57 swb 454 NO SPARK??

[la hi]

I put the 454 back in Tthe truck and I have no spark when I place the plug on the frame. The engine rolls over just fine but will not start.
The two delco elect ign wires are connected. i swapped them around and still no spark. Alt wires seam to be correct as I labeled all the wires before removing the engine.
WHAT WIRE AM I MISSING??

[mr48chev]

Someone will probably add to this but I am thinking that with the stock 57 ignition switch you have to have the resistor bypass wire from the R post on the solenoid to the + post on the coil hooked up to get power to the coil when you are cranking the engine over. I've fought that battle in the past and I think that is the way the stock switch is set up. A well tuned engine would start when you let off the key while cranking it and the ignition went to "on" with the crank still spinning enough to fire the engine.

Other than that:

Points not adjusted correctly or contaminated with foreign material.

Polarity of coil wrong you need the + post hooked to the wire from the switch and the - post hookd to the wire from the distributor.

Forgot to put the rotor in or broke the rotor. Sounds funny but it does happen.

[la hi]

thanks i will follow the wire back to the switch. then check the quality of the wires where I made them longer.

[1-ton of fun]

What distributor are you using?

[la hi]

GM electronic dist that came with the engine. it has two wires that go inside and I have not followed them back to where they go yet. Probably tomorrow.

[mr48chev]

OK, you need the page on hooking up an HEI distributor.

It really helps when guys give us all the details when asking a troubleshooting question so we can give the correct answer.

You are going to need a key on power source that is on even when the engine is cranking. Usually there is a pin on the fuse block that has power when he key is on and still has power when you are cranking the engine. If not you need a heavy gauge wire (8 or 10 gauge) to run from the ign post on the switch to the batt connector on the distributor. The other wires coming from the distributor body connect to the cap in the slot (s) behind the Batt and Tach pins.

Here is a link to a NAPA service bulletin that I got from a Napa ignition in the early 80's and have used to trouble shoot HEI ignitions with ever since http://s173.photobucket.com/user/mr4...?sort=3&page=1 It also explains what the wires do.

You might still have to run the bypass wire from the solenoid to the ign wire that goes to the BATT pin on the distributor if you don't get power there when you are cranking the engine. That would be the simple way to solve that.

[OrrieG]

Block grounded? Hei needs full 12v dedicated wire. Other connection is for the tach.

[la hi]

ok! I cleaned up the ground connections for the engine, battery, and cab ground cables.
I attached a wire from the starter battery connection to the bat term on the HEI distributor.No action

I connected the ign wire from the bat term from the dist to the ign post on the switch. Now that is a continuation of the wire from the starter to the bat term on the dist, then to the ign switch. no help

I still do not have a spark on the bare spark plug wire.
The starter will roll over and no spark to the spark plug.
any suggestions?

[OrrieG]

Sounds like you are getting 12v to hei, check with a multimeter. I suspect the hei but know nothing about them, or how to trouble shoot them.

[Apachemike]

Deep breath. Can we start from the beginning:

When you say put the 454 back in can I assume it was in and running before you took it out? Did anything get changed in the wiring after it was out?

[la hi]

YES It was running and running fine. A slow start when it has been sitting for a couple of days.
I removed all of the front end, engine, and installed an IFS.(heidts superride II) I labeled the two dist wires, which one is pink and the other sort of red. The left one is the battery and the other is the tack. I labeled the alternator wires,temp sender,oil sender, fan/radiator sensor, and the connector. They all went back into place.
The engine rolls over, will not start with priming it. So I checked a plug wire against the block, and no spark.
I spliced a fused wire from the starter battery connection to the batt connection wire on the distributor. The that wire goes to the IGN post on the key starter switch.
Same result. I left the wire off the IGN pole, same result.
All of the other wires in the front (radiator fan, head lights, parking lights I cut off and will replace when I put fenders, hood, grill, etc., back together.
thanks
larry

[Apachemike]

Ok, actually sounds like bad coil or module. First step I would take is return all the wiring back to how it was when you removed the engine....not worried about lights and such, engine harness because it worked
Module can be tested at any autozone, etc. If it's bad have them test your new one BEFORE you leave the store. They are known to have a high failed new rate.

On the coil, Remove and invert the cap, Measure between the tach and BATT terminals , using a DVOM, Set to OHMS scale, RX1 and calibrated to 000. It should read less than an ohm, but more than 000, If not it's bad.

Next measure the secondary, set your DVOM scale to RX10k or higher..put the probes between the BATT and the carbon pickup for the COIL..it should read between 6000 and 30,000 OHMS..Outside of that range toss the coil and get a new one.

[Russell Ashley]

Before you buy a coil or module, change the rotor. It's the cheapest part, and the only part of an HEI that has left me walking.

[la hi]

Summit Racing SUM-850030 - Summit Racing® GM HEI Ignition Tune-Up Kits

I changed the cap. I am thinking about the HEI Ing tune up kit listed above. That may be a solution to the problem and improve the spark. OR NOT!

I will take a break and think about it.

[OrrieG]

I still say break out the multimeter and start tracing the power to and thru the ignition circuit before just randomly changing parts. I have been frustrated more that once with a R&R that would not start that ended up being a connector or wire that got damaged during the process. Think basics; analyze, isolate, then repair/replace....

[Apachemike]

^^^ Agree. Next step is to test the HEI power (should be pink or red) wire going to the HEI. Check for 12v with the switch in run start

[52mikey]

i had that issue once and disconnected tach wire, it was grounding ignition.

[la hi]

Got back at it today. the green tack wire went to the ing switch. dah! that is the bat wire from the dist. changed it and it started.
thanks for the help guys, I would not have fixed it with out you

[OrrieG]

good to hear is was simple and worked out...

[la hi]

one last problem. the tach does not work. it worked before, wires are still connected the same. the one wire goes to the number 4 terminal on the dakota digital power unit. That is labeled tach. the other still goes to the key switch IGN post.
should I run a power wire from the starter to the coil to give it constant power?
or forget the tach for a while since it runs great?