CIS Gurus,,,I've had it!
 

OK, this all started with a bad WUR. I tried to have the original adjusted and the throttle arm also adjusted, but ultimately I had a really bad backfire and blew out the airbox (even with the pop-off). One Mech said the screw/locknut is set at he factory and should never be touched, the other Mech didin't waste any time adjusting it. Frack!! I don't know, I'm a carb guy!!

So I have a new WUR, and I dropped the motor and replaced the airbox. I also replaced the runner boots, the runner gaskets, the injector o-rings, the throttle body o-ring and the gasket......I mean I replaced everything. Today I put the motor back in, and I have the same ##@$%^&* problem. The motor starts, runs for a half second or so, then dies. I must have done this (NO BS!) a hundred or a hundred and fifty times, each time adjusting the large idle screw on the left side, and the 3mm adjustment screw in the distributor. No matter what I did, it stayed basically the same. Start then die.

I have great fuel pressure. The injectors sing like a blues concert. I checked a couple, and fuel is flying out of them. I have no idea where to go from here. I have adjusted the two screws from almost all the way tight, to as liberal loose. It always seems to be the same. And I can't find a fuse or relay that supports the WUR and the air regulator. Hard wired???? That can't be.

OK < WHAT ELSE IS WRONG???????> This car ran beautifully before the WUR went out, and it's been downhill from there. Just tell me what to buy and I'll do it. GAAAWWWDDDDDD, I am so frustrated. On the plus side, taking a motor out and putting it back in, ALL BY YOURSELF, really aint that hard.

TIA, Brian :confused: :confused: :confused: :confused: :confused: :confused:

BITZ EFI bitzracing.com

A little trick you may try. Disconnect the wires for the WUR. This slows the warmup of the WUR so the mixture stays richer longer. The WUR will eventually warm up from the enginw heat and have the correct mixture when warm. Good luck.

He said it wont run more than a few seconds . How do you suppose he warms it up ?

Kurt

jstobo

If I tell you that I have been looking for the CIS problem in my Car for the last 18 months . What will you say? And after all it was a misplaced coonnector,that a Porsche Professional Mechanic misplaced. I had the Plate sensor connected to the FV and vice/versa.
Go to this site and you will get there
<http://members.reenlist.com/jimwms/CIS/CIShome.html>

Sometimes the simplest thing will make you crasy
Check the wiring, peel the connectors rubber boots and see if you have the proper wires in the right component.

Be patient

VicSmileWavy

ps. Ah..! your WUR fuse is #18 total Interior lights and Lambda relay if yours is a 911SC 1981/83

If I don't get more help. I'm gonna commit something or other. And I know you don't want me to commit something or other!!

Vic,
Don't think that is the correct URL :)

Vic, I followed your thread day by day. Thanx, but what was wrong with yours is not what's wrong with mine. I wish it was. Then I wouldn't be typing right now, I would be driving!!!

Do you, perchance, have the electrical plugs for the frequency valve and the fuel pump safety switch reversed? I did this by accident after reinstalling motor and had the same symptoms: motor would start and run for about a second then promptly die. Give a look see...

ianc

in the absence of gauges to set up the control pressure, here's what I used to do.

this is all assuming the meter plate is properly adjusted, and you have a new WUR so you shouldn't have pressure issues...

please do this in a well ventilated area...preferrably out doors and take all proper precautions when working with fuel.

remove one injector from it's socket and put a suitable container under it to catch the fuel that is going to spew from it.

now jump the fuel pump relay to run the pump and pressurize the system.

do you observe any fuel dripping from the injector?

if so, how much? you should see a drip every couple of seconds, I know... not exactley scientific, you'll have to get a feel for it.

if there is no fuel, try lifting the metering plate, fuel should spray. release the metering plate. now do you have fuel dripping?

no? ok...turn the mixture adjusting screw to richen the mixture. I believe it's clockwise but it's been a while so someone might chime in here. fuel should begin to drip from the injector as you turn the adjusting screw...go lightly here, a little goes a long way. if you turn far enough it'll begin to spray. get it to where it drips about one drip per scond.

now un jump the fuel pump relay. wait a while. 10 min. then get a helper to re jump the FP relay while you observe the injector. is there any delay in the system pressurizing and fuel dribbling from the injector?

if there is a delay you may have a problem accumlator

if the system quickly pressurizes you should be good to go. pop the injector back in.

at this point you have dumpped a lot of raw fuel into your cylinders. if it were mine I'd disconnect the coil...(not the coil wire from the coil to the dist but the signal wire to the coil...you've sprayed a bunch of fuel around there by now and you don't want any sparks jumping around) and crank the engine over a few times to pump the raw fuel out of the cylinders. then I'd wait a few more minutes to let it evaporate out of the exhaust.

now you should be able to reconnect the coil and fire her up.

you'll still need to fine tune the mixture, but this setup should get it to run.

