VW 2.0L 16V Fuel distributer...CIS help

Ok, I'm stumped. Mostly because I just don't understand the concept of this engineering Rube Goldberg oddity. 
 

I've got a 2.0L 16V that has been sitting for a long time and won't start. I think the engine came from a '91 Passat, though it now sits in an '84 GTI.   It had a tankful of bad gas. It's been drained and the lines flushed. 
 

I've  replaced the external fuel pump and the filter. This car has no internal pump. 
 

I've got fuel to the metering head, but not the injectors. I pulled an injector to confirm it wasn't clogged. Even with the injector removed, I don't get even a dribble of fuel. I've lifted the flapper while cranking- nothing.  Seems like there is nothing left to suspect other than the metering head or whatever triggers it. 
 

Lern me the dark secrets of K-jetronic. What triggers it?  What can go wrong with the head?  Any adjustments?  How can I troubleshoot or diagnose?

Thanks!

The CIS fuel distributor is a pressure regulator.  Just like cranking the knob on an air compressor raises pressure, raising the flap increases fuel pressure.  There is no  trigger like an EFI injector has; mass air flow (air literally pushing on the plate) = fuel pressure. The injectors never stop flowing if the plate is raised and the pump is running (Continuous Injection System). More pressure = more flow. You have four little gasoline garden hoses.

If you have nothing at the injectors, and the car has been sitting a long time, you may have corrosion in the metering head or you may be lucky and only have gas gunk clogging things.  You will most likely need to open it up and see what you have.  Fom my understanding, they don't like to sit. I let mine sit a couple years once and it tool several tanks of gas to get back to running okay.

Are you getting fuel flow back into the tank?

I know that this is a transplant from another car, but on my GTI there were 2 fuel pumps. An in tank pump, low pressure pickup, that would bring the gas to a small swirl pot under the car that contained the high pressure fuel pump. It also had a damper and a fuel filter outside on either side. 

Anyways, I would start by cracking the supply line at the distributor and seeing if there is fuel coming out. If you have fuel crack an injector supply line. 

Opening one of these fuel distributors is not trivial. Lots of springs and valves inside. Once you open it expect a spring on top and below each valve for each injector. They are difficult to put back together and might take a couple tries. 

There is also the plunger in the middle that goes up and down that has a screen and can get clogged. 

Either way these things are a curse. 

Never let a cis car sit.  I have a Volvo at the shop just now that I don't have a lot of hope for. Find the pump relay and jump the pump so it runs constantly.  Pull the injectors out of the head and aim them into a container to catch the fuel.  Lift the sensor plate wide open and leave it there.  If nothing at all comes, the pump is not creating pressure, or the piston is stuck in the middle of the fuel distributor.  Turn off the pump.  Four screws hold the distributor down.  Turn it over and see if you can pull the piston out without damaging it.  If so, get a can of spray carb cleaner and let it sit in the center hole with the piston out.  If you split the fuel distributor, it will leak forever, although I've heard from my old long dead boss that you can reassemble them submerged in gasoline.  Don't smoke during any of these operations...

K-jet is a lovely driving thing when it's not dirty or out of adjustment.

In reply to Streetwiseguy :

You need to use a special sealer when closing them. I successfully opened and put back together the one in my '87 GTI. It took me several tries and I would never take one apart again. 

There are people that service them. One very knowledgeable guy in the south east, I can find his name if you want, but I expect this is more of a challenge type car were SVreX doesn't want to go spending $600 or so on having it rebuilt. 

This setup on the stock CIS or CIS-E from the 16v? Troubleshooting the two is a little different, the CIS-E will have a single ECU with Motronic on it, and will have an electrical connection on the metering head for the dpr.

In reply to Paul_VR6 (Forum Supporter) :

I'm not sure. How can I tell?

In reply to Slippery (Forum Supporter) :

I cracked the supply line at the distributor- fuel. I removed an injector- no fuel. 

My game plan is to sell this car.  I want to get it running before selling.

I'm not anxious to spend a lot of money on it, but I will spend enough to get it running.  I am not trying to fit in a Challenge budget.

I need my garage back.

Are you sure the fuel pump is running?

VW uses a special relay that senses RPM and turns off the pump if it doesn't detect the engine turning.

Option 1- fix/ rebuild what I've got.

Option 2- replace the head. 
 

Option 3- try swapping in a Volvo CIS I have.

Option 4- pay someone to fix it. 
 

Option 5- sell as-is (and take a big hit on price)

I'd like it gone as quickly as possible. 

Honsch said:

Are you sure the fuel pump is running?

VW uses a special relay that senses RPM and turns off the pump if it doesn't detect the engine turning.

Yep. It's running. 

CIS-E have an aluminum body, CIS have iron, no?

At least the CIS-E on my Quantum was aluminum and the CIS in my GTI ('83) is iron.

And both were gummed up.  The GTI is gummed from sitting while five successive owners replaced everything but the cause of the no-run (the tach was keeping the ignition coil grounded), the Quantum ran okay except for not giving fuel to cylinder 4.

