I had a mice nest in my 4.3 airbox, check yours under the air filter and clean it out, I'm willing to bet its filthy. There is a spray you can buy to clean your MAF screen, try that first after you clean it all out in the ducts

[Dave]

thats not the year with the fuel injection spider is it? those are a bitch to work on

[Silverfc88]

Its a 98 with the 4.3.


Alright today I checked the box and hose leading to and away from the maf and checked for cracks. The box is clean with a new filter. I also tried a brand new maf, but its still acting like its choking/no power.


The idle seems good. It doesn't seem like it has risen any or stumbling.

I haven't checked the TPS or MAP yet.


I'm going to have someone test the backpressure on the exhaust before the cat to see if its plugged.


I'm going back to bed....

[Silverfc88]

Update:


Well I got tired of messing with it so I turned it in to get looked at and let someone else figure it out. They had it the whole day and when they called they couldn't figure out what is wrong with it either. Said they checked MAF, MAP, TPS, fuel pressure, vac, and some other stuff and came up with nothing. Alteast they didn't charge me for it.




So what else is there to check? I guess I'll check the PCM wireing or the wires going to it again, but actually remove the wires for the MAF out of the main harness. Maybe get a different ignition control module. Go to an exhaust shop and check the backpressure on the exhaust.



Man what a pain in the ass.



Anybody know a good driveability GM master tech they could recommend me?

[rocco]

i guess id probally just drop it off at the dealer cant cost too much