This is a screen shot so sorry for the small print.I realize this is microsquirt related.just figure the hard parts work the same.same parts numbers.just opposite rotation. Screenshot_2018-06-21-04-33-26.jpg
This is a screen shot so sorry for the small print.I realize this is microsquirt related.just figure the hard parts work the same.same parts numbers.just opposite rotation. Screenshot_2018-06-21-04-33-26.jpg
Jeeper
87 sjimmy powered by a 92 cadillac 4.9L pfi on 7427pcm /700r4/ 8.8 3.55 rear/disc brakes.
The signals that go to between the module and ECM are not affected by the coil connection. Reversing the coil will not affect the signal levels or what the signals look like as they switch on and off. However, reversing the coil messes with the signal conditioning inside the ignition module and will change the timing of the signals going back and forth between the module and ECM. In other words, the coil reversed messes with the timing, but it's not something that can be corrected in the ECM or that the ECM could even detect by watching the signals it receives.
The last time I set-up a TBI I set the timing marks to 10* and then aligned the reluctor teeth. It started fine and was fairly close to the 10* base timing I wanted to use. So, I'd still say that lining up the teeth a TDC and then seeing close to 0* base timing once started says the coil is correctly connected.
The distributor is built for that rotation, correct? I'd fully expect that if you ran a distributor backwards, the rotor would be off from the posts. On a clockwise rotating distributor, the posts should be further clockwise from the rotor location when the cylinder is at TDC. The location should allow the rotor to hit the post as the timing advances through the ~10* to 50* range of the timing advance.
Ok so my engine and distributor are a factory set up.ccw is the direction it was designed to run.so being that all the hard parts are the same and wired the same (only diff from a corvette dizzy is the lower half uses a shorter configuration so shaft. gear .and lower part of casting is all I see different)but spins ccw instead of cw.so my question to this is it must be the ecm that receives the output signal it requires.so the factory cadillac ecm received a ccw rotation signal. I'm using a 7747 that received a cw rotation signal.so does running it this way make the ecm think the signal it's received is not right. Is this something I'd see some how in logs. As I said.it just has this said light miss feel to it that I have not been able to solve.I hoped this would be clear and easy so as to eliminate mechanical issues that my spark plugs say are not there.but thanks for more info.your help is greatly appreciated.
Jeeper
87 sjimmy powered by a 92 cadillac 4.9L pfi on 7427pcm /700r4/ 8.8 3.55 rear/disc brakes.
I'll try to spell it out clearer. The signal the ECM receives from the ignition module have no direction information. It's just a pulse each time the ignition module detects the reluctor teeth pass each other.
Thank u for clearing that up.I'm gonna post a current bin and logs etc.maybe someone can have a look and tell me if I have the correct info to aquire correct data and if anything odd stands out.I've never done any other ecm tuning b4 so I'm unsure of if the data I'm getting looks right at all.thanks for your time.
Jeeper
87 sjimmy powered by a 92 cadillac 4.9L pfi on 7427pcm /700r4/ 8.8 3.55 rear/disc brakes.
ARPC 91 C-K Truck 5.0TBI 5 speed.bin
-1227747-V5.9.3.xdf
-1227747-V5.2.adx
NT6.xdl
NT7.xdl
Engine 1990 cadillac 4.5
Ecm 1990 7747
No egr
No smog stuff
No ac
Some things are off in bin for data logging.thanks
Last edited by S.O.B.B.; 06-22-2018 at 05:40 AM.
Jeeper
87 sjimmy powered by a 92 cadillac 4.9L pfi on 7427pcm /700r4/ 8.8 3.55 rear/disc brakes.
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