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Setting up Fuel Distributor? Running Fault.

 
Old 07-06-2010, 04:22 PM
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johnb
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Default Setting up Fuel Distributor? Running Fault.

1981 S Manual (UK) K-Jetronic (CIS)

Does anyone have any experience of setting up a K-Jetronic (CIS) Fuel Distributor?

I have had mine apart to clean and was wondering how you set up which spacer washers go with which spring in the metering head? I am fairly sure I have reassembled as it came apart, but just have a niggle in the back of my mind.

Is it just a case of ensuring that the springs with their top hats all sit at exactly the same height above the casting, before you fit and seal the metal 'gasket' and top half?

I am having problems with the running on my car.

Fuel pressure and flow rate are all good, hot and cold control pressures are spot on, CO at idle is 1.8% (with air pump disconnected).

All vacuum connections check out, and I have no air leaks.

Idle is good and smooth, starts easily hot or cold.

BUT:

The car is undrivable, any throttle and I lose 1 or maybe 2 pots, with rough running etc/ Same on load or just revved up off load.

Car has new Beru leads, new NGK plugs, new rotor, distributor cap looks good.

Thoughts would be appreciated.

I have just purchased a set of 8 calibrated pots, my intention is to collect the fuel from each injector at a fixed air plate depression to check that the same quantity fuel is injected from each injector.

Running fault feels like an ignition fault to me, but as I have been fiddling with the injection system, I thought it best to start there.

John
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Old 07-06-2010, 04:51 PM
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Go-carter
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I would also like to find out wether or not the spacers ar important. I managed to open my fuel distributor upside-down so i mixed just about every srping, washer and spring seat. Stil, it runs pretty good, except for a bad ignition system.
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Old 07-06-2010, 08:58 PM
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GlenL
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You can tell if that pressure regulator is set right only with a pressure gauge. And you've checked that.

Each feed in the distributor is the same so now worries mixing parts.

This is a puzzler. Have you watched the air plate as you open the throttle? Maybe that's stuck or is sticky.
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Old 07-06-2010, 09:25 PM
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vze2jshn
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My U.S. '78, 928 CIS spec c/o at idle is 1- 3 +1 if yours is the same you may be running a little lean.
I would do wsm check of ignition--.4 and .6 resistors can cause problems.
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Old 07-07-2010, 03:24 AM
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johnb
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The distributor feeds are only the same if the valve seats in the fuel distributor all operate at the same time. If the spacer washers have been mixed up under the springs and valve seats then the delivery could be all over the place.

I had forgotten about the resistors - I will check those.

I will reset the mixture 'by ear' by turning the mixture each way until I find the 'sweet spot' for the engine.
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Old 07-07-2010, 08:13 AM
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Best to do CO at a shop with a an accurate read out.
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Old 07-07-2010, 01:28 PM
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johnb
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I have one myself! No need to go to have it done.
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Old 07-07-2010, 10:29 PM
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Can you determine if the dropping cyls are always the same? I had an intermittent misfire a couple of times, and since my injectors had been cleaned or were new, I didnt think it was them. I found accidentally that cracking the injector line (not running) released a squirt of gas, and then the misfire went away. My wrench said that was a sign of dirt in the distributor head getting held in an outlet by the pressure, and relieving the pressure allowed it to fall away, and as long as it didnt get back into the outlet it would be ok.
jp 83 EuroS AT 52k
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