Ignition trouble

**wheeliE-maxx** · 12-02-2009, 02:58 PM

What are some causes for what seems to be a dropped spark that I could check? I've had fouled plugs before, that will constantly make the "spitting" sound and run like crap. But this is random and it seems like the misfiring cylinder (on the left) doesn't have any spark when it happens. I took out the tach wire just in case that could be a problem to no avail. All the plugs have been pulled and are clean. This is an HEI with an Accel super coil and their performance module, super stock wires (none of which are burnt), brand new #6630 NGK 4-heat range (ngk is the oppsoite on heat ranges, like a Delco r45ts) v-power plugs. New msd cap and rotor. Any help is very appreciated. Hearing it misfire makes me sick to my stomach, can't stand an engine not running right. This is a first gen sbc 350 by the way

**0rion** · 12-02-2009, 05:34 PM

have you watched spark and narrowed it to 1 cylinder? The reason I ask is you reference the cylinder that isn't firing...is there only 1 not firing?

**wheeliE-maxx** · 12-02-2009, 05:58 PM

hell no, just figured out it's all over. clean plugs, new everything... Asked on nastyz28.com (2nd gen forum, my sbc go to) and got alot of responses about how hard cheap Accel wires blow when it comes to spark leak. If I had a spray bottle they said to spray around the wires at night. If they're "leaking" it will obviously show. I'll try to find one and do it tomorrow

**0rion** · 12-02-2009, 06:02 PM

I tell you who knows these first gen engines inside and out is firebirdjones. Send him a PM and I guarantee he'll be able to give you some guidance.

**Smittro** · 12-02-2009, 06:47 PM

Put your old High Energy Ignition coil back on and see if there's a difference in how it runs.. I mentioned this in another thread, but if your mileage is getting extreme, the cam maybe losing a lobe/s. Very common in the old SBC's.. Especially in the smoggers it seemed..

**wheeliE-maxx** · 12-02-2009, 06:50 PM

Huh? the super coil is on it now. This is a random misfire on lots of different cylinders. I believe now it HAS to be the wires. Ran great (other than drinking water and oil) before my intake and gasket swap. Cam is fine, it's the same as the 300/327 cam. Not a smogger, not flat

**Smittro** · 12-02-2009, 07:10 PM

Originally Posted by wheeliE-maxx

Huh? the super coil is on it now. This is a random misfire on lots of different cylinders. I believe now it HAS to be the wires. Ran great (other than drinking water and oil) before my intake and gasket swap. Cam is fine, it's the same as the 300/327 cam. Not a smogger, not flat

My bad I was thinking stock.. But ya try putting your old coil back on to see if the misfire goes away.

Check the power to the coil wire. May sound crazy but I've seen the coil pwer wire become corroded under the actual insulation and begin to cause intermitant under power to the coil.. Check your grounds too. Not knowing what your truck looks like under the hood hinders me somewhat on the diagnosis. But I'm leaning more towards an issue with the coils power source.. I dunno.. Also I'm old school, I'd need to hear it running. I can usually tell what's going on on the old chevy motors just by simply listening to it.. Yeah I am that good.. lol pats self on back..

**wheeliE-maxx** · 12-02-2009, 07:22 PM

Yep, i've gotten pretty good by ear

I wish I didn't have to be but... This isn't a misfire, i've had that. Fouled plugs yada yada. This is a random NO fire on some cylinders. Could be every couple seconds or minutes, just random. And I can tell that when it is firing on all eight one cylinder isn't just taking a free ride, like say with a fouled plug. I might have Friday off because people freak out when a few snow flakes fall. So i'll try to pull it all apart. No arcing under the cap or rotor. The coil and all is new, no corrosion. As is the ignition wire.

**Smittro** · 12-02-2009, 07:37 PM

I'm not overly familier with the Excel coils but it maybe that the HES sensor is taking a sh*t on you..

**wheeliE-maxx** · 12-02-2009, 09:33 PM

HES sensor? wut?

