aaron0991

What would cause the 2.8 to idle back and fourth from 2000 to 1000 rpms. The engine slowly climes to 2000 and drops to 1500 or 1000.

aaron0991

thin maybe ill sea foam the engine ans see what happens

Maverick H1L

iTrader: (8)

What year is the car? If it's got an adjustable TPS, the sensor may be adjusted improperly and the ECM assumes a higher idle.

aaron0991

its an 88, i know that the idle screw is cast so i can not adjust it

Maverick H1L

iTrader: (8)

I'm not talking about the idle speed stop screw, which CAN be adjusted after you remove the plug covering it. I'm talking about the TPS, on the other side, under the idle control motor.

aaron0991

I'll have to look

86ttopbird

The readings on the TPS should be between .49 and .53 volts. If its higher or lower, you need to adjust it.

DeathStarr89

iTrader: (1)

Sounds like the IAC motor to me.. pull it out and clean the plunger and passage with some carb cleaner and a small wire brush, then disconnect the battery for a couple minutes. It should stall out on the first start, after that it'll fire up, idle high then back down slowly. Take it for a drive after that and make sure it's ok.

Maverick H1L

iTrader: (8)

.45V to .65V actually... Mine's dead on at .55VDC.

aaron0991

i took off the airflow sensor and the car ran good no crazy idle and no high rpms do you think i should get a new one.

Maverick H1L

iTrader: (8)

Since the sensor is off, look at the orange film inside to see if it's flat or not. If it's not flat (you can tell by shining a light on it), get a new sensor, as the one you have won't read properly with a bad film.

86ttopbird

Yup if you took off the MAF and it runs better you probably need a new one. Like mav said, if the frequency film inside it looks like the surface of the atlantic ocean(wavy as hell), then its bad.

aaron0991

Ok i was just about to ask that, lol thats a nice way to put it. I took it off and it purred like a kitten. Right at 800 rpm's and amazing throttle response. Just couldnt drive it cause it sputtered and spat. The sensor is pretty wavy i'll try to take some pics of it tonight just to show you how bad it is and then its comming out.

Maverick H1L

iTrader: (8)

There was a seller on eBay selling NEW AC/Delco sensors the last time I looked. Don't get a cheapo parts store one... You could install it one month and have it fail the next (been there, done that, TWICE). I know the replacments at the parts stores MAY have a lifetime warranty, but, do you REALLY want to go through this about every year and a half or so?

:edit: Case in point, here is a pic of my latest failed MAF. Notice how the film looks like a skate ramp and isn't even in the same place on the board as the factory one, and that there is no air funnel. This was a parts store sensor with a lifetime warranty, the SECOND one I had to replace in 2 years after I put it in:

aaron0991

so where would i look on ebay? would i just look for 2.8 maf or third gen maf?

aaron0991

just looked on ebay but i cant find new ones just used part store ones.

Maverick H1L

iTrader: (8)

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWNX%3AIT

If you have a Camaro, you'll need to find a way to knock the elbow off without hurting the sensor. Hurry, there's only 20H left.

aaron0991

shouldnt be a problem i have a firebird

86ttopbird

Holy crap Mav, that is bad! The film on the reman my dad bought a few years ago looks like that. I'm glad i switched to a 165 ECM and the 70mm Ford MAF. I dont have to deal with that crap anymore with the frequency MAF's