Hi All, if someone could share the 328 workshop manual section on fuel injection covering the Bosch K Jetronic Lambda system with me I would greatly appreciate it as I have a problem I need to diagnose and fix. Thanks, Ray
Ferrari published a 328 with K-jet manual someone here has hard copy but there is no scan yet and good luck getting it. Someday I will buy a hard copy scan it and share it with everybody. The next best thing is the Mondial QV workshop manual which has a section on the K-jet and the Official Bosch K-jet tech notes, both are available on the net, I can't find the links at the momments. Also there are tons of K-jet info on forums and the net just do a search on your favorite components such as AAV, FV, WUR, cold air injector, hot start, cold start.... Have fun.
Hi Ken, thanks very much, I have a Mondial shop manual as that was all I could find when I bought the car, but unfortunately it is only for the pre-Lambda cars. I have used the posts here extensively (many by you) - thanks to all for the great help. My 84 308 QV starts fine, but was running rough til warm until a month ago (that was tolerable) - now it has no power, accelerates barely, and occasionally backfires thru the air intake. Cannot find any vacuum leaks. Fuel pump flow rate is in spec. But, after checking all my FI components, I have yet to find anything wrong that is reasonably obvious (like the WUR is in spec, I did get the 328 Bosch Lambda WUR data from Larry Fletcher). Aux air device works; primary pressure in system just a tad low (4.9 bar). Cold start ok. The Freq Valve is working; I want to check the duty cycle under various conditions so I need specs on that (found some for VW Rabbit on web, but doubt the same values pertain). Checked the ignition, it seems to be ok tho' I have yet to figure out how to look at timing as I can't find a convenient place to see the flywheel. Beefed up grounds to Digiplex units; cannot see any "lightshow" on wires or plug connectors (replaced plugs 6 mo's ago). Anyone's thoughts will be welcome.... Thanks! Ray
Ray -- go here: http://ferrari.stevejenkins.com/books and open, then save, the "328 Tech Specs, Publications List, Recall..." .pdf file. In the "Service Bulletin" section under "Electrical" there is Service Bulletin No. 80-29 (starting on page 134 of 147) that gives the various electrical measurements to make to confirm/deny if the Lambda stuff is working OK.
HI Steve, thank you very much for the post...that checklist will be a BIG help. I had actually checked a few items already based on my "educated guesses" but having the voltage specs is invaluable. Question: from the symptoms I described above, and based on the tests I've done and found no problem so far, how likely is a fuel distributor to be the problem (that is one item I cannot check easily). When I manually give the warm engine throttle, it does not rev freely unless I push down on the air sensor plate, which is why I suspect the distributor may be at fault. When off, the plate does move freely as described in the Mondail shop manual.... And, do you know a way to really test the spark plug extenders? Best regards, Ray
If pressing down the metering plate a little (i.e., adding more fuel to all cylinders) makes everything run smooth and well, that would be a sign that the FD is OKish IMO. The usual trouble with a FD is when it isn't delivering an equal amount of fuel to each cylinder. You say that you've measured the warm control pressure, and it is still OK, but the tolerance is fairly large, so, if it's changed since the last mixture tweak was done, the mixture screw still could need retweaking. Is the warm idle with the O2 sensor unplugged still good? It's almost unfortunate that your FV seems to be working as the FV not working would cause your symptom. It is possible that, although the FV is physically "buzzing", it really isn't doing anything (hydraulically) to the lower chamber pressure of the FD. I don't know if you can get a pressure gauge hooked up to the lower (or upper) chambers with the FD mounted in the car and the engine running, but, if you can, you could unplug the FV (i.e., force it to 0% duty cycle) and see if the lower (or upper) chamber pressure rises (as it should with a 0% duty cycle). In fact, with the engine at warm idle, if you just unplug the (buzzing) FV, and nothing changes with the engine running that would be a bad sign for something inside the FV; and conversely, if unplugging the (buzzing) FV changes the engine operation at warm idle that would be a good sign for the FV. Just some thoughts... Don't know of anything special beyond measuring the resistance and looking for cracks/pinholes in the insulating material.
Steve, thank you SO much for these good ideas; i shall follow up and reply. I esp. like the thought of trying to measure FD pressures relative to FV operation; will try that in next day or too if i can rig up the "plumbing"....you know how tough that can be with the metric fittings. Tonite will measure some of the electrical checks in your previous post... Best regards. Ray
For anyone who is serious about this task and assuming you intend to share a pdf file, know that a simple free pdf edit program will not do justice to such a task as they optimize file size at the expense of image quality. Firstly, the scans must be done at or above 300 dpi and line drawings must be edited into the pdf at a different setting than photos or text. Ignorance of this process is the reason we cannot read wiring diagrams in the 1970-1990 car OMs. Like everything else in life, there is quick & easy and there is excellent & rewarding. _________________________ http://www.ferrari308gtbi.com/
I have tested every conceivable item and believe Steve M's thoughts about the freq valve are right on....when engine was warm I uplugged the connector to the "buzzing" freq valve and there was no change in the engine's idle. I was up to now unable to plumb in my pressure guage (still looking for a good source of metric gas line fittings....ideas welcome) so could not check pressures. HOwever, one other thing.....I put a quart of Techron in the nearly empty tank, went the 3 mi to gas up, and saw noticeable improvement in the part- and full-throttle performance. So, I think there were at least some very dirty injectors (or other components). Next I shall pull all the injectors, have 'em cleaned and tested, and replace the rubber bushings. I made up a neat puller that I'll document and post when I get time during winter weather. And, if I cannot plumb into the lower chamber of the fuel dist. I will at least pull the FV and see if it opens when 12 Vdc is applied, as I suspect it has failed shut. Best to everyone, thanks for all the help! Ray
