Setting pump primary timing by milli volt method.

[barry123400]

Sorry guys it was my brother in laws old jetta. He had just installed a used pump. But principal remains the same. Decided to set for average hottest burn. So read all glow plug voltages combined by reading the general harness. Was 15mv he had the pump set by ear. Loosened and tapped pump until hit maximum point of 36 mv. Did not expect that large a voltage swing and it suprised me a little. Also read three other volkswagons on the property. two were reading 15-20 milli volts and one was 66 milli volts. Do not know if the wide varience was newer glow plugs or older plugs. Was not leakige from the relay as with key on and engine not running there was almost nothing read on harness of the high reading car. These three were not adjusted but just was curious about what would be read from them. It is obvious there will be no standard values and it does not really matter. Went a litttle past with voltage tapering off on the one I was adjusting.. Reset to 36 mv. Told him that since his injectors had never been checked there was a possibly the average highest readout would probably be the best. Better than setting to one unknown injector at least. No noticable pre ignition was present after or before the adjustment. He changed the pump out because of fuel leakage not general performance issues. Just told him to see if milage was normal as well as performance as he like myself has been driving old diesel volkswagons for years. What I would like to have done is check the timing by the conventional method to see how it stacked up. Just decided to see how it works out instead. Milage and smoking should confirm if it really is in the ballpark in a few weeks. Garage cost to set pump timing is about 240.00 average here as you require an adapter to screw into the pump as well as a dial gauge to get the readout. If he has no problems with it's setting might do it the conventional way to establish if to design accuracy. Also a possibility the milli volt is a better setting that the factory recommended now exists as it does deal with aging syptoms of many forms where the factory method does not. It will take time to prove that though. Have to wonder how close it is though. Again more has to be known but my first thought is how quick and painless it is to do. If a scribe mark was put on any pumps present position and it moved to the highesty voltage reading nothing would be lost by trying it that I can think of. You could always return your pump to where it was. Now hoping someone out there will time with the drip method and just do a simple comparison by marking the highest voltage point read before and scribing a mark. If you do the drip method right after that and they turn out exactly the same then for practical purposes this will be the better, quicker, and perhaps more accurate way to time the 123 engines. Again a little more feedback will and should be generated. Two noticeable items were the quick response or voltage change when tap adjusting. Almost instantainious for practical purposes and how such a little tap was changing the voltage. My two cents for what it is worth. Not meant to be a suggestion af validity by any means just a description of what transpired. Gathered a crowd of guys and the first common observation was the speed of the process if valid. Five minutes can reset a volkswagon pump from start to finish with the accuracy of the proceedure still unknown.