I have just finished rebuilding my engine. New cam, ported heads etc.

On Christmas Day I plucked up the courage to turn the key, and the motor fired up right away. Ran like a pig , but no big deal, timing and fuel pressure still to play with.

The timing light showed me that the distributor was one tooth out, and one of the plug gaps was closed up, so I gapped the plug, pulled the distributor (HEI), and reinstalled it in approx the correct position.

Now, - nothing. The engine turns over, but does not fire at all. I have checked the distributor install, checked for 12v at the coil with the ignition on, checked all the plugs into the distributor, checked for fuel pressure, and all seems good. I have zip tied an old plug to the alternator body, and get no spark.

What do I do now? I have spent 4 hours checking stuff this afternoon and have run out of ideas.

Any help appreciated. :confused:

 

Can it be anything to do with the VATS system, or would that sop the starter motor froim turning :confused:

 

Is the problem "no spark"?If so I would check that the dist. is getting voltage.If not, run a hot wire from the battery.

 

The problem does seem to be no spark. I have 12V at the distributor.

 

All I can think of is ,put the dist back to it's original postion and see I it will crank.If not maybe you popped the module .

 

You could be right with the module - any way to test it?

I have a vacuum advance carburetted 305 in another car, is the module the same, can I substitute that one to test the theory?

How do you pop a module anyway??


[Modified by britvette, 7:05 PM 12/28/2003]

 

I quick dumb question.....is the distributor turning? If so proceed on.....

Did you check to see if you have spark at the coil wire? If you have a remote mounted coil check for spark there you may have a bad coil wire or a shorted out rotor causing the HV spark to go to ground.

If you don't have spark at the coil then using a 12v test light connected to ground probe the white wire on the negative side of the coil. It should blink when you turn the engine over with the starter. If not then the module could be bad. If it does blink and there is no spark at the coil then the coil is bad, be sure to double check the coil wire making sure its not open.

Next remove t he distributor cap, take a look at the module, where the distributor pick up coil is connected. Remove that connector from the module, then with the 12v test light connected to battery 12v positive, touch one of the module connectors where the pick up coil was connected. Watch for spark from the coil. Be sure that you are not touching the coil wire because if the pick up coil was bad this will fire the coil and light you up :eek:

If after doing that and you do not have spark then the module is bad. If you have a coil that is intergal to the distributor cap you can still do this test by leaving the cap connected and laying it to one side. And by removing the coil cover you can probe the negative side of the coil or just probe the white tacho wire.

Oh and no the module between your old 305 and your corvette are not the same. Especially if you have a remote mounted coil.


[Modified by tjwong, 10:12 AM 12/28/2003]

 

I think you should be able to use the one from your other car.

Not sure how you could've poped it, but I think they are a weak link.Some companys offer an upgrade as a replacement that gives a higher rpm.

Try the swap and keep us posted. :chevy

 

Thanks TJ, I need a bit of clarification here.

What do you mean by the coil wire. this is a standard HEI dist. 12v is present at the red(Batt) and white (TACH) with the ignition on. The black wire is bolted to the coil laminated core.

I will check for the flashing light at the tach wire, but I will have to make a test light first.

Any idea what the DC resistance of the coil should be? red/white/black?

Sorry to be such a pain, - just want to drive my car again!!

 

OK. so I have done the flashing light thing, bit inconclusive as the filament doesn't have time to cool between flashes. However the tacho shows 200rpm whist cranking, so I will take that as good.

Have measured the coil, 2R on primary, 7.5K on secondary, N/C primary to secondary. So I will take that as good.

Pickup coil measures 750R, N/C to ground. Good again.

Looking like the module, don't know how to test this, so will order a new one tomorrow. (Can't swap with my other car - forgot I have a Mallory system in there)

Looks like another 2 weeks off the road

:(

Thanks for the help and encouragement :)

 

How many connectors are plugged into the coil, just out of curiousity? There should be a red one(power), white one(tach), and a brown one with three wires from the computer. If that one isn't plugged in, the car won't spark.

:seeya

 

They are all plugged in.

When I realigned the distributor i failed to disconnect the battery, so I think I've fried the module. I suppose one has to pay to learn. :mad

Thanks for the input.