no fuel during cranking

This is going to be long, so I'll apologize now.

I have a 1947 Packard with a 350 in it that I have converted to EFI. Last year I took the plunge after driving the car to from my home in North Dakota to Colorado and back though Yellowstone, across Montana back to ND. After that trip I decided that fuel injection would be the way to go.

Fast forward to now. I have used the entire TBI setup from an 88 suburban. The issue that I am having is that there is no fuel pulse from the injector when cranking the engine. When I pour some gas into the throttle body it fires right up, the injectors spray, and all is good. I have had the car running and driving for over an hour. I have changed the ICM, IAC and the temp sensor. I have verified that the TPS is good, and inspected the pickup coil as well. I also have verified that the ECM (1227747) is getting the appropriate voltages both in and out, and I have used a test light to verify that I have a constant 12v at the injector during both crank and run positions of the ignition switch.

Now if the the ECM sends out a ground pulse to the injector to "fire" it when the engine is running, then why am I NOT getting the ground pulse during cranking to start the car?

Any thoughts or ideas? I'm out of them.

This is actually a pretty common problem. Even though you've checked for power in crank and run positions (check the coil and harness), it's a common enough problem that I tell people to triple check this before troubleshooting any further. A quick way to eliminate this as an issue is to wire everything to battery hot (make sure you can disconnect quickly), if it starts fine that way, then you do have an ignition switch problem. I have seen a bad pickup coil cause the same issue, but that's pretty rare.

Sounds good, but what am I looking for? I've got spark during cranking, Could you expound on this?

did you change the icm trying to get it to run? if the fuel pump runs the injectors proble are not pulsating.are you going to put some pictures up of your Packard? :jfj:

ony , here ya go!

Vats turn off injectors at cranking, but not when engine is running.
It is one very possible reason. Do you have vats system disabled?

Wow... What a beautiful car.

There are a few directions this can go. You might not have fuel pressure at the injector during cranking. The injectors could be turning on but with no pressure behind them you will not see them open. If the fuel pressure power supply line is not connected to a source that has power durning crank then the pump will not activate during cranking. A simple check might be to jumper the pump to battery power and crank the engine. If it starts then check the fuel pump relay and wiring for power during cranking.

The ecm may not be triggering the injectors. This is not difficult to test. The easiest way to test is to use a product called a "noid light." Plug it into the injector and crank the engine. If the light blinks then the ecm is triggering the injector. You could also connect your test light to B+ and to the injector ground wire. Make sure the injector connector is disconnected first. Same test; crank engine and watch for blinking. Don't crank for too long though. If the ecm is not triggering the injector then you need to determine whether or not the reference signal is present during cranking. Chances are the ecm is receiving the signal since the engine will start.

I do not remember any 7747 application having VATS (chip key security system). I could be wrong, though. If the ecm is from a truck it did not have VATS.

At no time should you use a test light to ground the injector to see if it fires. This can cause the injector to fail.

Good luck.

I had that problem with my 83 conversion. Turns out part of the fuse pannel gets turned off during cranking, like the radio. Try wiring your injectors to a portio of your fuse box that stays hot during cranking. This can be done by monitoring different spots in your fuse box with a volt meter while someone cranks the engine.