FM won't start

[Johnny B]

Time for my weekly FM ?

I recently acquired an AIM XG log system. Installed temporarily to test it. Fired up the car for 1 minute and everything appeared to be working well. I hard wired the system and now the car won't start. It could be flooding or no spark.
Replaced plugs, cap and rotor to no avail.
Any Tips,
Thanks all.

John B.

[Darryl Wills]

Make sure the hot wire to the MSD is still hot after the wiring job.

[Darryl Wills]

Also the hot wire to the coils is still hot

[formulasuper]

"It could be flooding or no spark."

First thing to do is verify that it does or does not have spark at the plugs.

[sflaten]

I have had this happen with start up and immediate shut down. It would flood. pull the plug, use dry plugs and crank over the engine with no plugs or blow out the chamber. Put the dry plugs in and try to start. Some time just dry plugs will do.

Typical issue with the FM is you need to learn how to shut down to avoid flood. When you want to shut down, turn off the fuel pump and wait for the carb to run dry. Avoids a lot of problems. If you spin on track, it has the same issue with restart. Use the typical flood clear by holding the pedal to the floor till it pops.

I learned these lessons the hard way. Good luck.

Steve

[JRMarchand]

Let us know if the car has spark, if yes then there is the removal of all spark plugs, turn the ignition off(msd off) and crank the engine over with the fuel pump off also, If you can crack the throttle while turning the engine over, more power to push the extra fuel out.

if no spark, make sure that, the two wires from the Distributor go straight to the MSD box(purple and green), unplug check connection and tape over. Check under the Distributor cap, make sure sure the rotor and cap terminals are in good shape. Turn ignition on and check for more than 11.7 volts at the kill switch junction where the MSD red wire is(heavier gauge), Make sure the MSD is properly grounded(black heavier gauge)

I believe the XG log uses one of the 8wires in the bus-wire for power/rpm, the rpm wire I think its the blue. You should want to make sure that for some reason or accidentally the wrong connection has been made with the tach/rpm signal wire coming out of the MSD, really not sure what would happen, but make sure, maybe back-track and disconnect the AIM and see if FM starts.

Toggle Switches go bad sometimes and sometime improperly grounded. Electrical scenarios can be confusing, its easy to think that you are soldering the two correct wires and you might not be.

I hope you got it started, let us know if you had spark.

[Johnny B]

Thanks Guys, it appears no spark is the culprit. Today I will remove the Aim system and see if it will start. Never was any good at wiring.

I'll keep you posted.

John B.

[sprocketmensch]

Recently installed a new digital dash and had my car stutter and turn off at speed. After a lot of trial and error, it turned out that the master DC disconnect was intermittent -solid enough to not show a voltage drop but not solid enough for the MSD. Changed out the switch and voila. Electrical issues can be quite tricky to tech out.

[Johnny B]

Finally success. Removed the AIM system and the car started. Installed the AIM again and everything worked except the tach. I tapped into a wire from the original tach and it started working. Not sure why, it's suppose to go to the negative side of the coil but I thought the orignal was still working so I had to try something. Ran the car long enough to get 160* before I shut it down.

Thanks Again,

John B.

[Mike Williams]

The reason is the MSD has its own tach signal out put and when you wired to the neg side of the coil it was a direct ground = no spark