I installed a new warm up regulator recently and cannot get the shark started. The po had rebuilt the old wur and never re-established the correct control pressure. The car always ran rich and the idle was never constant. My guess is that the co and idle mixture adjustments were way off with the bad wur installed, which is why the car will not run with the new wur installed. Any tips on how to get these adjustments somewhat in the correct ball park so I can get the car started? Please help!!!

 

Scott, while the CIS fuel system on your car is relatively simple, proper setup requires a set of gauges and the workshop manuals to get it properly dialed in - control pressure is especially critical on that system.

Do you have those items?

 

Scott,

Try moving your enrichment adjustment to the mid point by counting the turns between the rich and lean then try to start it. If it still won't start try indexing the adjustments between rich and lean from the mid point. Once it starts, slowly adjust it to lean until the engine starts to miss/stumble then mark that point. Then slowly turn to rich until it misses/stumbles and mark that point. Now move the adjuster to half way between the marks plus about 5 to 10 degree rich. This procedure will provide good driveability but will probably need final adjustment if your area requires testing.

BTW this will only work if the WUR is properly set by the rebuilder.

Dennis

 

I believe the car should start , or at least fire, with gas from the cold start valve. I'd check the basics like the plugs are firing and the fuel pump comes on with the key. Not to say that things aren't messed up. The idle mixture screw is really touchy. If you want to hunt for the right spot try moving in 1/8th turn increments.

Here are some links for CIS:

http://www.students.tut.fi/~hezekiel/bosch.htm
http://www.volvoclub.org.uk/k_jetronic.htm
http://www.cfmstudios.com/928fueldistributor/
http://www.pelicanparts.com/techarti...MFI/TipMFI.htm
http://www.auto-solve.com/mech_inj.htm
http://www.ncr-pca.org/tech/tech-cis.htm
http://www.asashop.org/autoinc/june97/techtips.htm

 

Here's the deal:

I do not have the gauges required, but a shop close by can tune the cis. I just need to get the car started so i can get it to the shop.

Plugs and plug wires are new and car ran (although rich) until new wur was installed. Fuel pump runs. Car will run as long as cold start injector is activated.

I replaced the rebuilt wur with a new wur. Are new wur's pre-set with the correct control pressures? I did not think any adjustments were necessary right out of the box.

I will try to find the mid point between rich and lean by counting the turns and hopefully I'll have some luck getting her fired off. What, if any, co adjustments should be made while doing this?

 

if the car will start with the cold sart injector running then you need to richen the mix turn the fuel adjustment screw CW, although hold a screw driver to an injector then turn the screw CW you will then hear a bzzz and this means there is now fuel getting to the injector but not enough to open the injector, turn more until you hear a shhhhhhh sound appear then turn CCW till that sound just disappears try again, it should run enough for you to get it there, and make sure you plug the hole you use to adjust the mix with or you will have a vacuum leak

 

Lizard,

I'm not sure I understand which fuel adjustment screw you are speaking of. The car does run with the cold start activated, but dies imediatly after cold start deactivated. I've been tweaking the CO and idle mixture for an hour with only moderate success. The car will start but will not run without cold start injector firing.

 

the fuel adjust screw I am refering to is in the fuel dizzy its self,
I am taking this from my CIS knowledge of the 924, and some VW models

there is normally a ball bearing or a screw or a cork or rubber bong plugging the hole which will be between the air meter plate and the actual fuel distributor (piece the fuel lines connect to)

 

basically what would have happened is the old WUR would not have had the correct fuel pressure so he would have moddified the air fuel mix to get it running properly as there WUR seemed to fail in the full pressure mode your car is now trying to start but the mix has been set way to lean so you need to enrichen the mix alot to get it working correctly

the fact that it will start with the cold start injector firing tells me this

 

you will notice in picture out of one of the links by GlenL


there is the idle mixture adjustment screw is what I am refering to, even though it adjusts more than the idle mix

 

Lizard,

I have been adjusting that screw from rich to lean and everywhere in between. I could not get the shark to run without the cold start injector, so I resorted to putting the old wur back on. Guess what -- still will not run.

What could it be -- did something else coincidentally crap out. It ran last night and the only thing I did was replace the WUR this morning. I think its time to take a break for the evening and take out my frustration on a couple of beers.

One question, what would result from the WUR not getting power? Suppose the electrical plug is faulty. Is there a fuse that supplies the WUR?

 

the WUR should be getting a constant +12 volts to it, try the test i wrote up in my first post, listen to the injector with a screw driver and listen to it, it is possible that your wiring back ther isn't 100% but this is how I understand it

there is a constant +12volts to the thermo time switch, this passes through the thermo time switch and comes out the other wire, this then runs to the cold start injector and the other wire on the cold start injector is a constant ground,

as you can see in the power to the WUR is for electrical heating to the bimetallic strip so it can raise the fuel pressure, it should have a constant +12volt (fed from the fuel pump electrics iirc) to 1, and to the other pole a ground,

the other thing you might consider checking is weither or not the Aux air valve is stuck in 1 position, put it in the freezer and see if it opens, if yes good, now heat it up does it close?

 

Hupp
I have also been the WUR ringer. My '79 ran poorly when I bought it so I got the correct gauges and discovered the control pressures were out. At the time I knew there was a long list of unknown problems with the car and I didn't want to sink money into high $ parts until I knew the extent of it. So I adjusted my WUR into spec. The dominant theory is that this is impossible, but actually its pretty easy(although slow). If you look at the drawing on the next post up you will see there is a rod between valve diaphram and the valve spring. What you do is take the thing apart and go to the hardware store and buy some 1/16 inch brass rod. Then you cut a rod just a little longer than the one in there. By adjusting the lenght of the rod you can set you control pressures right where you need them to be. Start out about 0.030 longer than stock and shorten it until you get the pressures you need. If the diapharm is leaking you can get one out of a random WUR at pick-a-part for a few bucks. I
This got my car running pretty well, but I was not satisfied. So I bought a rebuild WUR from one of the big 3. With the rebuilt part the car barely started and would not really run at all. I'm not sure if the rebuilt part was bad or if I just have the rest of the system adjusted to my tweeked part, but I went back to my frankenstein WUR. I did not do pressure tests on the rebuilt part.
If you need a good source for the pressure gauge let me know...I think I got a pretty good deal and could probably dig up where I got it from.

 

Should a new WUR need such adjustments? I was under the impression that a new one is set properly right out of the box.

 

A new WUR should NOT need to be adjusted. The air fuel adjuster is a spring loaded 3 mm allen head bolt in the front of the fuel distributor. If your air box is on correctly, you can adjust it trough an access hole without removing the air box. It takes a 7 or 8" long 3mm allen wrench. If your wrench is too short, remove the air box to access the adjuster. Adjusting requires pushing down with the wrench until the bolt nests in the metering plate lever. Since it is dying after the cold start is shut off, try turning the adjustment to rich (clockwise) one complete turn. If the WUR and the rest of the CIS components are OK, it should start. If it starts, do the final adjust as mentioned earlier. If it doesn't start, the CIS needs tested with gauges.

Dennis