no spark - '79

[Weelan]

Hey all, I'm finishing up installing my new engine, and I have fuel now, but not getting spark.

I read several threads and tried a few things. I used an inline spark tester and it doesn't light up. I checked the voltage at the coil and I had 11.7v. Not 12v. I was turning over fine, but wouldn't spark. I read some things saying that you can connect the coil backwards and it would decrease the voltage/spark 50%. I can't tell personally what color the wires are to be honest. One is striped and one is kinda white. I asked my non-colorblind wife to look and she said the striped one is kinda black/brown, and the white looking one is really faded red. I checked the voltage of the wires themselves and the faded red shows 11.7v. I plugged that in to the positive of the coil and tried to start the engine and it wouldn't turn over.

I may have ruined the ignition module by swapping the wires? I switched the coils back and the engine still wont turn over.

[bradartigue]

Pink = + (on the coil it usually says +B)
The other wire = - (negative)

Take the coil wire off at the distributor and hold it about 5mm from the cylinder head while someone is cranking the engine. If you have spark there then the problem isn't the control module.

Most common issue with new engine builds is people orient the distributor to fire the #1 cylinder at TDC. The shop manual has horribly ambiguous language around this. The correct procedure is for the rotor to point at #4 when the #1 cylinder is at TDC, so that #4 is just about to fire. When #1 is at TDC both camshaft timing holes are aligned with their markers.

I'm almost laughing as I write this because I can't get a 79 to fire right now no matter what we do, so we're replacing plugs and wires just because hell, it has to be the plugs and wires, everything else works. I actually think the plugs are fouled beyond repair (they won't spark when grounded, they will spark when held just off the head)...never had this happen before so I'm stymied...

[Weelan]

Thanks brad. I'll make sure they're on that. I need to find the documentation on the module I have to make sure red (+) goes to B on that. I believe my timing is correct. I made very sure of reading a lot of the posts about that because I was pretty nervous not to mess things up.

The only things not new on the engine related to spark are the wires and cap. But the other problem there is that so many things are changed it's hard to know. There aren't a lot of components to the 79. As far as my knowledge goes anyway.

I have been watching your blog and thread about that 79. Good luck!

[Weelan]

Oh, I wonder if I flooded the cylinders and the hydrolocked? Does that make sense why it would stop being able to turn over?

[bradartigue]

Oh, I wonder if I flooded the cylinders and the hydrolocked? Does that make sense why it would stop being able to turn over?

I doubt it. Take a plug and shine a light in there, I doubt it is hydrolocked. More likely just out of time or your plugs are carbon fouled.

[Weelan]

I guess I need to recheck the timing. Maybe it jumped out of time while trying to crank it? Is that possible?

I'll pull the plugs and see if they're fouled too.

[majicwrench]

Not sure if Brad heard the key phrase "stop being able to turn over " that is bad. Obviously fouled plugs aint gonna do that. Yes you need to recheck cam timing and aux pulley. Sure pull plugs to make sure not hydrolocked, it is possible locked from fuel OR water. Goodluck

[bradartigue]

Not sure if Brad heard the key phrase "stop being able to turn over " that is bad. Obviously fouled plugs aint gonna do that. Yes you need to recheck cam timing and aux pulley. Sure pull plugs to make sure not hydrolocked, it is possible locked from fuel OR water. Goodluck

Yeah I missed that - stopping screams aux pulley...

[Weelan]

Well, it looks like I had the coil wires backward. They were really faded and I'm colorblind enough that I didn't get it right. Got that correct, and I rotated the engine back around to have the timing marks all lined up. I kind of think the starter may have been packed up. Is there a way to check the aux pulley? Like does it have timing marks like the other pulleys?

When I got the timing marks lined up, the distributor was about 10-15 degrees behind being lined up for 10degrees btdc. I lined that back up, charged the battery a bit more since the lights were a bit dim, and gave it a crank and it started right up.

http://s1062.photobucket.com/user/Weela ... 3.mp4.html

If you listen closely, there's a high pitch sound that sounds like something electrical or something, I'm not sure what it is. I haven't finished setting timing, so i'll investigate more to try to find that noise. It doesn't seem like it should be there.

[majicwrench]

My computer doesn't do a very good w sound, so I could just barely listen, and can't really hear anything. CONGRATS on getting it running. Aux pulley has got to be in pretty much the right position or it won't roll over. Obviously, it is rolling over, don't worry about aux at this point.
Keith

[Weelan]

Thanks! I won't worry about that then.