Electrical issue (probable ground)

[Usudno]

Yesterday I dropped the roadster down for my first go cart. I have ran the motor probably 20 times since first start. Before dropping it down I zip tied any wires that might get in the way and torqued down the drive shaft. Once on the ground all it will do is crank. I pulled the plug wire off of the coil and I get one spark every 10-15 seconds of cranking!! No fire, or like I said very limited. Any ideas? I plan on going over my grounds again today. I'm running a blaster 2 coil and msd 6al

[walt mckenna]

If all you did was zip tie some wires before dropping the car down, then that's where the problem was created and that's where I would focus all my energy. The problem is almost never what you didn't do.

[Usudno]

Yep. I'll go through it this afternoon. Msd has a simple way to troubleshoot no spark by putting a jumper on the magnetic pickup plug and pulling the coil plug. I'll give it a shot.

[Usudno]

Just got off the phone with msd tech support. Ran a spark test on the magnetic pickup as well as the white wire I didn't use, something in the 6al isn't sending spark through the magnetic pickup. Heading to swap it out now and hopefully will go cart this evening.

[Jeff Kleiner]

Hmmm, MSD box quit? Never saw that one coming...

http://thefactoryfiveforum.com/showt...ight=duraspark

Sorry, but it was too easy Hope you get it resolved quickly.

Jeff

[Usudno]

I swapped boxes today. Go carted it and now I think I have lost spark again!! I didn't have time to test it thouroughly. I got the 6al at my engine builders recommendation. Is there an alternative to work with my msd pro billet distributor?

[Usudno]

I didn't lose spark this second time. I just panicked! Carb had flooded. My idle seems to be getting higher as it sits there. I'll play with t this afternoon and hopefully get it straight.

[Usudno]

I just started it back up and it was running rough. Gave it some throttle and it smoothed out a little but not quite right. I let it idle roughly for a few then it killed. Restarted it and it idled rough again and killed again. Now it won't start again! This is pretty frustrating. If someone has a recommendation for a ignition control module other than the MSD unit that will work with my distributor i'm all ears!

[bobl]

FAST HI6R would be a good unit. Daytona sensors makes a really sweet unit which would be the absolute best choice, but expensive. The FAST is around $300 and the Daytona is over $500. They are both very durable pieces. They both were original made by Crane. Then Daytona sensors acquired the marine version and improved on it. Apparently FAST acquired the race boxes. Crane still makes an HI6S But I don't think it will work with your MSD distributor. I quit using MSD products years ago. I've never had a failure with the Crane/Daytona sensors products.

[NAZ]

From the symptoms you listed above it sounds like you have an A/F mixture issue that may be the root cause and not the MSD box. I don't know of another CD ignition box compatible with the MSD distributer so you're looking at a significant investment if you decide to change out the MSD distributor for another system. Before changing the distributor I'd do some more troubleshooting. If you simply installed a carb out of the box without any serious attempt at tuning it then I'm even more suspicious you have a mixture problem. Yes you may have experienced an intermittent problem on a solid-state type ignition system but in my experience I usually find them failed hard (no spark) rather than "works sometimes but not always real good" kind of issues. Before spending that hard earned cash on a new ignition system take a systematic approach at troubleshooting the problem. Here are my three most likely things that may cause the rough running and stalling symptoms you described above: #1 incorrect mixture, #2 vacuum leak (causes incorrect mixture), #3 ignition timing. This is where I’d start. I'd take them in reverse order as the last two are easy to determine and you can check them off your list quickly. Once #2 & #3 are squared away, for the A/F mixture tuning you will concentrate on the idle circuit of the carb -- main jets, power valves (unless you're above 7,000' MSL then I might not discount this one yet), accelerator pumps, and squirters are not causing this issue. First check the float level to ensure it's correct. If you find it high you need to also ensure you have the correct fuel pressure for that carb. Regarding float level, high=rich & low=lean. Both rich and lean mixtures will cause rough running and it doesn't have to be real lean to stall at idle or just above especially with less timing lead. With the floats adjusted you need to set the idle mixture screws to get best idle quality or if you have an O2 sensor, to get the proper A/F mixture. If not constrained by emissions standards I shoot for ~13.0:1 to 13.5:1 A/F at idle and a bit richer just above idle with no load on the engine. For best idle you can trim the screws one at a time until you see a loss of RPM and then open them ½-turn or so and you'll be close but using an A/F meter and vacuum gauge is much more accurate. If you can't get the idle mixture adjusted right and you have idle feed restrictors (common on high end carbs like QuickFuel) you may need to change these up or down in size before you can trim the idle mixture and an O2 meter will tell you quickly which way to go. I like to use a tach, vacuum gauge, and O2 sensor when tuning carbs. It is much more accurate than the braille method (feel and sound) but in a pinch you can get real close without the fancy tools.

[Usudno]

Naz I appreciate the insight. The carb was "tuned" when it ran on the dyno. It has been removed once in order to drop the engine in. It was reinstalled and torqued down. I don't have much experience tuning carbs but have a good friend that is pretty good with them. I have a call into him as we speak.

[bobl]

I believe any ignition box capable of supporting magnetic pickup will work with the MSD pro billet distributor, which includes the ones I mentioned.

Bob

[GSides9]

One mistake I made was not flushing the fuel lines out before starting the engine. I've got fuel filters, but garbage still occasionally sticks in the needle and seat. This causes the bowl to overfill and flood the engine. My Quickfuel carb came with clear plugs so I just check them when the engine doesn't run right. Could be ethanol drying in the needle and seat too, regardless. I just take it out, wash it out with carb cleaner and reinstall. Be ready to adjust the float level. Hopefully this will end once it is on the road. I've cleaned it about 6 times so far.