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Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
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I don't know what the cams are, but they do not sound lumpy, and when I steady the plate, it is quite happy to sit there on its own, nice and steady. Which would suggest it is not cam initiated - or else it should start vibrating again, once I take my finger off it. But it stays steady until the throttle position is altered and it has to find idle position again. It seems to set up a 'hunting' mode when trying to find idle position - but at a very fast hunt.
I can't help but think it is a damping issue in the fuel head - but as far as I can deduce that is simply controlled by an orifice - no moving part. So, not much to fail - unless the orifice was blocked?
Alan
Old 11-28-2007, 11:05 AM
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sudo apt-get purge 930
 
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My understanding is that there is a plunger that moves to open or close the orifice.
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Old 11-28-2007, 11:10 AM
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My 'manual' says " A damping orifice in the housing of the metering valve serves the same purpose as the hydraulic damper of a constant depression carburettor, ie it minimises flow plate flutter..."
So, I guess I would be looking in the metering valve area, and possibly for a blocked orifice?
Alan
Old 11-28-2007, 11:58 AM
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Intake tracts of turbo engine are much much longer than for SC and overlapping camshaftshave minimal influence on CIS plate compared to SC. Presumed "pulses" must pass the flapper, go down the tube to turbo, go past spinning blades, go up again, trough the intercooler, intermediate throttle plate and then into the engine. Plus, you have SC cams which are "ordinary" CIS cams, right?

I believe you have self-induced oscillation caused by flapper switch and cycling relays.

With other word: as soon as flapper switch shuts of during the idle, it will cycle the relays and sent low voltage to WUR and idle thingie (and probably send a votage shock to fuelpumps as well), which will induce the oscilation.

I recomend finding a CIS-flapper switch distance where switch aways stays off as soon as flapper lifts. You could even try to bypass the switch for diagnostic reasons. Also, check for possible vakuum leaks. My CIS hunted like crazy until i rebuilt the BOV and tightened every hose under the intercooler.
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Last edited by beepbeep; 11-28-2007 at 12:32 PM..
Old 11-28-2007, 12:30 PM
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Guess I should have looked over the page, would probably have posted this too. HTH:



An outfit called Pacific Injection refurbished mine, it wasn't crazy expensive.
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Old 11-28-2007, 01:10 PM
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I tried Beep Beeps suggestion - self induced oscillation via the switch. I started the engine and waited for it to oscillate. Then I pulled the lead off the safety relay switch. The oscillation continued - even tho the switch was dead. I found I could return the plate to idle if I eased the throttle off. If I just dropped the throttle and let it snap back to idle , the oscillation started every time. And every time I eased it back - no oscillation. This suggests to me a mechanical damping issue in the fuel head rather than a switching issue. The switch cracks open as soon as the plate moves, and is well open at idle setting. It is just that the plate is bouncing around about +/- 1mm, and it sits about 1 mm open at idle.
I am coming to the conclusion something is wrong in the metering valve area. A new voyage of discovery. I did find a good thread on disassembly of a CIS head - although it was actually functioning OK at the time, with no fault symptoms.
One day I'm gonna drive this thing. But not today.
Alan
Old 11-28-2007, 03:03 PM
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Oh, and if anyone wants a page with some extremely good generic CIS reference material and links to non-Porsche K-Jetronic systems, take a gander at this (a Pogo 505 fanboy site. No accounting for taste, but I still think that's kinda weird... :

http://www.aussiefrogs.com/forum/showthread.php?t=48806

Alan, they have a recommendation on that page for a Aussie company that deals with CIS injection for Peugeots.

[Edit:] Found the companies own page. Looks like they train people to work on CIS and make/sell equipment to service CIS parts:

http://www.users.bigpond.com/INTERJECT/KSITEPLN.HTM
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'77 S with '78 930 power and a few other things.

Last edited by spuggy; 11-29-2007 at 04:30 AM.. Reason: Fixed url tag
Old 11-28-2007, 03:47 PM
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Those are good site links Spuggy.
You can flush your injectors backwards apparently. This would have the effect of clearing blocked internal filters. How many injectors fail testing because of that? Quite a few I suspect.
You need a special tool to hold the pintel open. No idea what it looks like, but it would be useful. I actually tried flushing mine backwards, but I'm not sure I was very successful.
I think I will pull my fuel head apart this w/end, failing any further advice suggesting otherwise. If it turns to a bowl of custard, I guess I can always send the bits off to those guys. There is a good pelican thread on how to do this.
Meantime, I will finish my brakes - have my helicoiled bleed nipple back now, and refaced the nipple head. Hopefully will work now - otherwise $'s.
Alan
Old 11-29-2007, 10:05 AM
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