It Idles Perfectly! :d :d :d

[Ahl 4]

I noticed a few folk have been talking of AFM refurbishing, so I decided to give it a go myself as my cars been doing the falling and dropping revs thing intermittantly for a while now, idles like s*ite when its cold (misfiring thing), and cuts out occasionally, especially if im manouvering around slowly.

 

Anyway, it idles absolutely perfectly after retracking the wiper inside the AFM onto a fresh track of carbon!

My car has done 105k miles and the track through the carbon was very clear.

 

I used the guide found in one of the other posts:

http://frwilk.com/944dme/afm.htm

The hardest part was levering the lid off the AFM without damaging it and also levering the wiper assembly up without damaging the spring and stuff. I put it back together with silicone sealer around the edges.

 

Its lovely - like driving a new car. It starts from warm or cold and idles absolutely solidly. Its also a lot smoother - the flatspots and surges have gone completely! Im so flipping happy :D

 

I also replaced the thermostat (nice warm car now) and exhaust backbox today. The backbox is an Arvin one that I got for £42 and im amazed how quiet everything is now. I can hear a thousand rattles that I never knew existing before!

 

:D

[Robbie G 3]

Right, I'm doing this tomorrow, along with the SAD!

 

Have you actually tried it on a cold from overnight start and idle test yet? Sounds good though.

[pug309twin40s 1]

hmm. just read the site on your link. will have to have a play with one of my spare AFM's as my 205 is crap at idling at startup and won't idle below 1200rpm

[Nick C 0]

Just printed off the stuff - think i will have a go at this.

 

Nick

[Ben Allen 8]

Looks complicated

 

My mates 1.6 GTi idles crap aswell, guess we'll have to whip the AFM off that and give it a clean first to see if that helps, before ripping it apart and putting it back together again!

[Guest CB-Dave]

it's a piece of piss - even if you move the contacts south (which is meant to be harder!)

 

I did it on a spare AFM and it's moved over fine - just need to test it now (after I've put the new box etc on me gti!)

[mossy 0]

Ive been playing around with the SAD Due to bad idle etc... but I thing I might have a go at the AFM as well now.

When I've finish my so called report regarding the SAD I will Post it.

[Robbie G 3]

Ok, I did this!

 

Yesterday I removed the air flow meter and the supplementary air device from my car and stuck them on the kitchen table. We eyed each other up and down a few times, then I set to work with a set of spanners, some carb cleaner, and some 3-in-1 oil.

 

Firstly I stuck a thin rod down the sad aperture, and wiggled the cheese shaped disc until it moved more freely, then stuck loads of oil and carb cleaner down there. I then loosened and tightened the little nut on the back of the SAD. I have no idea what it is or what this achieved.

 

Then the AFM. I followed the refurb guide. I moved the two runners south of the previous marks, marked in this document as more difficult, but it was very easy. Now the runners are moving along a fresh piece of ceramic resistive material. I also cleaned up inside the AFM, lubricated the flap and hinge bearing, and sprayed the temperature sensor. I then put it all back together with black silicone, looks neat.

 

I then advanced the timing to the point where idle speed was maximum but it didn't pink. I also moved the AFM hex screw until the idle was the steadiest and the CO reading was about 0.5% after a blast.

 

Basically this morning things have changed a hell of a lot. I turned the key, and it turned and fired straight away. Usually at this point it stalls straight away, and it did chug a bit, but it didnt stall, and after 15 seconds the idle shot up to a rock solid 1500rpm. The idle then falls steadily to 1000rpm, and with all electrics on it behaves much better and doesn't even look like stalling at that annoying point between when the SAD closes and the engine isnt quite up to temp. Im extremely pleased.

 

Although I still seek the utopia where it doesnt chug for the first 10 seconds, I suspect that this will require a new SAD and AFM. The car has been transformed in other areas - it revs much more freely and sounds a lot more healthy.

 

Go forth and refurbish your air intake devices!

 

My slow hot starting problem has disappeared.

 

PS thanks ahl

 

PPS how do I stop the initial 10 second chugging?

Edited January 8, 2004 by Robbie G

[pug_ham 240 3 Cars]

Ahl, did you need to (or did you) put the extra wire on that is described on the linked webpage?

 

Nice select all, copy & paste Robbie G

 

Graham.

[Robbie G 3]

Ahl, did you need to (or did you)  put the extra wire on that is described on the linked webpage?

 

Nice select all, copy & paste Robbie G

 

Graham.

That's only pre '84 AFMs isn't it? So I doubt he had to.

