Mass Air Flow Sensor "fix" on GM 2.8l V6 engines
ven._polychronakos
air flow sensors (MAF) on GM 2.8l V6 engines, a couple of
persons replied saying that the cure is a fix which causes
the ECM (car's computer) to ignore the sensor's reading and
use the "speed density" to calculate fuel delivery. A new
PROM, I guess, turns off the "Service Engine Soon " light
which otherwise would be constantly ON if MAF is disconnected.
I called the dealer who sold me the car but he claims he
knows nothing about it. I called Chevrolet's customer service
to see if they have a "warranty adjastment" policy on this but
they said that they don't. Does anybody have any details on this
fix? Any references to GM technical notes to dealers or whatever
they call them? Any personal experience, how much did it cost,
etc?
By the way, I don't make much of GM's denial of any knowledge
about this problem. After being told that there isn't any
known policy adjastments for my car's VIN ('88 Celebrity wagon,
2.8l, V6) I asked the person at the other end of the line about
the problem with the paint on GM cars '87 and newer that I had
read in a local paper. She said that this was not an official
GM policy (and that's why it did not turn up in the computer
search, I guess) but they are considering it on an case-by-case
basis!(my translation: when people find out about it and ask).
Thanks in advance, Ven.
PS. I am having my car painted by the dealer, free of charge, next week.
Petru, Tim
Mark Shaw
We have an 88 Celebrity 2.8L and I recall a PROM change a couple of years
ago. It was free, so I didn't take much note of it. Usually these are
done to solve some emissions drift problem. I had heard of this fix to
ignore the MAF since they are fairly prone to wear out in about 30-40K
miles (lost one on an 85 Pontiac Grand Am -- interesting experience in
"limp home" driving). Anyway, our 88 has worked fine and is up to about
80K miles now. I guess I could always go home and try driving it
around the block with the MAF sensor disconnected.
Mark
Michel_Den...@xerox.com
In article <1993Apr30....@bnlux1.bnl.gov>, Ven. Polychronakos writes:
A new
|> PROM, I guess, turns off the "Service Engine Soon " light
|> which otherwise would be constantly ON if MAF is disconnected.
Well that's a funny way of putting it. The new prom doesn't "turn the light
off", it ignores the MAF sensor entirely. Since the MAF values are no longer
being used, they won't cause the light to come on anymore.
|> I called the dealer who sold me the car but he claims he
|> knows nothing about it.
Snort! This is one of the most famous GM problems in recent history. Your
dealer is either a liar or an idiot - or both.
I called Chevrolet's customer service
|> to see if they have a "warranty adjastment" policy on this but
|> they said that they don't. Does anybody have any details on this
|> fix? Any references to GM technical notes to dealers or whatever
|> they call them? Any personal experience, how much did it cost,
|> etc?
Go to your library and get a copy of an article called, "The V6 From Hell", in
the Mar. '92 issue of "Motor" magazine. This contains a complete description
of the 2.8L MAF problems, along with the GM tech. bulletin numbers. The
article claims that GM has issued literally hundreds of bulletins on this
problem over the years. Your dealer should have a complete set of these
bulletins, which you are entitled to look at (it says so right in your owner's
manual). You can also buy them from Helm.
I have an 88 Celebrity wagon with the 2.8L V6 (engine code W). I had the MAF
to speed-density upgrade done last summer. It was free.
Then ma...@wdcwdc.sps.mot.com (Mark Shaw) sez:
"We have an 88 Celebrity 2.8L and I recall a PROM change a couple of
years ago. It was free, so I didn't take much note of it. Usually these are
done to solve some emissions drift problem."
Well, driveability problems actually - mainly stalling and erratic idling.
"I had heard of this fix to ignore the MAF since they are fairly prone
to wear out in about 30-40K miles"
The Motor article says they almost all die by 50K.
"I guess I could always go home and try driving it
around the block with the MAF sensor disconnected."
Nope - the connector also carries the MAT sensor data, which you still need.
- Michel