Bad MAF Right ?

[1BADDAM]

Car sputters going down the road, even at slow cruise , light load. Idles like krap. Did the tap test, didn't change idle, no codes either. Briefly saw MAF readings goto 250's just cruising, and on an idle rev. to around 3k.

CC great
02's just hang at .390 to .410 idle and cruise
BLM stayes at 128

Coil pack, plugs, and wires have less that 1k miles on them

Just want to be sure before I plunk down the $$ on a Translator & LT1 MAF.

TIA

 

[Danster]

Try unplugging the MAF during idle and see if idle improves before you rule out the MAF.

On the other hand, I have the Trans + with an LT1 and I just purchased the extender chip. Man, my car is running awesome!


My .02 cents.


Dannyo

 

[are_one]

Check ECM connections. I had similar symtoms that didn't change when I swapped MAFs. Here the ECM pins were corroded which gave turbolink and the ECM all sorts of crazy readings.

 

[ijames]

You say "CC's great". Do you mean O2 cross counts? Cruising at constant speed at 50-70 mph you should see the O2's bouncing between 200 and 750 mV at least, usually going lower and higher, with about 20-40 cross counts per second. Sounds like your ecm is staying in open loop since the O2's really aren't moving and the BLM never changes. You may have some wiring problems, either in the main harness, harness-to-ecm connector, or maybe you just need to reseat your chip in the ecm. Is the check engine light staying on?

 

[1BADDAM]

02 cross counts cycle 0 thru 255 in about 3-5 frames ( have Scanmaster ). No check engine light or any codes.

I checked the ecm to wiring harness, nothing was loose but I'll check again, I'll check the chip too.

When I say cruise, 25-35 mph tops just driving around the neighborhood. On level ground its fine, start to pull an incline and it will sputter or by giving it heavy thottle.

All info from Scanmaster is normal, except

02 mV stay around .390 - .410
BLM stays at 128
Int stays at 128
AF will shoot to 250's, caught it doing it in a few frames right before it sputters, would stay around 15-30 range then shoot up.

Thanks for all the help so far. Any other places to check would be greatly appreciated.

Car has 77k on it, original MAF, so might just get the Translator and 3" LT1, bound to go sometime soon.

 

[1BADDAM]

Drove 140 miles round trip to pick up a buddies MAF, put it in, sputter is gone.

Also why BL and 02 were steady is some moron ( name on top of sig. ) left the 02 sensor wire disconnected. Had a 92 Thrasher in so it wouldn't throw a code 13.

Still don't know why I had CC readings on the Scanmaster with the 02 disconnected

Thanks the help everyone.

 

[Danster]

The Thrasher 92 chip is open idle chip and does not use the 02 sensor. You could leave it unplugged and not get a code with the chip.

Not sure about the CC readings.

Being the MAF turned out to be the culprit, I would suggest investing in the translator plus with the extender chip. Get an LT1 or LS1 MAF. I've read the LS1 is the best, less sensitive to air turbulence.

I'm using an LT1 and I'm happy with it. Not sure how much more improvement it will be if I changed it to an LS1? May try that sometime to just to see if there's any improvement.

Good luck with your decision!

Dannyo

 

[Buick Mark]

My car had similar symptoms for a couple seasons, then steadily got worse. I tried the tap test, didnt do anything, no codes either, then It started stalling after cold starts this past summer, them boom, the car started running like crap, it was only then that the MAF finally coded. It seems it has to be a hard failure for it to code, but all the while, the drivability gradually goes to crap Mark