Houpty

I have a 1986 coupe gt with CIS-E. The gas was bad from sitting and I am trying to get the car running again. I am getting fuel to the fuel distributor and it will come out the cold start line and the lines to the fuel pressure regulator. I get not fuel coming out of the fuel distributor into the injector lines. Also no fuel comes out of the return line from the fuel pressure regulator if that matters or is a seperate problem. The Plunger moves fine and resisted is felt when it is pressurized.

https://forums.audiworld.com/v8/msgs/66322.phtml

I read the above write up. It looks like there is a filter screen on the center cylinder. Could that be clogged and maybe unclogged with carb cleaner. Could the center cylinder have twisted and be blocked because of misalignment.

I think I may have a problem with the injectors also but I can't get the fuel there. Thanks in advance for the help

David Costello

Houpty

Un my fuel dist. I need a 3.5 mm allen wrench because the 4 and 3mm did not work. Do they make these

MiB@100-2.3NF-91

<center><img src="http://pictureposter.audiworld.com/54799/non-return.jpg"></center><p>I had no fuel going from distributor into the injector lines (except cold start valve) then I had bad check valve. Starter was rotating, spark is good - no start. Also changed distributor from running car - same story.

Check valve wasn't holding pressure, I guess.
#43 on the picture, valve sits on fuel pump.

LarryF_in_Ca

Hey Houpty,
Sorry to hear about your fuel related problems. To begin if possible rent buy or steal a CIS fuel pressure gauge. This will check two critical fuel requirements, system and control pressure. System pressure is the pressure that is started by the fuel pump, but controlled by the fuel pressure regulator. Some Audi's have the FPR inside the Fuel Dizzy while some are external.
Anyway if you are getting good system pressure, remember to check the fuel check valve in the tank, then you will need to move on to the next step in solving your problem.
You mentioned that there is fuel coming from the COLD Start Valve and to the Warm Up Regulator (AKA Control Pressure Regulator), but realize that these two components are not controlled by the Fuel Dizzy.
The next thing to check is the output of the Fuel Dizzy. If you did not take it apart then the slits that the gas flows through will be dead on. Realize that these slits are super thin and any sort of gunk will clog up the slits.
What I did is take all my injectors out and placed them in a old Trash can. I turned on the pump by placing a fuse in the relay and I manually lifted up my Air-Meter Flap. After pumping the Flap a few times, my injectors started to spray gas, and you can even hear them as they have a pretty cool HUMMING sound

If you do not get any fuel out of the injectors, then remove them from the lines and see if the lines are clogged. It is sort of a process of elimination. Remember (Good Lines, no fuel from Injectors are caused by two things, low pressure, or clogged Injectors.)

If you can get your Fuel Injectors to spray, then the last thing would be to make sure that your System pressure is higher then your Control Pressure.

Remember that the fuel dizzy has two halves and the bottom chamber is where system pressure is maintained. The top halve is the control pressure chamber. Realize that the pressure from the WUR will make the plunger harder to lift, and it is this property that helps with Cold Starting and warm running.

Finally after I got my car running decent, I still had a long crank time, I added some FUEL SYSTEM CLEANER and this really helped. Any FUEL SYSTEM CLEANER will work cause they all have the same main chemical.

I think that the FUEL SYSTEM CLEANER helps lubricate the system and help keep the seals in the system working. This might help with the GUNK in the FUEL DIZZY fuel slits if this is your problem.

Let me know if my ramblings have helped you.

BUT PLEASE TAKE PRECAUTION WHEN WORKING WITH GAS !!! (THIS IS MOST IMPORTANT)

Later,
LarryF_in_CA

Houpty

If I crack a bolt on a line and let the pressure be released, I can get the injector to fire when the line is closed and the fuel pressure begins to build up but then the injector will stop. I have also gotten some fuel to come out of the return line. Pumping the airflow meter has no effect.

Does this make any sense to you? I took the fuel distributor apart and have put it back together. Is there something wrong with this? My fuel pump check valve is fine and my fuel pump should be fine though it is for an older model car.

I will keep you updated on anything else I find.

I don't believe this car has a warm up regulator. The fuel pressure regulator is external to the fuel distributor.

David Costello
1986 Coupe GT 5 cylinder CIS-E

LarryF_in_Ca

David,
The injectors are openned by pressure. If you do not have the proper pressure the injectors will not spray.

There are two must have books that tell and illustrate CIS fuel systems. One is called "How To Tune &amp; Modify BOSCH Fuel Injection", by Ben Watson (ISBN 0-87938-570-7) and the other is "How to Understand, Service and Modify BOSCH Fuel Injection &amp; Engine Management, by Charles O. Probst, SAE (ISBN 0-8376-0300-5)

These books are a must have if you own a CIS equiped car, like Audis and Porsches.

The injectors need about 3.0 Bar (45psi) to open and spray fuel.

You need to test the pressure of the system. If the supply lines are clogged, even a brand new fuel pump will not give you the pressure needed to open up the injectors.

I would also begin by seeing if all the fuel injector ports on the Fuel Dizzy let out fuel. If you look down the ports there is a small cone screen, this might be clogged.

I you are getting fuel from each port, then you know that you put the Fuel Dizzy back together correctly.

I'm sort of lost, when you lift on the airmeter FLAP you should see gas come out of the outbound ports. If this is fine, then connect the lines without the injectors, make sure that the lines are spewing fuel, and finally make sure that the injectors are spraying.

You have to troubleshoot the system piece by piece.

With all this said, even if you get fuel out of the Fuel Dizzy ports, and the lines, there might NOT be enough pressure to open up the injectors.

This is why it is imperative that you check the pressure.

And yes you are right, the car does not have a WUR, but it does have an Electronic Hydrolic Actator, the large square part of the Fuel Dizzy. This Actuator controls the fuel-mixture.

This Actuator is controlled by three sensors, the coolant temp sensor when cold, the airflow sensor at all times, the Lambda (Oxygen Sensor) when warm, and the wide-open throttle switch. All these sensors play a role in controlling this actuator.

This is all the info I have now, but I think starting with the basics, like fuel pressure, and physical conditions of the fuel lines, o-rings and any other valve or component is necessary.

One last bit, you did replace the FUEL FILTER, right ??

LarryF_in_Ca

Houpty

It seems that once the fuel distributor is fully pressurized it cuts off the fuel to the injectors. With no pressure I can turn on the fuel pump and the injectors will fire for a couple of seconds. I don't think the injectors should be firing anyway becasue the air meter is not even lifted, so this might not indicate anything at all or it migh mean the fuel dizzy is not working correctly.

I have a fuel pump for an older VW or something on there so I need to check if the fuel pump makes the right pressurebut I would guess it does. I ruined 2 other fuel pumps because I used paint thinner to try and clean the bad gas out of the system. The fuel dizzy did not work then either.

Dave