Voeltagear
Well-Known Member
What ignition are you running? I'm considering a GM HEI module. I've had good luck with it b4.
Light throttle ping from stoplight on hot days
- Thread starter Voeltagear
- Start date
Proform/Mopar distributor, Mancini racing ignition module, MSD Blaster II coil, .8ohm MSD resistor, 8mm MSD plug wires. The ProForm ignition kit was already on the car when I bought it, just spiced it up with the Mancini and MSD stuff. Aside burning out a coil from mounting it improperly (don’t mount Blaster II coils horizontal) it’s been great. Car starts first crank year round hot or cold.
I’ve also considered the GM HEI and ready run dizzies but, for now just sticking to what’s one there till it burns up.
Voeltagear
Well-Known Member
A good ignition system can compensate for AF issues too. I had 9.5:1 360 that I removed the choke. It started right up except in the coldest of weather below 0°f. Cold blooded as hell but it always started.
Voeltagear
Well-Known Member
I'd be afraid of sucking in birds!
Aspen500
Well-Known Member
A quart of oil in 1,200 miles isn't terrible but it COULD contribute to pinging, especially if the engine is on the verge of pinging anyway.
Without a borescope it's hard to know but, a possibility also could be carbon build up on the pistons and chambers. You could try running a can of Sea Foam or equivelant combustion chamber cleaner through it to see if it helps.
Without a borescope it's hard to know but, a possibility also could be carbon build up on the pistons and chambers. You could try running a can of Sea Foam or equivelant combustion chamber cleaner through it to see if it helps.
Voeltagear
Well-Known Member
I've run B12 chemtool through 2 tanks. It helped a lot. It had colder plugs when I got it, probably to help with the pinging. They had some deposits on them. The carb was also plugged up so bad it wouldn't idle.
Voeltagear
Well-Known Member
I found something called Ethanol Defense. Supposed to protect the carb from corrosion and improve fuel performance. Upper cylinder lube and clean deposits. Maybe worth a try.
What do the plugs look like? Could have carbon deposits causing hot spots. