mafsim maybe???
06 December 2006, 10:06 PM
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mafsim maybe???
a friend of mine has had his car recently mapped by a very reputable mapper!
it's a 2 litre with a gt30 (I know
)
apexi fc
avcr
550's
mafsim (to replace original maf)
etc
car was mapped to 1.2 bar and was running quite well (although lumpy when cold and hot)
but within a few days of mapping the boost slowly dropped off (now about 1bar)
and car slowly running worse!
yesterday the car coughed/spluttered and broke down!
the only tell tale sign is the plugs are extremely sooty (overfueling)
wondering if this was possible faulty mafsim???
cheers guys
(the poor lad has spent thousands and not getting anywhere!)
it's a 2 litre with a gt30 (I know
)apexi fc
avcr
550's
mafsim (to replace original maf)
etc
car was mapped to 1.2 bar and was running quite well (although lumpy when cold and hot)
but within a few days of mapping the boost slowly dropped off (now about 1bar)
and car slowly running worse!
yesterday the car coughed/spluttered and broke down!
the only tell tale sign is the plugs are extremely sooty (overfueling)
wondering if this was possible faulty mafsim???
cheers guys
(the poor lad has spent thousands and not getting anywhere!)
07 December 2006, 08:00 PM
#6
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Also check all the intercooler hoses...Any leaks on the pressure side will cause it to lose boost and run rich............
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08 December 2006, 12:48 PM
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Originally Posted by AndrewC
What MAF voltage do you see in the Commander at ignition on and at idle?
This should tell us whether the MAFSIM is generating rubbish.
Andrew...
This should tell us whether the MAFSIM is generating rubbish.
Andrew...
08 December 2006, 07:22 PM
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Hi
I had a very similar problem and (in my case) it did turn out to be the MAFSIM. Playsatan also experienced this problem. Basically, went through 3 MAFSIM's before finding a 'long-termer' and haven't had any issues since.
The symptoms for me were (on the first fail) massive overfueling which when diagnosed turned out to be the MAFSIM believing it was under load and throwing fuel at the engine. The second fail was more gentle and the car could still be driven provided I didnt try to hit boost. The smell of petrol was still very noticable. The third one put the car off the road again but (thankfully) the last change over did the trick.
In each of the above failures the car worked perfectly for a while after the MAFSIM was changed but failed fairly shortly afterwards. The last MAFSIM has been working since September.
Cheers
I had a very similar problem and (in my case) it did turn out to be the MAFSIM. Playsatan also experienced this problem. Basically, went through 3 MAFSIM's before finding a 'long-termer' and haven't had any issues since.
The symptoms for me were (on the first fail) massive overfueling which when diagnosed turned out to be the MAFSIM believing it was under load and throwing fuel at the engine. The second fail was more gentle and the car could still be driven provided I didnt try to hit boost. The smell of petrol was still very noticable. The third one put the car off the road again but (thankfully) the last change over did the trick.
In each of the above failures the car worked perfectly for a while after the MAFSIM was changed but failed fairly shortly afterwards. The last MAFSIM has been working since September.
Cheers
09 December 2006, 08:59 PM
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Hi people, still trying to cure the program. Managed to get in touch with andy and he suggested It could be the fuel regulator or the o2 sensor.
Turned the reg down but still no better, will try a new o2 sensor tomorrow. Thanks for all your help and suggestions.
Matt
Turned the reg down but still no better, will try a new o2 sensor tomorrow. Thanks for all your help and suggestions.
Matt
10 December 2006, 02:54 PM
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Took the plugs out on thursday, cleaned them up and put them back in this morning. I also fitted a new o2 sensor but the problem is still there!!! I know that the mafsim takes its signal from the avcr pressure sensor so ive also checked the wiring and hose plumbing. This is all ok. With just the ignition on im getting an airflow reading of 540mv on the commander. When I crank the engine over Im getting a reading of anything between 1000mv and a maximum of 5000mv!!!! Is this normal?
11 December 2006, 06:14 PM
#14
As DesR mentioned I had a failure but the symptons were totally different. The first sympton was poor cold idle but it was like this from day one and after a minute or so it was fine but then one day it just failed completely.
