Hi Alan,

What is WUR ?

So if the accumulator fails does this mean there is no fuel in the line and by pumping the accelerator fuel gets delivered to the head and will run fine afterwards.
Because once it is running it is strong with no hesitations.

Steve.

The WUR is what controls your fuel pressures - low pressure for rich mixture cold, higher pressure to lean out when hot.
The accumulator holds pressure for 20 mins after shut down, for starts that are neither hot nor cold. Cold starts have the 7th injector for more fuel also. The accumulator does the stuff in between. The WUR should be holding around 1 bar for 20 mins after pumps off. Otherwise, difficult starts.
Alan

Got it,

Warm Up Regulator.

I can see it under the air box circled to the left.
But what is the component to the right. It has a dodgy bit of wiring running toward the back seat direction ?

http://forums.pelicanparts.com/uploa...1550556236.jpg

On the right is the AAR (auxiliary air regulator) - it has a sliding "door" in it which is attached to a heating element . . . when cold, the door is open and allows air to bypass the throttle plate and the idle speed is then raised, and when warm, the door shuts and idle speed goes back to normal.

Thanks Rawknees

May need some attention and explains the higher idle when warm.

http://forums.pelicanparts.com/suppo...s/beerchug.gif

you can pull the inlet hose off the AAR (maybe clear some space first). Then peek down the hole. When cold there should be a bit of a slot in the plate (lets more air thru to go with the extra fuel) . Higher cold idle. When warm the plate should completely block the hole. It runs on a wire /heating element which moves a bimetallic finger which rotates the plate/slot. Welcome to the complicated world of CIS. A marvel in its day, and a rats nest of problems 40 yrs on. But if it is all in spec, works perfectly.
Alan

Yo' Steve, in keeping with Alan's ancient tech observation, this super old school, Bosch K-Jetronic instructional video (complete with VHS stutters :D) is really helpful for getting a basic understanding of the system (despite some differences to the version on your car . . . for example, the air metering assembly is a downdraft unit on the Turbos, not the updraft one in the vid).

<iframe width="693" height="520" src="https://www.youtube.com/embed/a4fJAfXYxWk" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Certainly appears like someone over thunk this CIS system.

It’s going to take me a lot of time to get my head around this stuff Alan.

It is like it has a mind of its own. I just started it after allowing it to sit for an hour and a half and it fired straight up. So I don’t know what the hell is going on.

Steve.

Then it sounds like your accumulator. After 90 mins you will be on 'cold' start. It knows you have zero fuel pressure, so fires more fuel in. You have a choice.
Take a punt and get a new accumulator - about $250 US from pelican +PP. Did one today.
Or do the WUR pressure measurements to confirm what is going wrong.
Alan

That was pretty cool Rawknees,

Looks lik it was recorded on VHS and the tape got chewed at some points.

Good info though, much appreciated.

Cheers Steve.

I think you are correct Alan,

It seems to be an issue more when it is hot. So I am leaning toward replacing the fuel accumulator.

Thanks mate.

Steve.

Per your earlier comment:

So again I peddled the accelerator and got it to fire up.
It is rough when first fired but quickly returns to idle fine.
It feels and sounds kind of like there is no fuel when turning the key and I can definitely hear the pumps run.

Peddling/pumping the accelerator is an old trick for carbureted cars; carbs have an accelerator pump that squirts a small amount of raw gas into the intake when pumping the pedal. Not so with CIS, so I can't see where this action has anything to do with making your car start.

You state that you can hear the pumps running. Are you certain it's the pumps you hear (both of them), or perhaps you're hearing the frequency valve buzzing (freq valve for the Lambda system)? To confirm, put your hand on each fuel pump to "feel" it running if there's any doubt.

