No throttle response after installing a new ignition module.

[ikeepmychevytoo]

This is my beloved Chevrolet Celebrity, with twenty-one years of experience and with that classical HEI ignition. Lighter emissions on this Canadian so the ignition module has only four terminals. Two for reference pick-up coil, and two for interrupting the ignition coil. No hall effect sensor or no electronic advance within the module. Very basic electrically.

All of a sudden it quit, after cooled down for a while it worked for the last time then quit eternally. Order arrived with a wrong part so I had to buy locally an aftermarket replacement part (Si Switches). It's resistances were within specs so I never thought it would be a problem. But now car is sluggish after 40 mph, very sluggish after 55 mph. This baby used to love to slant that needle quick past 55. It's like a built-in cop

I did installation very carefully, taking time, cleaned the base and spreaded new silicone grease for heat sinking. What could be wrong? Is this something known that non-Delco's don't work correct on ignitions? Is it worth to order the Delco one just for a try? Or during the process some other parts, coils are also ruined? (but defected part doesn't let electricity pass to ruin things

)

Thanks for reading... any insights would be appreciated.

 

[ikeepmychevytoo]

Well, I saw the light. It is between the dipstick tube and the sparkplug cable of the #4 cyinder

May be this is which ruined the original module in the begininig.

Plugs are fairly new, plug cables were repleced 3 yrs./30K kms before. What to do now? What is the first thing to do?

By the way, I have a problem with the Shop Manual's terminology with the resistences for the ignition coil;

•One lead and ground spec. is "very high or infinite". It reads very high when cold, 8K ohms when hot. Is 8K ohms very high?
•Between the leads spec. is "very low or zero". It reads 1.3ohms cold, 2 ohms hot. Is this very low?

Would you replace the coil?

 

[George7941]

The 8K for the secondary and the 1.3ohms for the primary are fine, pretty much where they should be. What I don't understand is why there is so much difference between your hot and cold readings. Either your coil is overheating or you are not measuring the resistances correctly.

 

[ikeepmychevytoo]

Thanks for the reply George...

It sits on top of the thermostat housing (it is not that on cap variety). I've measured multiple times of heat cycle with similar results. Probably it is overheating.

Should I replace the coil, or every other thing but not the coil...

 

[George7941]

What you should do is to hook up a ignition scope and see if you are getting full output. If you don't have access to a scope then just substitute a known good coil (virtually any automotive ignition coil will do for testing purposes)

 

[eljefino]

So is the module within the distributor, and does the distributor have vacuum advance? That vacuum advance could be left off which'll really make the car a dog.

 

[ikeepmychevytoo]

Yes module is within the distributor and have the vacuum advance... well I'll look into that. Already got a new temp. vac. switch. What bugs me is that a wire sometimes arcs to the adjacent metals before the plug. It is even audible!

Thanks for the insights, novodays I will look closer into this.

 

[eljefino]

Actually I'd put all new plugs, wires, and a coil (cap and rotor wouldn't hurt) all at the same time. You've got carbon tracking from all that lightning that you're shooting around.

If you reuse some ignition parts the misfire tracking will spread like bird flu to your brand new bits.

The coil is likely overheating from all the shorting out.