CIS mixture tool

81white911 · 10-23-2008, 01:41 AM

What is the metric size of this CIS allen wrench used to adjust the fuel mixture?

How long of a straight shaft will i need?

Daviboy · Daviboy's Garage

3mm I got this one at local car parts store it has a ball type tip which is ideal for getting into the CIS mix screw, it is about 4" long.

emac · emac's Garage

Davy
That photo just cleared up the hundreds of questions as to where do I place the tool.

Great job.

T77911S · 10-23-2008, 04:02 AM

the long one out of a craftsman set works great.

john walker's workshop · 10-23-2008, 04:16 AM

so how do you get that one pictured into the hole with the engine in the car?

81white911 · 10-23-2008, 04:35 AM

How far down in that hole does it go?

Clockwise or CCW to make it rich?

T77911S · 10-23-2008, 04:59 AM

right to richen (CW). always turn it from lean to rich for final adjustment. if you do not have a way to check CO, here is how i set mine. turn it CW until it surges at idle then back off a tad. blip the throttle and if the RPM's dip down then come back up to idle, it is too rich. turn it CCW about half a turn then back CW a little less than how far you turned it CCW. blip the throttle again. repeat until it no longer dips down when the RPM's come back down. mine is set so it has just a hint of wanting to dip down when i let off the gas. drive it and check again. i later had mine checked and it was dead on 3%.

81white911 · 10-23-2008, 05:05 AM

Thank you for the advice. I can always have it done professionaly later . Just need to get it running.

If i blip the throttle now it just stumbles and backfires

T77911S · 10-23-2008, 05:19 AM

i was sorting out a few little issues too. so i set mine myself and then had it checked after things were right. now i have the confidence to mess with it if i need to and i know i can get it right. now is the time to play around with it and get a feel for setting yourself.

make sure your timing is corrrect and the advance is working along with the vacuum enrichment to the WUR.

OldTee · 10-23-2008, 06:19 AM

I bought a set of allens from Harbor Fright and cut it down some to fit between the sound shield. The end for the rachet is a nice handle to turn the allen.

Paulporsche · 10-23-2008, 06:52 AM

81 White 911,

If it backfires through the intake it is too lean; through the exhaust usually means too rich.

As T77911S mentioned, this can be due simply to the setting, or to other factors, like vac leaks or a poorly performing WUR.

81white911 · 10-23-2008, 07:13 AM

Its definately not the wur that has been cleaned and tested on the car.

Could be vacuum leaks but im running out of possiblities.

I have a Hobbo Freight near here , time to make the trip.

Im curious about the frequency valve not working

dlagerstrom · 10-23-2008, 07:50 AM

You would know if the FV is not working. The description from other board members that got me to understand it was "feels like you are dragging an anchor" and it certainly is true! It runs, but when you step on the gas it doesn't run much faster.

You can feel the FV 'buzzing' when at idle if it is working.

john walker's workshop · 10-23-2008, 08:00 AM

Quote:

Originally Posted by dlagerstrom

You would know if the FV is not working. The description from other board members that got me to understand it was "feels like you are dragging an anchor" and it certainly is true! It runs, but when you step on the gas it doesn't run much faster.

You can feel the FV 'buzzing' when at idle if it is working.

to check the FV function, remove the interior light fuse when the engine is warm and at idle and see if the idle drops off and gets chuggy.

81white911 · 10-23-2008, 08:32 AM

Ok, i got up early 4am and finished work early. Time to find this FV and get buzzed. Where is this thing?

If its not working for some reason. Would it cause the backfire and rough idle?

john walker's workshop · 10-23-2008, 08:38 AM

see my last post.

T77911S · 10-23-2008, 08:47 AM

if your WUR has the vacuum enrichment, which i think it does, it could be that it is not working properly. it acts like an accelerator pump on a carb.
also check timing and make sure the advance is working.

do you have a pop off valve?

what led up to the car running bad? all of a sudden, recent work?

81white911 · 10-23-2008, 10:13 AM

i have a pop off valve, and it pops, so lean condition.

removed the relay under the passenger seat, no change.

reached back to the FV no Buzz.

Replaced the WUR vacuum line, maybe alittle better but still backfires.

replaced the blue vacuum line to the distributor, again maybe alittle better but still backfires.

Im am almost positive the cold start valve does not work. but i let it warm up for at least 20 minutes.

jtfreels · 10-23-2008, 10:36 AM

If the engine is running and you remove the Lambda relay under the passenger seat. The engine should starting running VERY rough, mine just about died.
If you remove it and NO change at all? The I would guess the lambda stuff is not working, so the relay could be bad, does the dome light work? If not check that fuse.

Jay

SCWDP911 · SCWDP911's Garage

Quote:

Originally Posted by Daviboy

3mm I got this one at local car parts store it has a ball type tip which is ideal for getting into the CIS mix screw, it is about 4" long.

Can you use that one with everything in it's normal place?