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Sun Apr 22, 2012 1:44 pm

We have a 69 bay window, 1600cc sp. Distributor is petronix flamethrower.

The story:
Yesterday I tried starting, no dice. Drained the battery trying to start it. Tried push starting, wouldn't go. Discovered bad coil, replaced with a good spare (not new). Charged battery.
Got new cap and rotor in mail (old ones were looking bad) and replaced.
Triple checked that the spark plug wires are in right order on cap, and the wires are on coil correctly.
Never messed with carb or turned the distributor.
Tried putting old cap and rotor back on in case the new ones weren't right.

Now,
Turn the key and the engine tries to start but just backfires with puffs of black smoke out of tail pipe.
What is going on?
How do we fix it?

Thanks
Jeff and Tracey

Sun Apr 22, 2012 2:31 pm

Open up the distributor and grab the rotor, lift it slightly anf give it a twist, if it turns more than a few degrees and doesn't spring back to where you started the distributor has hopped out of it's drive, you'll have to reseat it properly and retighten the clamp. If that test fails try a test light between #15 and #1 on the coil and see if it blinks when you crank, those electronic modules are known to fail.

Sun Apr 22, 2012 3:27 pm

checked the rotor, it sprang back nicely. The coil we put on was old but when we checked it, it seemed ok. My wife is headed up to get a new coil and see if that fixes the problem

Sun Apr 22, 2012 3:39 pm

If it's backfiring there's an ignition source somewhere.

Sun Apr 22, 2012 4:22 pm

we did nothing to the timing....just changed the cap and rotor and coil, why is it back
firing?

Sun Apr 22, 2012 4:45 pm

new coil...nothing has changed, checked the plugs and as expected they are very black and sooty.

Sun Apr 22, 2012 4:58 pm

Please try the test light test, or put in a set of points just for kicks.

Sun Apr 22, 2012 5:00 pm

even tho we got a new coil?

Sun Apr 22, 2012 5:01 pm

Whatever is going on it sounds like it's way out on the timing. Either 90 or 180*. Not sure but if it is just puffing black smoke from the exhaust it sounds like it may be firing on the exhaust stroke.

Although I'm pretty sure it's not the case here's a little story of why everything needs to be checked. I was having a no start condition on the Subaru motor and just couldn't figure it out. Everything seemed just fine. That is until i pulled the rotor off and looked inside it. There were signs of friction. After a while I figured out that the rotor was binding on the cap intermittently and failing to turn. In my case it was a symptom of a larger problem, but I'm just saying leave no stone unturned. There isn't much that can be wrong, but some things can be a bit unexpected.

Sun Apr 22, 2012 5:11 pm

Is it possible for the timing to change with out moving the dizzy?

Sun Apr 22, 2012 5:18 pm

phantomlimb wrote: even tho we got a new coil?
Yes, the coil can't do it's job if it's not getting a good signal.

Sun Apr 22, 2012 5:18 pm

If you rotated the wires from where they started, yes.

Sun Apr 22, 2012 5:22 pm

If the points are adjusted the timing changes.

Also the order may be correct but have you physically checked that everything is in the right place at the right time? Ie the rotor pointing at the correct distributor cap electrode and in turn that lead going to the correct cylinder, and that the cylinder has both valves closed and the timing mark on the crank pulley is in the right place.

I know that sounds complicated but it isn't really. It's just making sure everything is roughly where it should be at the right time.

Because you are getting puffs the coil is fine, and the points are opening and closing (or do you have electronic points?). So everything is functioning in some form. It's just a matter of figuring out the why of when.
I know it sounds silly but did you put the cap on the right way round?

Sun Apr 22, 2012 5:22 pm

forgive me for being clueless , electronic modules? please explain to me what you mean.

and what wires are you talking about twisting?

Sun Apr 22, 2012 5:32 pm

phantomlimb wrote: forgive me for being clueless , electronic modules? please explain to me what you mean.
phantomlimb wrote: Distributor is petronix flamethrower..................
Pertronix is an electronic points replacement module.

Wildthings and Ratcamper wrote: If you rotated the wires from where they started...

Acted up before the cap change
phantomlimb wrote: Yesterday I tried starting, no dice..............Got new cap and rotor in mail (old ones were looking bad) and replaced.

Sun Apr 22, 2012 5:47 pm

busdaddy wrote: Wildthings and Ratcamper wrote: If you rotated the wires from where they started...

Acted up before the cap change

There is an old trick of opening the lid of a VW as you walk past and moving two or more of the wires around real quick. Maybe someone was reliving their youth.

Sun Apr 22, 2012 5:55 pm

I think what we did is put the wires on wrong once and botch up our timing. Its about time we got good at fixing timing anyway...

Thanks for all your help, guys!
We'll update after we fix it.

Sun Apr 22, 2012 8:45 pm

general rule of thumb - if it backfires one has spark so the coil reasonably Ok. Backfires are usually swapped wires, shorted wires, timing off or a really nasty fuel mixture problem. Glad you got the wires sorted out.

Mon Apr 23, 2012 11:10 am

we got her running!
thanks for the help everyone

Mon Apr 23, 2012 11:26 am

phantomlimb wrote: we got her running!
thanks for the help everyone

And ...

Aloha
tp