4/30/2024 0 Comments Degree advance on a timing light![]() ![]() I do not suggest trying to check timing with a hand held timing light with engine speed over 2,000RPM. As a plug for my part-time business, I rebuild and recurve Ford distributors. Todays fuel and unique driving habits will dictate final timing. So,if you have a 13 degree limit internal (26 degrees at the crank) and you want to limit your total advance (w/o vacuum advance) to 36 ,set initial at 10 degrees at idle w/vac line disconnected. Some are 10,13,15,18,etc Those are distributor degrees so crank degrees are twice that. There are a few different limit slots available. BobOĪs noted above,the distributor has an internal limit that will be very important in your timing decisions. Now I better take cover here comes the flack lol. I know this is strange but many times I've heard that everything was done as exact as could be but then having to turn the distributor advance to where it almost touches the thermostat housing to run right, well this means although it's running better the cam is still retarded and will run hot after a long while. The problem is I think that not all cam to crank allignment is exact and some are a half tooth off, this happens frequently because the new chain doesn't go onto the gear exactly and one link must slip to one side or the other of a cam gear tooth, if that half tooth slips in the advanced direction zero should work, if it goes on a half tooth retard the 10 degree mark should work. thanksIf you install the distributor with the pointer to zero on the ballancer and the #1 piston at TDC compression and it runs irratically or hot it is retarded, you will need to install the distributor with the pointer on the 10 degree BTDC instead of zero. ![]() i don't know if the distributor has been curved. At lower temperatures, knocking occurs at a later point and results in lower RON factors.My ford book says 12 deg btdc is that enough or will it take some more. These reference values apply at outside temperatures higher than 25 ☌. The reference values refer to the following: The RON factor serves the purpose of determining the fuel quality used. There is also a data item AutoEnguinity calls RON Factor that will indicate the approximate RON octane of the fuel used.įuels with a low octane number may be the cause of the following problems. It shows a range for the ignition timing of -23.60 - +71.60 whan I graph it, but it also shows the max rpms as 9000, so not a real BMW limit. You should be able to see a data item for the Knock sensors, I believe my AutoEnginuity software shows a voltage of from 0 - 5 volts from the knock sensors. Here is a graph of my 330Ci at idle (mostly). Graphing the throttle angle, engine RPM, vehicle speed and ignition timing will tell you quite a bit. Loss of ignition timing is probably the quickest way to loose/reduce power as there are only about 4-5 things the DME can control, fuel volume, ignition timing and VANOS and then of course ICV and throttle on drive by wire cars.Įven 1-2 degrees loss in ignition timing can be felt. As I recall when foot is off the throttle in fuel shut off/coast mode the ignition timing may jump back toward 0 degrees or even -5 degrees? Been a while since I really tracked ignition timing. Timing should peak around +30 degrees depending on conditions. In general terms, once warmed up as long as the IAT temp is not too high, the ignition timing should be around +15 degrees at idle and in general terms as the engine RPM increases so should the ignition timing. This is part of the 2800 Stutter Thread that is on the forum here. Usually it is not the knock sensor pulling timing but a screwed up BMW DME programming. Set up Torque Pro to capture data, it can and will capture timing advance.
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