HEI: ballast resistor for stock coil? 1988 2.0L

[borlax]

When using an HEI module with a stock canister coil, do I need a ballast resistor going to the coil to control the voltage while the engine is running? I've heard 12 Volts is ok for the TFI coil, but heard of over heating with 12V to a stock canister coil. Thanks for any help

 

[kimcrwbr1]

Yes you do. If you have starting issues get a diode and run a wire from the start solenoid through the diode to coil pos to prevent backfeeding power to the solenoid. The best option is to just install a TFI coil the square one.

 

[kimcrwbr1]

In my opinion

 

[kimcrwbr1]

Looking at the schematic for the 88 2.0 it should already have the start circuit have you check the voltage at the coil with the key on. There is a ballast resistor wire available at autozone. Put the volt meter on coil pos and a good ground and turn the key on it should read 9-10 volts and then start it the voltage shoul jump to close to battery voltage and return to running voltage when you let off the key.

 

[borlax]

volt meter setting

Thank you for the help. I'm installing today. What setting do I use on the voltmeter? One under DCV? I have one, just don't know how to use it

 

[RonD]

Any single coil/distributor system should run a ballast resistor or resistor wire(GM) to power coil when running, regardless of what is "spec".

System power when engine is running is 13.5volts to 15volts, not 12volts, because of alternator.
Ballast resistor will drop this down to about 8-9volts to prevent coil from overheating and failing

When cranking the starter the batteries 12volts drops to 10 volts, with ballast resistor as the only power source the coil would only get about 6volts, this is why you want a Starter wire for the coil that is active only when cranking.

Ford 4 post Starter Relays(solenoids) have a post just for this coil power when starting.
The "I" post, I = ignition, this post has 12v(10volts, lol) when starter is cranking engine.

Or you can add a wire from Starter Motor Post, it has 12v only when cranking, and run that to "+" on the coil.

In either I would use a Diode to prevent the 9 volts from resistor wire to flow backwards to Starter relay.
A diode is a one-way street for electricity, if you hook up 12v to one side and check voltage on the other side it will be 12v, if you hook up 12v to the other side and test again it will be 0v(or almost 0v), one-way street.
Vary handy and cheap electrical component

 

[borlax]

HEI starts and fires but wont stay running

I installed my HEI module today and it turns over and fires but wont run. The only way I've gotten it to stay running is to take a grounded wire tester (the one with the light bulb and needle tip) and hold it on the G tab, turn the engine over and then while its cranking quickly jump from the G to the W tab - and keep it on the W tab, or it shuts off. Any suggestions?

 

[RonD]

Did you Ground the module?
It needs a good ground wire, G, W, C, B are "control" connections, Ground connection is on the HEI case

G and W are the "points", these are connected to the position sensor in the distributor

G = sensor -
W = sensor +

C is the coil control wire so goes to "-" on the coil
B is the power from ignition switch, it needs power in START and RUN key positions, reads like yours only has power in START position

Do this simple test:
Run a jumper wire from Battery + to Coil "+"
Try starting, after it is running remove jumper, if it dies then you have wrong circuit connected, you need a RUN circuit.
Also the START circuit with cranking

 

[borlax]

Runs but shuts off sometimes

I got it to stay running for the most part. I hooked a ballast resistor from the battery to the + on the coil, with a toggle after the resistor - before the coil. The resistor is from an early 70's Mopar. That's all I could get. The coil is fairly warm but I can leave my hand on it after driving 30 miles on the freeway. I warmed it up and drove 3 miles to get gas and when I let off the throttle to pull in it died. I got it to start again and made it to my exit on the freeway, but It kept dying when i pushed in the clutch and let off the throttle. I had to keep starting it and give it high RPMs to stay running at the stop lights. Other than that it drives fine. I don't know whats going on here so any help is appreciated. All I can think of is to go to a TFI coil. And for that I've heard to use a resistor for around 9 volts no matter what spec is, and also that a straight 12 volts is fine. Maybe the ballast resistor is causing problems?

 

[RonD]

If possible measure the voltage at the "+" coil when engine is running, alternator should be running the rest of the system at 13.5-14.5vDC so with ballast resistor Coil "+" would be closer to 11vDC not 8-9vDC, so no, that shouldn't be the problem.

But you can run without ballast resistor to see, coil doesn't explode or anything
Long term, i.e. months and months, running at the higher 14vDC can damage coil, short term is not an issue.

What advances the spark timing on your distributor?
Centrifugal or vacuum

And what is the base timing set at?

 

[borlax]

The advance is both vacuum and centrifugal. It's a stock 2.0 duraspark distributor. I don't have the vacuum advance hooked up for now. I tested the + side of the coil and its reading 12.75 volts. Its getting quite hot after driving around for a bit. The base timing is set at 6 degrees but today I hooked up the Holley 5200 and it doesn't seem to be any good at all. The stock 1 barrel carter yfa carb picked up rpms a lot quicker. I set the air/fuel screw with a vacuum gauge on the manifold port.

 

[borlax]

I got the TFI coil

The stock coil kept overheating so I bought an MSD 8227 TFI coil. It flows through the high rpms before i shift much better compared to before. It still has the stock 1 barrel too. I sold my adapter for the Holley 5200 before I took it to my grandfather and found the float was unhooked. So I am waiting on the new adapter to arrive.