924Board.org

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Peculiar isn't it. Looks like there was a hamster living in there at some point back in the 80's.

I thought it was limescale so got some kitchen limescale remover, and poured a little over the edge of my kitchen tap to observe it immediately fizz as it reacted, and removing the limescale easily with a cloth wipe.

I then poured a small amount into the WUR casing to observe absolutely no reaction whatsoever..... Swished it around and still nothing.

Spent a while chiselling the hardened crap all off with a flat bladed screw driver & gunk cleaner spray.

Heater element looks totally fine, and reading correct @ 20 ohms.

Removed small metal disc/ valve diaphragm to find no rust on it, or on the underside of the plate which screws down onto it.
There was however a very slight rust marks on the outer diameter of the valve surface.

Anyway on reassembly i snapped the stud off one the screws which holds the diaphragm down....

overtightened
but technically the..Wur was dead anyway...
Hope a replacement WUR fixes my issues! = ]

regards
Tiny
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*****1981 - 924 - Auto - London, UK******

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

The aformentioned 'crap' looks very much like limescale (calcium carbonate) but is in fact aluminium oxide, which is why your kitchen limescale remover wouldn't touch it.

I find it scrapes off with a kitchen scourer quite well (don't use it for the washing-up afterwards, though

).
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Hi all,
I replaced the WUR with a known good one. Likewise with the AAV.

Checked and replaced an intake boot for a suspect vac leak. No vac leaks, but need to get my hands on a vac gauge to be 100% sure.

Checked and readjusted valve clearances so all are good.

Set timing to haynes spec...bang on 10 BTDC with a timing light.

Got a Gunson Gastester, and set the Air/Fuel mix, to 2.3%
(previously she was smelling and running rich at 8%)

Set idle speed using screw on TB, according to the manual - for my Auto 924 @ 1000 rpm.

She runs smooth as silk when Warm.

BUT... from a cold engine, she starts fine, but will not hold revs up after a minute or so. Runs rough at 300 rpm and then stalls. Once engine is warmend all is fine.
Ozzie suggested unplugging the electric to the AAV during warm up - it makes no difference.

Is it time to check cold/warm fuel pressures with the correct guages?

Also this weekend as an added bonus, I developed the hot start prob.
I Wired up the "hot start fix" to the CSV, but the button only activates the CSV whilst cranking so takes a few goes to get her going, which is annoying.

I'd love to be able to start her up from cold, and drive away like i used to.
What say you, oh wise ones = ]
Tiny
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*****1981 - 924 - Auto - London, UK******

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

Hi, Tiny.

Presumably your engine was nice and warm when you set the CO? (The Haynes manual recommends that you let the cooling fan cut in and out twice before starting the CO test.)

Otherwise, and I hate to say this, it's still looking like your WUR...

But a pressure test will definitely confirm this.
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Hi Mike,
Yes, can confirm that it was driven and fully warm when setting the CO. I took my time and retested / reclibrated gastester....waited/retested and adjusted...etc and i did this process a few times.

I will now test the fuel pressure, once JC whitney gets back to me re: the testing equipment shipping cost to the UK. I sent another chaser email to them today btw. I'll let you know the reply.
thanks
Tiny
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*****1981 - 924 - Auto - London, UK******

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Smoothie · Posted: Wed Oct 10, 2007 1:55 am Post subject:

I'm pretty sure your UK car didn't get the the lambda (o2 sensor) system..?, but does it have EIS? (electronic idle stabilization)(North American 924s from '81-up got it). Both of these (lambda and EIS) can complicate matters and also affect warmup idle.
-But either way, do confirm that the WUR is good first.
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Hi Smoothie,
Yea mine definitely has neither of those components.
Looking forward to testing the WUR
thanks
Tiny
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*****1981 - 924 - Auto - London, UK******

Mike924 · Joined: 12 Aug 2004 Posts: 2601 Location: IoW UK

Buwani 931 · Joined: 31 May 2004 Posts: 308 Location: Napa California

Hard to see if this has the correct adapters but it might be worth a flyer.

http://cgi.ebay.co.uk/CRYPTON-CS1-FUEL-INJECTION-FUEL-PRESSURE-TESTER_W0QQitemZ280161047150QQihZ018QQcategoryZ30921QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting

These show international shipping, also might be worth a phone call.
http://www.toolstoragewarehouse.com/index.asp?PageAction=VIEWPROD&ProdID=5191

I have seen the tool aid brand for under $90 like here but it looks like $1000 minimum for international shipments.
http://www.thetoolwarehouse.net/search/?keywords=33865&storeid=toolswai&GoSearch.x=21&GoSearch.y=15

Shawn
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1980 931
That's thirty minutes away. I'll be there in ten.

924martinirossi · Posted: Sat Oct 13, 2007 5:14 pm Post subject:

I used to rebuild them and calibrate to specs and then sell them for $24.95 to the guys on this board. that was ling ago. I have been into 944s for about 4 years now, but, thinking of getting back into 924's.

Michael

D Hook · Joined: 02 Nov 2002 Posts: 3158 Location: Omaha, NE

A pressure guage is pretty easy to build. I think Haynes has it in there. All the pieces should be readily available at your local hardware store.
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'80 924 n/a SOLD

924martinirossi · Posted: Sun Oct 14, 2007 12:18 am Post subject:

Save yourself some time and buy one from here. This is a well built unit and works! I have one.

http://www.bmpdesign.com/product-exec/product_id/447/category_id/16/search_year/1980/search_model/12

Michael

Roger · Joined: 06 Jan 2003 Posts: 1235 Location: Cordova, TN

You mentioned a hot start problem......check for leaking injectors or leaking cold start valve.
_________________
1981 924 NA

Some people are like Slinkies. Not really good for anything, but you
still can't help but smile when you see one tumble down the stairs.

Tiny · Joined: 10 Apr 2006 Posts: 502 Location: London, UK

Hi Guys, and thanks very much for your input.

JC Whitney won't get back to me so I will try to get the gauges now with BMPdesign. can't wait to get my hands on these beauties.

Re the hot start. I pulled and checked operation of the CSV when i installed the grounding button. The valve openend and shut perfectly.

Funny I must say though, my hot start prob only started when i changed the WUR with a newer used one.

However I believe this newer WUR valve to be permanently shut/clogged.

I have another one coming in the post, too reported to be working fine.

During the hot start cranking, I get no firing at all, but if i just blip the hot start button, the car instantly fires and then dies. I have to do this around 4x for the car to eventually start and idle.

Seems like no fuel, as opposed to leaky injectors.

I also dont have a screw on the bottom of my pressure accumulator -
pt no. 931 110 140 00

thanks
Tiny
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*****1981 - 924 - Auto - London, UK******