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View Full Version : finally got a new MAS ... why did I wait so long?!



c55m8o
09-16-2005, 10:32 PM
As Carl has been professing to so many when their car "isn't all that anymore"...

Car had started stalling on start-up; could take 2 to 10 starts to get it to remain running on cold start... then if I'd come to a red light or stop sign within a minute or two after cold start, would stall ... and would buck for much longer then that. Plud general slughishness always... But would take off well enough if I'd go to 1/3 throttle or more. ...odd.

Then I had a really bad day on a trip into NYC a few weeks ago where it stalled a few times on the ride in ; it used to only stall when cold. And the "check engine" light came on on one of them ; and there was one episode where the car just stayed in 2nd and wouldn't upshift ... after about 30 seconds it finally did.

So I called the guy who did my engine swap. He has several MAS controls on hand at all time. Was supposed to meet-up last Saturday but he got stuck in Brooklyn. So I had to wait until today.

He revs the engine, and there's a loud sucking sound, almost a stall, then the engine revs up. He remembers right after the engine swap, how my car would immediately rev up solidly, with no hesitation at all.

He hooks up the Star Diagnosis and sees there's an O2 sensor code, and low and behold a MAS code. But upon going through the Star Diagnosis screens, sees the MAS is "within spec" however. Only 0.93ms adaptation correction I believe it was called (within spec is below 1.34ms or something like that). There are some other screens that all seem within spec. He would normally not change the MAS with readings like this. But there's "another trick" he can do. When he goes to view the air/fuel I'm idling @ 12 Kg/hr (the weight of fuel per hour) ... he says it should be @ 16 Kg/hr. And when he revs the engine it barely rises; never see it above 100Kg/hr. (with a huge delay, almost stall, when reving the engine).

Put the new MAS in, and upon reving the engine, I see values like 658Kg/hr ... woa! He told me to take it for a ride, and on man, why did I wait so long! Immediate response when I touch the peddle (we kept it in RON93). I can not start w/o spinning the tires (was wet). Most noticible was responsiveness off idle, between 1K - 3K rpm. YA! When I'm driving home and traffic slows to almost a stop in the middle lane I'm in, I gun it to change to the right lane ... and the tires =light up=! Best of all -- some of you might have read me bitching about how my car has 325 ft-lb to the wheels @ mid-4Krpm, but about 225 ftl-lb @ redline -- the car pulls noticably stronger up to shifts @ redline. I gotta re-dyno to say for sure, but it seems like I should be seeing 250 ft-lbs @ redline to the rear wheels.

Yes Carl ... I was listening ... I just should have acted sooner! :p

alboogiee
09-16-2005, 10:37 PM
oh if only i could afford a c43->c55 swap...or a new MAS to start would be nice :D

c55m8o
09-16-2005, 10:47 PM
Originally posted by alboogiee
oh if only i could afford a c43->c55 swap...or a new MAS to start would be nice :D new MAS was about 1/36th the cost of my swap... ;)

coolcarlskic43
09-17-2005, 06:18 AM
Originally posted by c55m8o
As Carl has been professing to so many when their car "isn't all that anymore"...

Car had started stalling on start-up; could take 2 to 10 starts to get it to remain running on cold start... then if I'd come to a red light or stop sign within a minute or two after cold start, would stall ... and would buck for much longer then that. Plud general slughishness always... But would take off well enough if I'd go to 1/3 throttle or more. ...odd.

Then I had a really bad day on a trip into NYC a few weeks ago where it stalled a few times on the ride in ; it used to only stall when cold. And the "check engine" light came on on one of them ; and there was one episode where the car just stayed in 2nd and wouldn't upshift ... after about 30 seconds it finally did.

So I called the guy who did my engine swap. He has several MAS controls on hand at all time. Was supposed to meet-up last Saturday but he got stuck in Brooklyn. So I had to wait until today.

He revs the engine, and there's a loud sucking sound, almost a stall, then the engine revs up. He remembers right after the engine swap, how my car would immediately rev up solidly, with no hesitation at all.

