ez efi help - Page 3

bluzman2004 · #21 (**permalink**) 01-06-2010, 09:46 AM

I have it on a 1978 car with a stock alternator (except for a chrome case) and it is fine. We put it on a 67 camaro with a stock alternator during prototyping and it was fine.

You don't need an special alternator for EFI, unless yours is bad or the wiring is not up to par. We have these things on test stands with engines and dyno tested them hundreds of times. None of these have ever even had an alternator. That battery is just kept up with a battery charger.

TurboNova · #22 (**permalink**) 01-06-2010, 12:29 PM

Too small of an alternator is a thing I have seen quite often, most of the guys switching from a carb to EFI still have the 65 amp alternator and that usually does not cut it. Often with todays audio systems, air bags, electric fans, fuel pumps, EFI, and igntions you find that 65 amps just isn't enough.

bluzman2004 · #23 (**permalink**) 01-06-2010, 03:02 PM

I thought he said his ECU wouldn't fire the injectors at startup? I hope you don't mean the prime fuel pulses it does when you initially turn the key on. I will only do that once and then never again until the motor has been actually started. This protects you from flooding the car by turning the key on multiple times without starting it.

If your electrical system doesn't have the capacity to fire 4 high imeadance injectiors while you crank the motor, no alternator will help. At cranking RPM the alternator isn't really doing anything. I think your problem is your battery is bad (or dying) or the wiring is bad.

TurboNova · #24 (**permalink**) 01-07-2010, 12:28 AM

Originally Posted by bluzman2004

If your electrical system doesn't have the capacity to fire 4 high imeadance injectiors while you crank the motor, no alternator will help. At cranking RPM the alternator isn't really doing anything. I think your problem is your battery is bad (or dying) or the wiring is bad.

Bluzman2004 is correct, the alternator does nothing during cranking. After it starts and runs then it is a factor.

But you can say a 65 amp alternator will work on something without any other electronics but start putting a big sound system, air bag pumps and all the other stuff that people are using now and then you will find it is not enough. A bigger alternator can never hurt.

MetallicaChad · #25 (**permalink**) 03-06-2010, 11:35 PM

i have a 79 c 10 with dual tanks also. i found this online and was wondering if this will work just fine?

part # on jv witney is 15712G since i can post link on here yet. says its good up to 65 psi

also i cant find a wiring diagram in my chiltons for the switch and selector valve but am guessing there are just as many wires on this new one as the old.

gregsezefi · #26 (**permalink**) 03-07-2010, 09:33 PM

I had the same problem. Try using a 12 volt testlight. Touch different fuse points that are not being used by other units (heat, radio, AC, etc.) with key on...then turn key to start... if the light stays lit then you can hook the pink wire (12Volt Switched) to this spot. When you turn the key off and remove it... the test light will not light and the ECU will be off.