Here I Go: Testing my refreshed 1983 Lambda CIS

[Jameel]

Following Tim's excellent "Dummies" thread I've refreshed my CIS during my rebuild, and now that it's back in the car with the engine, I'm in the thick of it. Posting this in case something doesn't test right, or I need help from the experts. (thank Tim Irwin, Tony from Philly and Dennis "timmy2" for your personal help earlier!)

Here's a general rundown of what I did before it went back on my fully rebuilt motor.

-brand new airbox from Porsche
-new intake boots
-new air meter boot up top (the big alien-head thing)
-new o-rings all around
-new Bosch injectors
-new injector sleeves
-thoroughly cleaned everything I could take apart
-tested 009 WUR for vacuum (held) and resistance (within spec), and made it adjustable.
-tested AAR and AAV for vacuum and with heat, and dec. valve--passed.
-all new vacuum lines
-tested all various hoses and the venturi for leaks (off the air box)--all passed
-tested flow meter switch for continuity--passed
-tested both switches on throttle body-passed
-new gaskets on heads
-bead blasted and thoroughly cleaned all six runners
-new bakelite sleeve fitting and o ring for the cold start injector
-ran new fuel lines from the tank back to the engine bay. Two tunnel lines and the rubber lines to the pump and tank from Len.
-test my TTS. Passed as far as ohms go (pretty sure anyway--memory is a little foggy on this, have to check my notes.)

Here's what I didn't do:

-take apart the fuel distributor. I was too chicken. I did let the piston drop out (very gently into my hand). It was spotlessly clean and smooth, as was the bore. It dropped perfectly as per Jim's method from the Primer. I simply put it back.




-remove any of the hard line. I did undo a couple to get the distributor off the air flow meter, but I didn't touch the rest. They weren't leaking before so I figured why mess with them?

-test the cold start injector. I had no way to hook this up to power, and I'm not entirely sure how to test it now that it's back in the car. My car NEVER had a problem starting, fired off instantly every time even in cold weather, so I'm want to think its fine.

-replace any CIS fuel lines. They are all in good shape, leak free, soft and pliable. My Porsche mechanic had a look last December and said "leave 'em alone"

-replace the fuel pump. Been working fine for the last several thousand miles. I cleaned it up and put it back with a new bracket and rubber mounts. I did buy a new Bosch pump as a backup though.

-test for air leaks after assembling the CIS. New air box, new rubber boots, leak-free hoses, new gaskets on the heads, new injector sleeves and orings: I figured I have a pretty good chance of it being pretty dang tight. I will do the test though if warranted.

-test the frequency valve--I don't know how.

-install a pop off valve. Following Pete Z's advice here. My box came with the spider.

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So today I did some of the "day before" stuff from the Dummies thread, plus tested my injectors for flow as part of the sequence for basic CIS setup after a rebuild.

I hooked up the relay bypass switch up front and put my six injectors in baby bottles. It was a pretty exciting moment when I pressed up on the sensor plate and saw that beautiful go juice spray into those bottles! I was kind of surprised how much effort it took to raise the plate, it wasn't difficult--I just thought it would have just floated up like it did when it was out of the car. Must be fuel pressure resisting this movement. This engine must be sucking some serious air to move that plate.

First I pressed up several times to purge the lines. The fuel was very clear and clean. I guess it paid off to make sure I kept everything taped off for 5 months. Here's the results of that:



I assume since the lines weren't purged, 1,2 and 3 show a little less volume since they are further away from the distributor. That's ok. I wasn't measuring at this point. Just purging the lines. I was pretty happy to see they were pretty close though. (or what I assume is close!)

I emptied the bottles and reconnected them. Here's the results of that:



I held the plate all the way up for about 20 seconds, and got about 100 ml of fuel dispensed. I got excited and forgot to check for spray pattern--will do tomorrow.

Here's the two cylinders with the highest and lowest volume.

#5 had the highest right at 100ml.



#6 had the lowest at what looks to be about 93 ml.



The other four fell between these two.

I know these volumes aren't scientific what with the baby bottles. I think I read that the volumes should be within 20% of each other? I did some digging and couldn't find a real figure on that. Anyone know if I'm good to go?