He hooks up the Star Diagnosis and sees there's an O2 sensor code, and low and behold a MAS code. But upon going through the Star Diagnosis screens, sees the MAS is "within spec" however. Only 0.93ms adaptation correction I believe it was called (within spec is below 1.34ms or something like that). There are some other screens that all seem within spec. He would normally not change the MAS with readings like this. But there's "another trick" he can do. When he goes to view the air/fuel I'm idling @ 12 Kg/hr (the weight of fuel per hour) ... he says it should be @ 16 Kg/hr. And when he revs the engine it barely rises; never see it above 100Kg/hr. (with a huge delay, almost stall, when reving the engine).

Put the new MAS in, and upon reving the engine, I see values like 658Kg/hr ... woa! He told me to take it for a ride, and on man, why did I wait so long! Immediate response when I touch the peddle (we kept it in RON93). I can not start w/o spinning the tires (was wet). Most noticible was responsiveness off idle, between 1K - 3K rpm. YA! When I'm driving home and traffic slows to almost a stop in the middle lane I'm in, I gun it to change to the right lane ... and the tires =light up=! Best of all -- some of you might have read me bitching about how my car has 325 ft-lb to the wheels @ mid-4Krpm, but about 225 ftl-lb @ redline -- the car pulls noticably stronger up to shifts @ redline. I gotta re-dyno to say for sure, but it seems like I should be seeing 250 ft-lbs @ redline to the rear wheels.

Yes Carl ... I was listening ... I just should have acted sooner! :p ;) I guarantee you the oil from the K&N filter damaged the MAS you had!You applied way too much oil Steve.

c55m8o
09-17-2005, 09:09 AM
Originally posted by coolcarlskic43
;) I guarantee you the oil from the K&N filter damaged the MAS you had!You applied way too much oil Steve. you'll get no argument from me! ... live and learn I guess.

My MAS was questionabe anyway IMO. My car did have a few of those behaviours years ago, and I sprayed Gumout into the intake, which did help a lot; wasn't pristene tho and the car has never felt better then with this new MAS (oh ya, bigger engine helps a tad too ;) ).

...btw, you going for sure on Oct. 8? I'm going to register Jeffrey in the event he goes; he was interested.

coolcarlskic43
09-17-2005, 01:19 PM
Originally posted by c55m8o
you'll get no argument from me! ... live and learn I guess.

My MAS was questionabe anyway IMO. My car did have a few of those behaviours years ago, and I sprayed Gumout into the intake, which did help a lot; wasn't pristene tho and the car has never felt better then with this new MAS (oh ya, bigger engine helps a tad too ;) ).

...btw, you going for sure on Oct. 8? I'm going to register Jeffrey in the event he goes; he was interested. unfortunately I may not be able to go.I'm supposed to go to the Dominican Republic that wknd.

c55m8o
09-17-2005, 02:16 PM
Originally posted by coolcarlskic43
unfortunately I may not be able to go.I'm supposed to go to the Dominican Republic that wknd. Oh crap. That sux. Ya, I read on mbworld ya might be going there but I was hoping plans were tentative @ the time. Well have a good time in any case. I registered Jeff in case he goes.

coolcarlskic43
09-17-2005, 05:45 PM
Originally posted by c55m8o
Oh crap. That sux. Ya, I read on mbworld ya might be going there but I was hoping plans were tentative @ the time. Well have a good time in any case. I registered Jeff in case he goes. Sounds good and I think Curtis and Neil are going as well.Have you heard from Marc Coupey(attorney) Steve?

c55m8o
09-17-2005, 08:26 PM
Originally posted by coolcarlskic43
Sounds good and I think Curtis and Neil are going as well.Have you heard from Marc Coupey(attorney) Steve? Are Curtis and Neil active on boards and registered? Haven't heard from Marc; I guess he hasn't been active on this board lately. ...I have to e-mail him.
-steve

jlomon
09-19-2005, 08:29 AM
I just had the same experience. I just did my MAS on my C280 this weekend as well, along with plugs and new wires and coil-to-plug connectors. The idle is back to that smooth as glass feeling I used to get a long time ago. Most of it was the MAS (I checked the difference before doing the plugs/wires).

The car had developed a real lumpy idle about a week ago, and had been doing the rpm surging at the stop light thing as well. Now it feels like a Benz is supposed to. I can hardly even feel the engine any more.

Jonathan

omeyhomey
04-26-2006, 03:03 PM
are you talking about the MAS airflow sensor or the actual MAS computer?

c55m8o
04-26-2006, 05:44 PM
air flow sensor at the inlet to the intake manifold.