I pulled the car out of the garage onto the driveway to do some work on it, can't remember exactly what it was but it was electrical so I disconnected the battery. When I was finished the car would fire up but idle was super lumpy and whenever I touched the throttle the car would die instantly. I checked the airflow reading on the commander and it was only reading about 50mv where it should have been closer to 500 for idle.
I ended up taking the box out and back to my mapper. He plugged it into the laptop and all the setting had been wiped from it, every value was zero. This should not have happened even with the battery disconnected so he loaded my setting onto another box and that did the trick.
I pulled the car out of the garage onto the driveway to do some work on it, can't remember exactly what it was but it was electrical so I disconnected the battery. When I was finished the car would fire up but idle was super lumpy and whenever I touched the throttle the car would die instantly. I checked the airflow reading on the commander and it was only reading about 50mv where it should have been closer to 500 for idle.
I ended up taking the box out and back to my mapper. He plugged it into the laptop and all the setting had been wiped from it, every value was zero. This should not have happened even with the battery disconnected so he loaded my setting onto another box and that did the trick.
11 December 2006, 11:03 PM
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so will Matty D be able to take his mafsim off and send it to Andy f to redo? (will Andy know what it should be set to?)
otherwise he's going to have to trailer his car to Edinburgh again and another map just because of a faulty part???
cheers guys
Mark.
otherwise he's going to have to trailer his car to Edinburgh again and another map just because of a faulty part???
cheers guys
Mark.
12 December 2006, 04:23 PM
#17
Originally Posted by sponners
so will Matty D be able to take his mafsim off and send it to Andy f to redo? (will Andy know what it should be set to?)
otherwise he's going to have to trailer his car to Edinburgh again and another map just because of a faulty part???
.
otherwise he's going to have to trailer his car to Edinburgh again and another map just because of a faulty part???
.
On the sim is a screw fitting holding a plug in place. Just unscrew it, take the sim box and drop it in a jiffy bag. I live less that an hour away from Andy so just took it in person and got the replacement there and then.
I haven't had any problems since.
11 January 2007, 01:08 PM
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Apparently there was an issue with the programming software that could, after some time, corrupt the settings.
The Mafsims are now using a different type of programming code that can't do this anymore.
It was a tricky one to track down as the units would work perfectly when tested on the bench and quite a number of them have been running for years in road and race cars without issue.
Andy
The Mafsims are now using a different type of programming code that can't do this anymore.
It was a tricky one to track down as the units would work perfectly when tested on the bench and quite a number of them have been running for years in road and race cars without issue.
Andy
11 January 2007, 02:40 PM
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Just to add to what Andy has said, I have a test rig on which all MAFSIMs are run for 24 hours before I send them to Andy, this includes power cycling the boxes 100 times.
I have had components burn out during this testing but have never had one corrupt its settings as has happened on a couple of boxes once fitted to a car, not being able to recreate a problem always make it's more difficult to fix.
Hopefully the latest change has resolved the problem once and for all.
Andrew...
I have had components burn out during this testing but have never had one corrupt its settings as has happened on a couple of boxes once fitted to a car, not being able to recreate a problem always make it's more difficult to fix.
Hopefully the latest change has resolved the problem once and for all.
Andrew...
11 January 2007, 08:28 PM
#23
Thanks for the update Andy/Andrew.
Andy, do you know if my box now has the new setting or not? Not a major concern as I'll have to come over for a remap soon as you know.
Out of interest, if it were to go again is there anything you can change on the commander as a "get you home" measure?
Andy, do you know if my box now has the new setting or not? Not a major concern as I'll have to come over for a remap soon as you know.
Out of interest, if it were to go again is there anything you can change on the commander as a "get you home" measure?
11 January 2007, 11:16 PM
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Any units with issues have shown up in the first few weeks so I'm sure yours is fine Colin.
Without refitting a maf, there is not much you can do if it fails short of replacing it.
Only a few units from a specific period have caused issues, all the units before and after have been 100% reliable.
Andy
Without refitting a maf, there is not much you can do if it fails short of replacing it.
Only a few units from a specific period have caused issues, all the units before and after have been 100% reliable.
Andy
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