I'll set the stage for my problem. Engine is a stroker 475 with about 4000 miles on it. Plugs and carb are the same as was dyno'd with two years ago. Been running fine. starts fine, cruises fine, turns low 12s at 110+. So, I stopped for gas yesterday at my favorite station that has 93 non-ethanol and pumped 10 gallons to full. Left the station and about 1/4 mile down the road went to make a left turn and the engine stalled and would not restart. Let it sit for about 5 minutes and it barely started but would not idle. I was able to get it into gear and limp home which was less than a mile. So, here's what I've done so far. I'm able to keep the motor running by raising the idle way up to about 1000 rpm but it's barely running and missing badly at any rpm. Timing is good, hasn't changed (25 static @ idle, 35 deg @ 3000 rpm) same as dyno setup. Vacuum is good about 14-15 hg Fuel pressure is good from my RobbMC pump at about 8 psi Coil voltage with motor running is about 8 volts Coil resistance is 3.5 ohms. So, how do these NGK Fr5 plugs ( I have TA Aluminum Stage 1 heads) get this rich/fouled? They are all gapped .038 - .040. My ignition is the Lectric Limited single wire conversion into a stock coil which is how the motor was dyno'd and has been fine all along. I honestly can't say of they have been this fouled all along or just when the problem occurred yesterday. The carb is a Fred Catlin QJ checked out by both Robb Ross and Jim Weise. I put my timing light pickup on each of the 8 plug wires and they all show the same RPM so they should be good. So, where do I go from here. I hate to just shotgun parts without some reasoning.
Bad batch of fuel? Only way to know is out with the old, in with the new (from a different source). $0.02, Devon
Thats fuel or oil. How does the carb look? Is the lid soaked with fuel? I'm also wondering how strong the spark is. Electric limited has a sub-par reputation. I'd bet a cold beer that the spark is weak. You got enough to run but its only burning half the fuel.
Lectric Limited single wire conversion,, isn't that a HEI type pointless ignition,,,,, If so shouldn't 12vt +......
Likely bad gas, the left turn thing is a classic indication of a needle/seat issue in the carb. Maybe the needle is stuck open due to to a bit of debris, so that carb can't stop the fuel from flowing in. Over rich?
Ray, are you using the same ignition system that was used on the dyno when Jim had it? Do you run a return? If not, try it and see if it fixes or improves your condition.
Yes, it has the exact same Lectric Limited conversion it was dyno'd and run low 12s with and the pump has the 1/4" return back to the tank. In addition, about 6 months ago I upgraded the fuel system and ran 1/2 " line from the tank all the way to the RobbMC fuel pump with all 8AN fittings. I also added a RobbMC large fuel filter under the driver's door also with 8AN fittings. It's been running fine with that for a few months. My next try will be to disconnect the fuel line at the fuel pump and run a line from the pump input to a can of known good 93 octane gas to see if, maybe, I got some bad fuel from the station I go to for all my non-ethanol gas. Since the problem started just 1/4 mile from the station it's possible. I'll change the plugs before I do that. While I'm at it, as long as I'm buying new plugs should I continue with the NGK FR5 (7373) I have now? Or, maybe go colder? My motor has 10.5 static compression, TA Stage 1 Aluminums, and runs about 180 deg. around town. (sometimes as much as 190-195 in stop and go with the A/C on in 90+ degree weather)
I had a similar issue ran great for about 500 miles, then wouldn’t start. Plugs were coated with soot, I put in a hotter plug and bump the timing up a few degrees, been running great
I would check to see if the plug wire can shoot sparks, or should i say lightning bolts. lol When I had trouble with the coil I had a very hard time starting the car and would run. I ended up changing the coil and when I checked it against the old one the new one was sending lightning bolts 1/2 inch and the old coil would shoot a spark but not very strong, which would make you think the system is ok but it wasn't, not after the new coil was shooting lightning bolts. But I would try some other gas if you did not buy too much maybe stick that gas in the tractor? I like the idea of checking that gas first since it was the last place you were at before trouble. Well I guess when you start it back up with different gas you will be able to look in the carb and see if the venturies are leaking gas out while it is running then you would probably say that the float is sticking
I do have as spare coil. First thing I’ll do is disconnect the fuel line and run some fresh gas in after replacing the plugs.
If it has been running fine and all of a sudden it starts running like crap, I ain't going hunting for zebras.. I would get a gas can, fresh, good gas (non-ethinol) purge pump, line and carb, stick in new plugs and go romp on it. You'll know in short order if it is gas or not.
I would take a step back… and as mentioned above, do one thing at a time. How long has it been since you looked at the plugs? Put new plugs in and try it. If she runs good, the keep an eye on the plugs and you may need a hotter plug in the future or a jetting change. Still like crap? Then try the separate gas can…
Ray I believe it’s spark, coil shows bad after it gets hot, or it’s the ignition, but most certainly a spark problem nothing else.