This is definitely going to be aluminum and CIS-E. 

The 91-92 16v GTIs run Motronic, the 87-89 16v did not. I am not sure if the Passat did or not. 

I would try and remove the plunger and clean the filter before dissasembling the distributor. I would not swap one from another car unless its compatible. 

BTW, there was no 1990 16V GTI to the best of my knowledge. The year was skipped. 

The innards of the fuel distributor is plugged.  Pull it and check the inlet screens for gunk.  If that fixes it, you're one step closer to running.

If that doesn't work, then you'll need to pull it apart and clean it internally.  If you've rebuilt a carb, this won't be too much harder.

https://blog.fcpeuro.com/how-volkswagens-continuous-injection-system-cis-works

https://forums.vwvortex.com/showthread.php?8637722-CIS-fuel-distributor-metering-unit-rebuild

https://ncr-pca.org/index.php/club-activities/technical-sessions/48-cis-fuel-injection-operation

You'll likely want to build or buy (HF apparently has one) a CIS fuel pressure test solution to get the pressures set correctly (once it is running).  You can include the gauge setup with the car when you sell it.

" You can't effectively test fuel pressure without a fuel pressure gauge. Otherwise, troubleshooting is guesswork. Making and using the gauge is very easy. There is no excuse NOT to test your fuel pressure when experiencing problems with your car such as cold starting, hot starting, rough idle, stalling, won't start, etc. The ONLY hang up you may have with making this contraption is finding the METRIC fittings (12MM diameter with 1.5 thread). We get ours from M & W Hydraulics here in Tampa. It may take some creative CIS scrapping to get the fittings together that you need, but you'll get it together! I'm sure. I've got faith in you!

Your fuel gauge will have a 12MM X 1.5 female fitting on one end. This will screw into the fuel distributor at the point where the fuel line that goes off to the control pressure regulator is currently screwed in. You will need the fitting to be attached to a fuel line that will withstand high pressure (80PSI+). The other end of this fuel line is then fitted to a T fitting. Off of one of the fittings on the T, you will screw in a pressure gauge. The remaining fitting on the T will lead off to a gate valve. The gate valve will then lead off with another piece of fuel line that will then have a male 12MM X 1.5 fitting on it that the car's fuel line going to the control pressure regulator will screw onto. "

First caution.  These fuel systems run between 50 and 60psi.  Be careful.  (I have forgotten the exact psi)

And this is assuming you do have fuel getting to the front of the car.  It should have a lift pump in the take to feed the main pump under the car.

Take the air boot off the top of the air valve.

Pull an injector from the intake leaving it connected to the fuel line.  Stick it in a clear jar or bottle.

Bypass the fuel pump relay to make the pump run.

turn on the key to make the pump run

use a magnet on a stick to slowly lift the air valve that was under the boot 

right there at the end of the red line.  

With the fuel pump running when you lift the air valve the injector in the bottle should spray.

If not, disable the fuel pump and carefully remove the injector from the line.  Try it again.

I hope this helps.

In reply to noddaz :

I've done all that. That's how I figured out I have fuel at the meter, but not beyond. 

In reply to noddaz :

A1 chassis cars did not have lift pumps.  Gravity feed only.

There is NOT a pump in the tank. 
 

16v cars came with two fuel pumps, a transfer pump and a main pump in the tank, as already noted.  I know the A1 cars didn't but I'm not sure if you need to retrofit the in tank pump when you put a 16v into an A1 or not.

As far as I know, all factory 2l 16vs came with Motronic but you can get a 16v to run on the older CIS-E that came on the earlier 1.8 16v's.  So you need to figure out which one you have.  Easy way is to look on the ECU, if it's motronic it'll say so, it'll be embossed on the ECU itself.

The fuel tank type dictates the pump. The A1 cars were designed with a tall, narrow tank to ensure that the fuel pickup would never suck air under normal conditions.  The later cars had wide, flat plastic tanks, so they had a lift pump that fed a surge tank that contained the main fuel pump.

That is why they would stop running at half a tank when the lift pump died: the tank would stop gravity-feeding the surge tank, and because the surge tank had its own bleed-off return to the fuel tank, the main fuel pump could not pull fuel through, it would just pull air through the return line instead.

I am 95% certain that 16v Sciroccos had a single fuel pump, as well.

I have a '88 16V Scirocco and it came with a steel tank and two pumps. And the system runs at 80 psi or at least that's what my fuel pressure gage has always read.   And I have agree when CIS-E is tuned right it is a very good system.  It was for what I was doing with the car, racing it in SCCA's IT class. 

Pete. (l33t FS) said:

In reply to noddaz :

A1 chassis cars did not have lift pumps.  Gravity feed only.

Today I learned.  Thank you.

As far as the fuel distributor goes, find a big clean flat area and take it apart.  What have you got to lose?

As a related note here a guy I work with bought a DeLorean that had sat for many years and would not run.  Fuel distributor was clogged.  He took it apart, cleaned it and put it back together.  Works fine.  The guy is also a 20+ year Acura tech and a talented fabricator.   It can be done.