Your comment "It is rough when first fired but quickly returns to idle fine" may certainly be a symptom of a bad fuel accumulator as already mentioned. But, I wonder, if perhaps you're having a sporadic fuel pump relay failure whereby you're running on just one pump for awhile. That will reduce fuel delivery at startup and may cause starting or poor initial idle the first few seconds (rough, as you said). I had a similar issue once....would start but idle very low and could not handle any throttle without bogging/coughing for the first half minute of running. The car seemed to run fine though lacking some power. Turned out one of my pump relays was bad. With only one pump running it messes with your WUR trying to establish the correct control pressures. Also, you mentioned something about a high idle at fully warm and have been pointed to the AAR per Mr. Raw Knees direction. Could be you're not getting any power to the AAR so it never heats up.

Here's yet one more thought: If perhaps you have a pump relay issue - and if perhaps it's the rear pump relay - that relay also powers the WUR as well as the AAR heating element. The WUR would still work but would take longer to transition from cold start pressures due to no power to the internal heating element, so you'd run rich longer than normal. With no power to the AAR, the "window" on the disc inside would not close completely when the car is warm and would cause a high idle.

Sorry for the long post; it probably just muddies the water but everything is just a process of elimination. You're definitely not getting sufficient gas at startup and hopefully it is just the fuel accumulator. My car can sit for several months and start right up instantly.

I believe in some documentation this is also called the Throttle Bypass Valve.

The Warm Up Regulator, also called the Control Pressure Regulator, is to the right of the AAR, not visible in your picture. It has a vacuum port on the rear going to an unported nipple on the front (towards the front of the car) of the throttle body, a cloth covered vent line off the top going into your air box, and two fuel lines connected to the fuel distribution head. In addition it has an electrical connector like the one on the AAR.

When you say "It is rough when first fired but quickly returns to idle fine." what exactly does this mean? Is it a low (500-700rpm) rough, lumpy idle for 10 seconds or so, then jumps to the expected idle (either 1,200ish when its cold or 950 or so when its warm)?

Hi Mark,

No apology for the length of post needed. I appreciate all the help and information you can afford me. I really enjoy learning as much as I can about my 930.

The buzzing I hear is from the front of the car and I can hear it when leaning in to turn the key as I never sit in the car to start it. With my head near the top of the windshield the buzzing occurs as soon as I move the key to the start position and runs until I fire it. This always sounded like the fuel pumps being primed.

When hot and started it does have poor idle for half a minute however when driven there is no lack of power it runs strong with no hesitation.

The AAR wiring definitely require some attention.

Thankyou, Steve.

Hi flighthead,

When I first start it the idle speed is more like 950 and when warm more like 1200 so it’s actually the other way round.

Steve.

And just to complicate it more, you could have a couple of crappy injectors that are not shutting off when Off. Dribbling fuel into cylinders, which = rough starts.
But my money would still be on the accumulator. At a guess. It is not an erratic problem, which a bad pump relay would likely be. But as you can see, the whole lot is linked together like a chain. Including your over boost switch. So it is hard to throw darts in a map and hit the spot.
That is why the fuel pressures in the WUR are a good place to start - you can confirm or eliminate a number of things at that point.
Your call, but you would do well to invest in a CIS gauge system. I made mine for about $100.
If you look on line you can see what it needs to consist of. It is an invaluable piece of kit. This 40 yr old beast is going to give you grief again at some point, after dealing to this issue.
Plenty of threads I am sure on how to test this stuff, but we can walk you thru it. fairly simple. Just a bit overwhelming all at once from ground zero.
Regards
Alan

Thanks a heap mate.

Steve.

Check the rear pump running too. If its dead electrically your WUR does not get voltage either so You are too rich maybe even so rich it does not want to start without extra air from gas pedal pumping.

Thanks smurfbus,

This weekend I will get it up on some stands and start with the front fuel pump and then rear pump that’s if I can find them.
Then to the wiring.

Steve.

The front pump is under the bash plate over the front X member. You should hear/feel it.
the rear pump is by the rear LH wheel - you will see the fuel lines. Easy access - put your hand on it. The CIS pressure checks tell you this stuff - system pressure.
Your relays are up the front panel - first and 2nd relay - counting from the firewall bulk head. Pump rear is first one and front pump 2nd one in. If you think one pump is out, try swapping them, F for R.
Regards
Alan