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Replcing maf

Posted: Sun Dec 28, 2014 5:44 pm
by gsa60
Hi,
I'm about to replace the maf of one of the 400's. well, it's actually 460 turbo from 91. but being very similar to the 480 (at least the engine it's the same as my 480 turbo) I believe I guys can help.
I bought a maf to replace the old one with the equivalent to bosh number 0280212021. The thing is: On my older original unit I have the resistance between pin 6 and pin 2 to be 560ohm and the same resistance is seen between pin 6 and 1 and 6 and 3 (basically pins 1 2 and 3 are shorted together). I read somewhere here that this is expected.
However on the unit that I bought, after adjusting the resistance between pin 2 and 6 to 560ohm I found that resistance between pin 6and1 is also 560ohm but resistance between pin 6and3 is around 1200. So pin 2 and 1 are shorted as my original is but pin 3 is not. I believe (although not sure ) that the value of 1200ohm was in my old unit between pin 6 and 5.

Can anyone please tell me if this is ok?Is pin 3 ignored?
thanks

Re: Replcing maf

Posted: Sun Jan 04, 2015 2:50 pm
by gsa60
Finally I found some info,

looking at here http://www.freewebs.com/hjkort/480ecus.htm in the "connections" section, it seems that pin 3 is not ignored.
Furthermore it looks like the pin 5 and 3 are not interchangeable.
Too bad...
If anyone has further info, please let me know ;)
Thanks

Re: Replcing maf

Posted: Sun Jan 04, 2015 10:32 pm
by Robou
You would clear up things by telling what number the unit has you want to replace.
Then you bought an equivalent to Bosch xxxx021 you say, Chinese?
And why your interest in this resistance stuff, is it not working?
Pin 3 is supposed to be the output to the Jetronic by the way.

Re: Replcing maf

Posted: Mon Jan 05, 2015 8:58 pm
by gsa60
Hi Robou,
Thanks for the help.
I'm not interested in the resistance it self. My original post is rather confusing, I agree.
The basic point is this:
On the original MAF the pins 1-2-3 are shorted together on the new pin 1 and 2 are shorted together but pin 3 is not.
I only put the resistance values because it looked that pin 3 was switched with pin 5. Although now I'm not so sure.
Because this is not my daily car and it's not parked at my home (and because of the holidays :D), I did not have the chance to refit the MAF yet. Also, I'm not very comfortable at installing the MAF before thoroughly inspecting the connections.
PS: I bought it from a parts dealer from Spain. I'm not sure where he bought it (the maker, I mean).
BR.

Re: Replcing maf

Posted: Mon Jan 05, 2015 10:46 pm
by Robou
The MAFs are originally fabricated in Spain, I am familiar with the seller, suppose he bought a lot from the manufacturer.
I found the site quite confusing, the same object for different prices if I remember well.
Anyway, just try it, you can not damage anything in the Jetronic.
Remember, there is xxxx021 and xxxx007 and they are not interchangeable. That is why "equivalent" worried me. They look the same.

Re: Replcing maf

Posted: Tue Jan 06, 2015 9:52 pm
by gsa60
Hi Robou,
Thanks for your help.
I see now why you were alarmed :) . I got the 021 one.
I'll install it in this or the next week. And give it a go.
BR

Re: Replcing maf

Posted: Mon Jan 12, 2015 1:17 pm
by gsa60
Hi,
Replaced the thing finally.
While the engine was cold, I behaved ok. but then it started to hiccup. After fully warm, it misfired noticeably.
I felt a smell kinda "sweet". Tried readjusting the screw. But did not seem to make effect.
Seems the unit does not work correctly.
Anyway, thanks for your help Robou.

Re: Replcing maf

Posted: Thu Mar 07, 2024 10:00 am
by gsa60
Finally after many years found the issue.
The connector to the maf was dodgy.

I have taken it to multiple garages. Some of them from Volvo.

I found by chance actually.

Re: Replcing maf

Posted: Fri Mar 08, 2024 12:17 pm
by Alan 480
gsa60 wrote:
Thu Mar 07, 2024 10:00 am
Finally after many years found the issue.
The connector to the maf was dodgy.
a 'cheap fix' ? ? ? ?
darned annoying when cant get to the bottom of any intermittent issue tho :-(