Westy,

From your original post, this may say it all: "The motor starts, runs for a half second or so, then dies. "

This statement perfectly describes a fuel pump relay failure. The relay has 2 circuits: START and RUN. You engage the starter, the START circuit runs the pump. Engine starts, you release the key, the START circuit disconnects and the RUN circuit engages.

Your description is classic failure of the RUN circuit to become engaged after you release the key from the start position.

The RED fuel pump relay has the two-circuit system. A BLACK standard relay will fit the relay socket, but does NOT have the necessary circuitry. Did you, by chance, replace the RED relay
with a BLACK one just before this problem started?


Now, with THAT being said, it is also possible for the cutout switch on the fuel distributor housing to be defective. That is the switch that senses the position of the sensor arm -- if the sensor arm is at rest (engine not running), then this switch interrupts the RUN circuit to the fuel pump. With air flowing past the sensor plate, it lifts and allows the RUN circuit to power the pump.

During starting, the pump is powered by the START circuit, and this switch is not part of that circuit.

So, if this switch is bad, the engine will do the same thing as a pump relay RUN circuit failure -- because the bad switch is cutting out the RUN circuit.

To test the switch, follow the instructions for bleeding the CIS system. Remove the air filter. Turn the ignition key to the RUN position. The fuel pump should NOT be running. Lift the sensor --does the fuel pump come on? If NO, bad switch.

Brian, you kind of confused me. I've already replaced the relay twice, and it's red, so I know that's good. Interesting on the cutout switch, though. When I removed the motor, it was disconnected. I was told it doesn't need to be connected, and now I can't remember if I plugged it back in or not. If I did, I'll unplug it and see what happens. I wonder if it was unplugged for a reason?

OK, Unplugged the kill switch,,nothing. Happened to look at the box under the seat (Lambda?) and it was unplugged. SCheeet!!! Now I got it running, kind of, but all the mixture adjustments are so far off it's mind boggling. If I remember right, if you push down and idle increases, richen it (turn right), and if you pull up and idle increases, lean it (turn left). Correct???

Westy
Did you get your a/c before you put the motor in ?

Westy,

With the kill switch plugged in, and no air flowing thru the engine, the relay is cutoff. With the switch NOT plugged in, there is no way to cutoff the relay, so the pump runs full-time when the ignition is ON.

At least is is RUNNING -- now you can make the adjustments!!

Good luck

Westy,
If you raise the sensor plate and the revs rise then you can go richer (clockwise). If you lower it and the revs rise then you can go leaner (ccw). If raising and lowering both make the revs fall then you are OK. If you enrichen, you usually have to raise the idle speed (ccw on big screw) and vice versa.

Hoosier, No, and I got tired of having a non-running car in the barn,,,although that's what I still have.

Thanx Paul, but it's still efferd up. I can play with it and get it running, but it won't stay running, even if the idle is at 2200 rpm or more. It eventually stumbles down and dies, maybe from 20 seconds to a minute.

Brian, Thanx. I plugged the switch back in, no difference.

Relays and fuses are good. The car wants to run, there's just something a little off (besides me)!!!

Soooooo, here's my next question. Is there a starting point for the 3mm screw and the big idle screw? I just want this car to run good enough to take it to the shop and put it on an EGA. I've continued futzing with the adjustments, and now it wont start,,,again. When I can get it started, I have to push up on the sensor plate to get gas into the cylinders.

I swear I'm wearing out my starter, and my battery is on the charger. What could possibly cause all this. Everything seems to be working, or has been replaced.

It is my non-expert opinion that I should be able to get this thing somewhat close so I can drive it to the shop. This makes me belive something, a switch, a module, a ????? is in need of replacement.

Here's an idea. Everyone go out to your car, right now, and turn all your screws clockwise until seated, then tell me how many turns it was. :D :D :D :D OK, I know, not a great idea.

this is a great thread. the purple 77 911 i ended up with a few weeks ago is doing EXACTLY the same thing. you get it, turn on the key, the pump runs, the car will start, run for a few seconds and die. i have a visable seeping fuel leak from the fuel dizzy, so i assumed the pressure loss was the cause of the problem. perhaps it is the accumulator and or WUR thats causing the run issue? the last mechanic that knew nothing about pcars took the fuel dizzy apart trying to fix the same thing, so it had the problem before the dizzy was leaking. the car is for sale cheap, but if it doesnt sell i will do "something" with it , i guess. is there a place on the net or the site i can go to that shows me what these wires go to and where the vaccum lines go to???? i am a weber carb guy, i am pretty competent on my Ferrari's. the CIS on the 77 911S is really giving me fits :) . perhaps by fooling around with mine, i can help the thread starter narrow down his issues further!

1600 for the BITZ EFI?? Wow, even if I had that kind of money,,,,wow. Of course then I would have a CIS mural on my barn wall. Just think of the comments when people came over and saw it. AFTER I riddled it with buckshot!!

Westy
I had the same problem awhile back on my 77S and found that my pop off valve had unseated and was causing a leak . I reseated the valve and I've never looked back ( knock on wood )