1983 3.0 CIS question...
 

Bought a used 3.0 motor and the owner can't seem to find the lambda cable from the Jetronic unit to the engine harness. My SSIs will need the oxygen sensor "bung" welded in regardless. I know that if I run the motor w/o the lambda unit I will be lean at start up and rich thereafter. I talked to an engine rebuild expert that said to replace the 83 system with a 78-79 CIS system....but my understanding is that they are designed for the intake port size...and that would not work well. Someone else told me that if I replace the frequency valve and the fuel distributor with one off a euro 3.0 that I would be ok...Help! I want to get the motor back into the car....and this is holding me up

Place a "wanted" ad in the classified section. I would be surprised if you can't find a cable for a few bucks. Until then, run lambda-less.

That said, I wonder why you have to weld a bung in the SSI? Didn't they come with a bung? The correct SSI should have thick flanges and a bung pre-welded.

George

why weld the o2 bung into the exhaust?
 

Original motor that ...blew up ran thin flange SSIs,,,and it was a 2.7.....infact a great 2.7 RIP. I have replaced it with a later 3.0 but will use the SSIs that I have, shorten the exhaust studs and weld in the bung.Questions?

That explains it! Again, look for a used cable in the classifieds here or also try www.partsheaven.com. They will have a cable for sure!

Cheers, George

Speedo,

The Euro 3.0 will, of course, have the larger runners, which will be a mis-match at the intake port on your US 3.0 heads. It will not be an optimum match-up, as it is my understanding that going smaller to larger is not much of a problem, but the reverse (larger to smaller) produces a turbulence that is not good. I don't have any personal experience with this setup, perhaps someone more knowledgeable will speak up here.

Running the US 3.0 fuel distributor, without the Lambda system it was designed to run with, would, IMHO, be even less optimum. As you note, you don't get all the warmup enrichment you would otherwise get. The Frequency valve will get no in put at all, and will be off, corresponding to lean running, not rich. You also will get no acceleration or WOT throttle enrichment. You may be able to richen up the lean running caused by the lack of FV input, but the mixture won't be right except at warm idle, if that's where you set it up.

If you go with the Euro 3.0 FD (less the FV) be sure to change the WUR to the Euro one as well. If you can't find the needed cable for the Lambda, this might be the best compromise.

But, anytime you mix and match these components, the only way you can predict the outcome is if you find someone who may have done it before.

Just my 2c.

Running the 78-79 FD would probably work, but you would have some extra lines you would have to deal with. It wouldn't be plug and play.

Just to be clear, you are missing the harness that runs from the engine compartment to the Lamda "brain", or you are missing the portion of the harness that connects to the O2 sensor?

You can get away without running an O2 sensor, but the rest of the Lamda system needs to be functioning properly. The system will just run open loop, with the Freq valve at a fixed duty cycle.

Tom

Thanks Bob....
 

It appears that I have a carrera cased 3.0 with 77-78 intake runners. I tried to pull off the in take on no 1 and 4 and ran into problems. It looks like a PO might have turned a late case into an early 3.0. I do need a 6 pin CD now...any available?