gm 305 electrical problem?

[sarantis]

Hello everybody
GM 305 year1980
May someody tell me if 4.7V on the + of the coil is enough ? Where is the resistor and how many Ohms should it be?May it be inside the solenoid at the back of the portside manifold (because i have the 4.7V at a pin of the solenoid?
When the engine warms up and you try to run it behaves strangely.As some cylinders do not work properly or at all.Spark seems weak but i don't know how is the proper one.I 've changed fuel pump but nothing.An electic diagram would be very helpfull
Thanks in advance

 

[firehog6305]

Re: gm 305 electrical problem?

this is from another post hope this helps, couldnt find the coil info, my manual in on the boat in berth


http://forums.iboats.com/showthread.php?t=167035

 

[sarantis]

Re: gm 305 electrical problem?

Thanks for your reply Firehog but in my case it doesn't help because the bulb doesn't care for one or two volts less to light up.If some time you can drop a look at your manual and priv. mail me to notice it i would be gratefull

 

[firehog6305]

Re: gm 305 electrical problem?

no problem, I'm going down to the boat today and staying the night, if nobody gets back to you before then, I will sent you the info, I have 2-305's 1978 in my boat

 

[THE BEEF]

Re: gm 305 electrical problem?

I think you should have 12v at the coil . I believe the coil has a internal resistor.
You might want to start back at the battery clean and tighten all connections.
You just have to follow the path and keep checking for a voltage drop. I think the wires plug together at the top by the shift converter, you can pull them apart check for corrosion and do voltage checks.
Later
Beef

 

[sarantis]

Re: gm 305 electrical problem?

I have 12V but when the cable + is on the air.So i have to Know where is this resistor.If somebody else may assure if it's inside the coil or not then it's much easier for me.Thanks for replying

 

[sarantis]

Re: gm 305 electrical problem?

I feel stupid.Although i had been told that distributor gives and cuts the ground of the coil i kept measuring the voltage at the + and - of the coil.When i used as - of the voltmeter the chassis the + gave me the 11.5v i was looking for. Now the problem turns to mechanical and i'm sterting a new thread...

 

[bruceb58]

Re: gm 305 electrical problem?

The voltage depends on how you are measuring. Is the engine running when you are measuring the voltage?

If the engine is stopped, you can measure from the + to - on the coil as long as the points are closed.

Some ignition systems have coils that have internal resistors...others use external resistors.

 

[sarantis]

Re: gm 305 electrical problem?

Thanks for the advice,do you have anything to suggest about my other thread with the valves?Do you know if gm305 1978 has gears or timing belt and if it needs checking ever?