Calling all CIS experts - Page 2

jonbot · 03-24-2008, 01:14 PM

Quote:

Originally Posted by wcc

OK, OK, I got it! GEEEZ!

So if you have an O2 sensor, wait a minute, that's right you don't have one do you? LOL!

Hey, sorry if it appeared we were "jumping down your throat", I think Tony and I just happened to be writing replies at almost the exact same time (look at the time stamps), so it appears we were all over you

I appreciate your input, don't take it the wrong way! Have a good one!

Update: Ordered the replacement injector today, should get itlater this week and will give an update once it's installed.

wcc · 03-24-2008, 01:44 PM

No problem, I thought it was kinda funny actually.

Paulporsche · 02:04 PM

Have you tried leaning the mixture yet? You may want to hold off until you replace that injector.

How did you discover the injector was leaking?

jonbot · 03-25-2008, 02:32 PM

Yeah, I agree, I'm going to wait until I install the replacement before I try leaning out the mixture.

I watched as a local CIS/MFI injection guru tested them for me. Visually, I could see that one of the injectors, when the minimum amount of opening pressure is applied, would leak out in a tiny stream as opposed to how the other ones would oscillate between open and closed at very low pressure.

nbazalar · 04-02-2008, 11:08 PM

Sorry good point I'm new to this and it's fantastic!
Thanks again!

jonbot · 04-03-2008, 07:48 PM

Hey just thought I'd post an update...

I received the replacement injector last week, but as I was installing it I decided to take a look at the other injectors' spray patterns now that they are hooked back up to the fuel distributor. It turns out all the rest of the injectors' spray patterns were lacking in one way or another. Some would dribble, some would spray a straight stream, and others would fan out in a half-circle. It's interesting that on the test-bench, only one showed as being bad, but now that they're hooked back up to the distributor, they all look bad. I ordered a set of new injectors, and will report the results... keeping my fingers crossed...

-Jon

cab83_750 · 04-03-2008, 08:28 PM

Quote:

Originally Posted by jonbot

Hey just thought I'd post an update...

... It turns out all the rest of the injectors' spray patterns were lacking in one way or another. Some would dribble, some would spray a straight stream, and others would fan out in a half-circle. It's interesting that on the test-bench, only one showed as being bad, but now that they're hooked back up to the distributor, they all look bad. I ordered a set of new injectors, and will report the results... keeping my fingers crossed...

-Jon

This is a perfect timing thread. I have an '83 and I do not have any CIS issues. However, I always wondered how long the injectors last. Mine looked original; though, I do use techron to 'clean' them up at least once a quarter.

jonbot · 04-09-2008, 09:13 PM

Well, much to my disappointment, replacing the injectors didn't do a gosh darn thing. The car still "bucks" a little off idle. I really don't know what it can be at this point. It seems that when the car is idling it's running rich, but when i'm cruising along, it's running lean. Any input is appreciated.

jonbot · 04-10-2008, 04:39 PM

Come on, someone's gotta be able to suggest something? Stand on one foot and chant to the CIS gods? Do the cerimonial CIS headache dance? Something? Is this thing on?

wcc · 05:19 PM

Ok, ok, I'll take another shot at this. I 'recall' reading somewhere about a test that could be done, 'I believe', it was the WUR, that you could remove from the car and putting it in the freezer to simulate a cold car and then put it in the oven to simulate a warm engine. Then you put pressure to it warm and cold. I can't remember but it may be worth researching. Please don't flame me this time....

Maybe try cleaning the mixture control unit as well.

Did you do anything with the decel valve?

boyt911sc · boyt911sc's Garage

Jon,

Have you measured your control pressure over time? Check your cold pressure before you start your car. Record the initial reading and start the car. Record the time it takes to get to 25, 30, 35, 40, 45, 50 psi.....until it stabilizes. Keep us posted. Thanks.

Tony

LakeCleElum · 04-10-2008, 07:09 PM

Quote:

Originally Posted by gtihop

Try $5.40 a gallon here is Canada!

Yeah - But it's a bigger gallon!!!!!!!

SC-targa · 04-11-2008, 05:54 AM

Looks to me like your warm up regulator is out of spec.

Regards,

Jerry Kroeger

Paulporsche · 06:27 AM

Jerry's chart points out that thre are 2 curves for 79s, depending on when the car was made. Was your car made before 1 Jan 79, or after? A what temp did you take your cold reading?

Bill,

I think the test you are referring to is for the AAR.

jonbot · 04-11-2008, 07:34 AM

Tony, I'll do that and post the results.

Quote:

Originally Posted by boyt911sc

Jon,

Have you measured your control pressure over time? Check your cold pressure before you start your car. Record the initial reading and start the car. Record the time it takes to get to 25, 30, 35, 40, 45, 50 psi.....until it stabilizes. Keep us posted. Thanks.

Tony

jonbot · 04-11-2008, 07:36 AM

It most certainly does look like the WUR is on the high end of the graph. I think I read somewhere it can be adjusted by knocking a certain part of it in or out?

Quote:

Originally Posted by SC-targa

Looks to me like your warm up regulator is out of spec.

http://forums.pelicanparts.com/uploads12/79+CIS1207922056.jpg

Regards,

Jerry Kroeger

jonbot · 04-11-2008, 07:39 AM

My car has the '045' WUR in it, so it would be the graph on the left, making Jerry's excel spreadsheet correct. The cold readings were taken at about 68 degrees F.

Quote:

Originally Posted by Paulporsche

Jerry's chart points out that thre are 2 curves for 79s, depending on when the car was made. Was your car made before 1 Jan 79, or after? A what temp did you take your cold reading?

Bill,

I think the test you are referring to is for the AAR.

jonbot · 04-11-2008, 07:42 AM

BY mixture control unit do you mean the Air plate mechanism?

The only thing I tried doing with the decel valve was disconnecting it and plugging the line. It didn't help with the "bucking" at all.

I'm thinking the problem is in the WUR or the FD at this point.

Quote:

Originally Posted by wcc

Ok, ok, I'll take another shot at this. I 'recall' reading somewhere about a test that could be done, 'I believe', it was the WUR, that you could remove from the car and putting it in the freezer to simulate a cold car and then put it in the oven to simulate a warm engine. Then you put pressure to it warm and cold. I can't remember but it may be worth researching. Please don't flame me this time....

Maybe try cleaning the mixture control unit as well.

Did you do anything with the decel valve?

Paulporsche · 04-11-2008, 08:12 AM

jonbot,

My response to you just got lost. Search this. You can knock the pin on the top of the WUR to lower the cp and richen the mix, or you can make it easily adjustable both ways by some machining.

The thing is, your cold cp @ 68 should be about 1.95-2.45 bar or about 29-44 PSI. You got 25, which is too low, causing a too rich mixture, but not by much. Your warm @ 48 is also just a little off.

This brings me back to the original suggestion by me and others to try a slight leaning of the mix, say just a 1/16 turn or so. Did you ever try this? It may be all you need.

Paulporsche · 04-11-2008, 08:18 AM

OK I think I finally get what's going on: your ccp is too low+too rich. Your wcp is too high=too lean. There are a couple of ways to vary the relationship between them. One is via a screw found under the brass plug on the WUR bottom. And I think the other is by bending the lever inside the WUR which apparently tends to flatten over time.

Also have you checked the screen in the WUR for any obstructions?