 

Thanks! I wanted to post that on here but I had to share my delight on PGAC first since this forum was down. I really should have re-written it completely for this forum, I know, but i cudnt be 4ucked.

Edited January 8, 2004 by Robbie G

[pug_ham 240 3 Cars]

That's only pre '84 AFMs isn't it? So I doubt he had to.

In the late 1980s, BOSCH started using a redundant wire from the connectors bridge to the wiper and the wiper. Probably to reduce noise and contact resistance at the pivot point. On a few that I tested, the voltage drop was unusually high. The red wire, above, simulates the BOSCH installation . The blue ties are to take pressure off of the solder joints. I recommend making this modification if ever you have the black plastic cover off of the AFM

 

It's also talking about the 944 Motronic DME.

 

Did you have to do this Robbie?

 

Graham.

[Robbie G 3]

I think there was a wire there already Graham, but it wasn't blue. I wasn't thinking about it since I had read it wrong obviously! I'm not sure if it's going to make any difference, couldn't be arsed to break out the soldering stuff. It's got me thinking though what would happen with a brand new AFM - i spose it could cure all the problems completely. Would love to know what they do when they refurb AFM at places like GSF and then flog them for £180. Surely more than simply remount the track runners?

 

Still want to find out from Ahl whether or not his idles perfectly from start first start of the day?

[Anthony 1,000]

I picked up a reconditioned AFM from a 309 GTi in the scrappy a couple of days ago that looks like it was recently redone (it was pretty much spotless). I'll plug it into my 1.9 in the next few days and see what difference it makes - although my car has always started fine without throttle assistance on all but the coldest mornings (although it is lumpy for a few seconds until the SAD wakes up).

[TB_205GTI 1]

I used the guide found in one of the other posts:

http://frwilk.com/944dme/afm.htm

LOL I think it was my last post before the forum were taken down

[Justin 9]

I took off my SAD the other day as it was sticking open and the car was idling high all the time.

 

Gave it a good clean with carb cleaner and re-lubed it. Checked it out and it seemed to be working nicely. Fitted it back on the car and it hasn't worked since.

 

Takes a while for the car to warm (have to heel-and-toe in the mornings to prevent it stalling) but the idle is rock steady at 750rpm.

 

Might have another go after reading this though!

 

Justin.

[fiji bob 0]

something to bear in mind is that normal silicone sealent will damage any copper present in the afm when its curing, you really need the electronics grade stuff cant remember what its called though

[KRISKARRERA 2 1 Cars]

On this forum or the sister site we need a complete guide to overhauling stuff. Some might argue we have Haynes manuals for that but Haynes wont tell u about overhauling a bloody AFM will it!

[Ahl 4]

something to bear in mind is that normal silicone sealent will damage any copper present in the afm when its curing, you really need the electronics grade stuff cant remember what its called though

 

The little wire was there on my 1990 AFM.

 

Ive been trying to reply back to this post for last few days, but I think the forum was stopped just after I posted!

Sorry, I was a little over-excited when I posted. Everything is true, except that when left overnight it does chug for about 10 seconds still.

The chugging/misfiring was about twice as worse before I messed with the AFM though, so its not that bad.

 

Its so lovely and smooth to drive now, I love it long time.

[KRISKARRERA 2 1 Cars]

Am I right in saying http://frwilk.com/944dme/afm.htm doesn't apply to the mi16 AFM?

I've just pulled the cover off of a spare Mi16 AFM and the 7mm nut refered to on the site is nowhere to be seen!

[ALEX 98 1 Cars]

I found this web site on the forum too and I'm planning to refurb my AFM at the weekend (if I get time).

It would be Ideal if good web pages like this one and the puma Racing tuning guide were pinned in there own forum on this site. I sure there are many other useful sites that have been mentioned that Ive missed.

Alex

[Guest andy.robins]

so glad you found that useful, I had suggested that it could be the AFM that causes alot of these problems, and the high cost prevents people from replacing them.

 

Andy

[KRISKARRERA 2 1 Cars]

Well it is good but am I the only Mi16 owner to have taken the cover off the AFM?

[Guest CB-Dave]

take some pics kris... howay! lol!

[KRISKARRERA 2 1 Cars]

See this pic here:

There's a nut by that number 7 that is undone when adjusting it.

Now look here at my s*ite webcam pic:Sorry about the quality but if you look carefully that sodding nut certainly isn't there!

Edited January 9, 2004 by KRISKARRERA

[KRISKARRERA 2 1 Cars]

Wouldn't it be cool if the black plastic cover on the AFM was clear plastic!