Also, is 100ml a good volume for 20 seconds at full flow? I think Jim mentions 225ml per minute from the FD to the WUR, but I didn't test that yet. Will do tomorrow.

[boyt911sc]

Jameel,

You are doing a good job and surely will have no problem getting the engine to run on the first or second turn of the ignition switch. Don't worry about the volume per unit time because the flow rate depends how high you raise the plunger. What is critical is the comparative volume of each port to one another. And your delivered volumes were very close to each other.

If you really want to determine how reproducible your data is to do a triplicate run or more and compare the results. The test below I did last week took me 25 runs before getting three (3) consecutive identical test results. See picture below:



It is quite difficult to do the flowrate calibration with the engine installed in the car. Keep up the good work and inspire other people thinking of doing similar project. Thanks for sharing.

Tony

[Jameel]

Nice setup Tony! I'm heading out now to do another run, then test my pressures. If everything checks out, I may be firing this baby up real soon!

Can I ask what changes you did to the FD to get the identical results?

[rwest]

Looking good Jameel. Hope it fires right up.

[Jameel]

Got up early this morning and did some further testing of my CIS.

First off I ran the baby bottle test again and checked spray patterns--all looked good. And the volumes were all the same as before, within 5-10ml of each other. Check.

Then I disconnected the line to the WUR and let it run into a container for exactly 1 minute. 250ml. Check.

Then I hooked up my CIS gauge and started the testing process from the Dummies thread.



Here's my data:

1. Year of engine: 1983
2. US or RoW (Rest of World): US
3. WUR model number: 0 438 140 090 made adjustable
4. Ambient temperature at time of test (in degrees C): 11.4 deg C
5. WUR Resistance (in Ohms): 26.2
6. System Pressure (in bars): 4.8 (Bentley range is 4.5-5.2)
7. Cold Control Pressure (in bars): 3.7 (Bentley chart said it should be between 1.5 and 2.0 at 11.4 degrees, so I loosened my adjustable WUR's nut, knocked the plug (went too far!) then backed it out until the gauge held steady at 1.7 bar
8. Warm Control Pressure (in bars): 3.6 (this is right in the middle of the Bentley stated range)
9. Time delta for Cold -> Warm Control Pressure (in minutes & seconds): 4 min.
10. Residual Pressure @ 5 min (in bars): 1.9
11. Residual Pressure @ 15 min (in bars): 1.7
12. Residual Pressure @ 30 min (in bars): 1.6
13. Residual Pressure @ 60 min (in bars): 1.5

So with all those readings right where they are supposed to be, I'm going to fire up the engine tomorrow.

[timmy2]

Great job testing and confirming all your data.
Can't wait to hear how the first run goes.

[2jmotorsports]

Subscribed. I will repeat this exact process on my 83 in about a year.

[tirwin]

You've done some excellent work. I doubt you will have any problems. Can't wait to hear the results of the first drive!

[Jameel]

Thanks Tim! Appreciate the feedback! Well, it fired up. I'll post the details in my broken head stud thread.

[Jameel]

I'm getting ready to set my air fuel mixture. I'll be using an afr meter. I've read a bunch here, but am still uncertain of exactly what to do. So, some question.

Since I'm running SSI's I've lost my pre-cat test port. My SSI's do have the O2 sensor bung. I know I'm supposed to disconnect the electrical connector for this to do the test. Do I also remove the sensor itself and replace it with the meter's sensor for the test? Or just place the meter's sensor in the tail pipe?

Do I also need a dwell meter to test?

What sort of number should I shoot for on the CO %? I've read mixed opinions. 1% seems to be the consensus.

Should I shoot for 14.7 at idle?

Right now, since I'm at the stage of breaking in the engine and just want to enjoy driving the car, all I want is a solid setting. Later, when I've had a chance to learn more (subject seems quite complex) I'll dial it in to the sweet spot. At least that's the plan.

Im fairly certain it's running lean right now from by baseline setting that I set for the first fire. Below 2500rpm and at 1/3 throttle there's what feels like lean running, very slight bucking (more like what cold carbs feel like) but above that runs great.

[2jmotorsports]

Jameel, did you end up getting it dialed in?