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On 27 Feb 2001, at 9:45, Douglas_Brashear@amsinc.com wrote: > Exhausting all my own ideas, I took the car to a local shop...although > I thought the engine and all related bits were absolutely the original > for the car, they said that after looking up the serial number on the > ECU and distributor, that the correct timing is not what is shown on > the timing sticker. I'm planning on re-looking up those numbers so I > know the correct timing setting for myself. They're right that the tune-up specs must be done according to what the engine is, not what year the body was made. Post the engine #, ECU # dist #, etc, and we can try to verify what year you should be treating this as. A 73 is much easier to set up than a 72. > I had a Bentley, but for some strange reason I must've sold it with my > old 69 Square. Jim, if you have spare old copies of both books I'd be > happy to take them off your hands :-) Name your price. I'll send you that info when I get home tonight. > I have a timing light and would consider myself rather skilled at > setting timing. My vacuum advance unit is somewhat new and holds > vacuum well. The advance unit seems to do what it's supposed to > (checked using my timing light) but I'm not sure how to measure that > it's making it to the necessary max advance. Probably in Bentley? > Now that I think about it, the car seems a bit rougher at speed, > possibly suggesting that the advance curve isn't what the car is > expecting, or it's not reaching the max advance...I'll check the part > number on the vac unit to be sure it's the correct one. 73 should use a 505 vacuum can. > As for the injectors, visual inspection reveals that no fuel is > leaking from the hoses or injectors. The fuel lines are all new and I > removed the crimp-on clamps securing the small segment of hose to the > injectors in favor of double hose clamps and 90 PSI hose segments. > When I thought they might be leaking, I thought maybe they're dripping > into the manifold, to the point that the engine can't fully regulate > the fuel intake...the injectors drip into the manifold (not making a > good seal when closed), the ECU senses the additional fuel and cuts > off the supply, the car almost stalls, the ECU adds more fuel, the > leak occurs again...hence, my slight surging problem? The ECU has no way to measure extra fuel drips; it can only sense temp, manifold vacuum, and RPM. It is more likely that your idle is just set a bit high and this makes the engine lope when it senses an idle speed that is too high. This produces a VERY pronounced lope, but if your symptom is more subtle, there is probably a different reason. There are several possibilities, but you need to check all the standard tune-up items first. Another thing to check is the charging system regulating voltage. With the engine warmed up after a drive, measure the battery voltage with the engine running at medium RPM. The voltage should be >14V (14.1-14.4V.) If it is less than 14 the voltage regulator is worn; if it is less than 13.5 you should replace the VR. - Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ------------------------------------------------------------------- List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org