bad MAF = crazy AF numbers?

[JonnyBoost]

i think my MAF is bad, but the the tap test does nothing

i guess my question is if i have a bad MAF will my scanmaster AF numbers be all over the place? because they seem normal to me

is there anyother way to determine if the maf is bad?

 

[don86T]

While crusing along at an even speed the numbers should level off. If they are all over the place it is likely a bad MAF. The car will run terrible while crusing. But it may idle ok.

Don

 

[JonnyBoost]

okay just got back from a little ride...still showing code 34. the car struggled to idle while cold then idled good when warm. all through ride car stumbled when getting on the gas. i made 2 runs one with the MAF plugged in and one with it undone. felt the same both ways. how do my numbers look...anything jump at you??

here are my scanmaster readings after the run, any imput would be apreciated!


@warm - idle MAF unplugged

AF - 06
L8 - 45
INT - 124
BL - 105
CLT - 195
ATS - 74
R - 750
TPS - .44
IAC - 16

@Idle MAF plugged in

AF - 06
L8 - 46
INT - 122-131
BL - 105
CLT - 193
ATS - 100
R - 750
TPS - .44
IAC - 21

 

[pacecarta]

since when was a blm of 105 normal ,
thats very low , 128 is the ideal #, +/- 10

youve got a lot of fuel correcting going on (pulling out fuel)
whats your fuel pressure?
whose chip / injectors?

im guessing with the high temp and low idle its a stock chip\


how old is the o2 sender , if its not reporting back correct values (as in biased high ) the ecm will compensate for that and pull out fuel

what is your fuel pressure?
if its a stock chip anything above 37lbs (line off ) could cause a rich condition and the ecm will respond with trying to pull fuel (low BLM)

 

[NJTurbo]

Originally posted by pacecarta
since when was a blm of 105 normal ,
thats very low , 128 is the ideal #, +/- 10

youve got a lot of fuel correcting going on (pulling out fuel)
whats your fuel pressure?
whose chip / injectors?

im guessing with the high temp and low idle its a stock chip

I was asking the same thing, as you posted

What chip is in this car. I had a bad MAF and the numbers seldom jumped, but idle sucked and now and then it would stumble. If you are going to change it, throw it way and go with the LS1 or LT1 and get a decent chip. The stock chip is not worth a dam.

BLM'S should be 118-138

 

[pacecarta]

you did get a code 34 so something must be up there
did you clear the codes , if you unplug the maf and start the car you will have a code 34
clear the code by unplugging the ecm connector at the battery (orange wire) which will also reset all the blms cells to 128 , and see what shows up and where the blms go


does your maf readings rise while acceletrating ,
do you have one to swap in there to see, thats the easiest way to check them .

btw the grounds for that are in a bad spot on the back of the passenger head and its possible that connection is loose (the O2 ground to the ecm is there as well )

 

[NJTurbo]

Code 34
1) Faulty air ducting to or from MAF sensor
2) Faulty ECM-to-MAF connections
3) Poor routing of MAF harness (i.e. near coil packs)
4) Mis-adjusted TPS sensor
5) Defective MAF sensor
6) Defective ECM

 

[JonnyBoost]

im running stock chip and stock injectors the gauge reads about 34psi fuel pressure at idle. im looking into a new chip but i want to get it back healthy before i start changing things. ive got a reman. MAF coming tomorrow so i'll swap it in and see if thats the problem.

 

[JonnyBoost]

pacecarta

the AF numbers do rise while accelerating just the engine usually stumbles before i can really get a chance to accelerate.

thanks for the advice on the ground i'll look at them in the morning. i have a strange feeling the code 34 might be from faulty wiring instead of the maf itself

thanks guys

 

[JonnyBoost]

Originally posted by NJTurbo
Code 34
1) Faulty air ducting to or from MAF sensor
2) Faulty ECM-to-MAF connections
3) Poor routing of MAF harness (i.e. near coil packs)
4) Mis-adjusted TPS sensor
5) Defective MAF sensor
6) Defective ECM

I've checked # 1,4

not quite sure how to check for -

a defective ECM ?
faulty ECM - MAF connection?

 

[salvageV6]

Check the power to the Mass Air Flow sensor and the ground.

Should be +12 accross the pink/blk and black/wht wires A + C terminals opn the MAF plug, Key on test.

Check the gray/red wire for continuity between the MAF plug and the ECM plug, Pin B6 at the ECM connector also the same Gray/Red colored wire.

Should be low ohms between the MAF connector and the ECM one.

Both unplugged for this OHMS test.

 

[pacecarta]

ecm check the easiest way involves installing a known good one ,

helps to have freinds or more than one turbo regal


as to the connections

the one i would suspect is the ground the black / white wire at the maf connector (terminal c), you can unplug the connector at the MAF and check it with a voltmeter

the middle connector is the gray/red wire and runs to the ecm at the B6 terminal (there are 4 connectors a-b-c-d and the numbers are on the underside ), the digram shows as yellow at the ecm and i dont know if it is because that would require a splice somewhere in the harness

the pink black is the power and is fused (ecm/ign) at the fuse block and should have 12v with key on

 

[JonnyBoost]

thanks so much for the insight guys, i'll check it out in the morning. i swear if this board didnt exist the buick would be permenetly parked in my garage. thanks the leads and for putting up with my general lack of turbo buick knowlege

 

[pacecarta]

to save yourself some time you might want to contact jeremy the cdguy and pickup the 87 buick TR service manual on cd rom (all the regal sections on it)
http://buickman.r00td0wn.net/