**Smittro** · 12-02-2009, 09:48 PM

Originally Posted by wheeliE-maxx

HES sensor? wut?

Hall Effect Sensor. It the peice of electronics in the base of the dist. housing that uses a magnetic field pickup to trigger spark ignition.

**wheeliE-maxx** · 12-13-2009, 06:28 PM

Originally Posted by Smittro

Hall Effect Sensor. It the peice of electronics in the base of the dist. housing that uses a magnetic field pickup to trigger spark ignition.

Hey Smittro, were you talking about that round dealy-bob shown here in this pic?

I replaced the accel module with a spare new one I had, seemed a little better as far as the severity and frequency of the miss, but still did. The whole thing is oily on the inside I guess from when oil was on top of my old manifold and blown everywhere. But i'm slapping an ebay hei in there, all new components, no more fiddling with old worn out junk. http://cgi.ebay.com/ebaymotors/SBC-B...Q5fAccessories clear cap, internal coil. I had a clear cap once and it looks cool as well as lets you see if it's firing. Lifetime warranty.. Or should I go with this http://cgi.ebay.com/ebaymotors/CHEVY...Q5fAccessories Small base, external coil. My firewall is NOT meant for hei for sure, no room.

**pajeff02** · 12-13-2009, 06:35 PM

It's night time. Start the engine and turn out the lights -- see if you have any spark jumping around. You can also resistance test your ignition wires to see if you have anything strange going on. Or, just swap your old wires back on (if you still have them) to see if there is any difference. Other than that, Smittro has it covered.

**wheeliE-maxx** · 12-13-2009, 06:44 PM

Yep, will do tomorrow night. I plan on custom fitting some NICE new wires, not guessing as to which cylinder these crap accel super stocks go to. Along with the new distributer...

**Smittro** · 12-13-2009, 09:47 PM

Originally Posted by wheeliE-maxx

Hey Smittro, were you talking about that round dealy-bob shown here in this pic?

I replaced the accel module with a spare new one I had, seemed a little better as far as the severity and frequency of the miss, but still did. The whole thing is oily on the inside I guess from when oil was on top of my old manifold and blown everywhere. But i'm slapping an ebay hei in there, all new components, no more fiddling with old worn out junk. http://cgi.ebay.com/ebaymotors/SBC-B...Q5fAccessories clear cap, internal coil. I had a clear cap once and it looks cool as well as lets you see if it's firing. Lifetime warranty.. Or should I go with this http://cgi.ebay.com/ebaymotors/CHEVY...Q5fAccessories Small base, external coil. My firewall is NOT meant for hei for sure, no room.

The hall Effect sensor is that black thing with the tiny bolts going through the brass collared holes in it.. I think they're 1/4in. bolts or some shtuff it's been awhile but that's the sensor. They're not expensive I'd just grab a Hall kit and replace it all.. Can't hurt..

**Smittro** · 12-13-2009, 09:50 PM

Oh and take that Eccel coil and throw it off an effin' wall! That's about how usefull it is..

**wheeliE-maxx** · 12-14-2009, 12:10 AM

Uh, wut? If the thing you are referring to is also known as an ignition module, then yes. In the foreground of the pic, black plastic with the brass collars. That's my new stock replacement one, took of the accel "high performance" one. I am not at all impressed with accel, never had a problem with msd. I had msd 8.5 wires on my last truck, they could lay on a manifold or header shortly and not burn. But an accel 8.8 with about and 1/8th inch clearance burned like hell. Couldn't find replacements so had to go to the cheap superstocks. They burn like paper. Got a few of the old 8.8's subbed in because of that. That's not the cause of the problem of course, did it before with all super stock wires.. And yes, the coil is useless. I hate it hanging over the wire ends, sucks getting them out with it on. Also sucks to screw the sum bitch down. I tried to find an Accel brute thunder (more powerful and actually IN the cap) but couldn't, I was replacing most of the parts at the time tracking down a problem. Didn't want the old bad part frying a new one. I've also shocked myself touching the top plastic on there, never happened before when touching the cover of an in cap one...