Stephen0523

Hello all my 307 Oldsmobile Delta 88 1984 cranks very well but all of a sudden had no spark. I just replaced the cap, rotor, ignition coil and button but still no spark any ideas what I should look at next?

Oldsmaniac

With key on make sure you have 12v at the coil lead on distributer cap. Look for cracked wire on pick up coil in distributer.

droptopron

Put the old parts back on & see if it starts. New parts can be defective

Stephen0523

Oldsmaniac

Check Youtube for GM HEI

oldcutlass

If you look at the top of the cap where the wires plug into underneath, there are 2 markings. 1 is for batt (coil+) the other is tach (coil-). See if you have power at the Battery+ terminal wire with the key on.

droptopron

Any chance you left out the coil contact that goes between the coil & the cap? (kinda bent up wire lower right corner of the pic)

Stephen0523

I have everything installed except Circled in red attached.

Fun71

There's your problem. That's the ground connection.

Stephen0523

Stephen0523

cherokeepeople

lets clarify this.the way it sounds it was working fine,til one day you went to start it and no spark,so you decided to start with the cap,rotor and coil??my guess would be the module took a dump.or as mentioned a wire on the pickup coil.

Fun71

So how does that black wire get connected to the vehicle ground (battery negative)?

oldcutlass

Did you try advancing the distributor a bit while someone cranks the engine?

Stephen0523

Hi olds cutlass, I have not tried advancing the distributor. That would not resolve why there is no spark? I think I may replace the module & the little diode

oldcutlass

Sorry I thought you fixed the no spark issue but it still would not fire.

Stephen0523

Sorry, still no spark. I have 12V on the coil, but the module and diode looks rough, never been replaced, so that will be the next step.

cherokeepeople

make sure you put the grease under the module before you put it in.

Stephen0523

Grease under the Module, hmmm, it was dry as a bone. The 2 part shown (The Ignition Module and the diode will be replaced next)


.

cherokeepeople

there should be a little grease pack with the new module,its for heat transfer,

oldcutlass

You don't need a lot of the heat sink compound on the back of the module. The silver can is not a diode its a capacitor.

Stephen0523

Different prices on these modules.
Anyone know what would be the best? Is more money better?

https://www.summitracing.com/int/sea...keyword=module

oldcutlass

Not necessarily, go with the DUI or the A/C Delco.

Fun71

Agreed, quality brand vs price. Also note some of those are 7 pin modules for CCC systems.

76olds

I like the DUI module myself. However A/C delco, Accel are just as good.

Eric

Stephen0523

capacitor & module ordered. Fingers crossed she starts!

Stephen0523

The module and capacitor arrived yesterday. On the back of the module should I put dielectric grease or just regular grease?

Fun71

You really need heat sink compound (zinc oxide paste) for that as it assists greatly with thermal conductivity. Heat is what kills electronics, and using the compound helps the module transfer the heat it generates to the aluminum distributor housing.

Stephen0523

so zinc oxide paste is that dielectric grease we use for spark plugs we Use for spark plugs or or nickel grease that silver stuff?

Stephen0523

New Module and Capacitor installed, still no start.

Stephen0523

Sorry for the late reply on the subject life got away from me!
It ended up I had cracked I had tooth on the timing gear and the chain was broken!
But I was glad I replaced all the ignition stuff , she fires right up and runs great!

Thank you all for your help!

oldcutlass

Glad you got it taken care of.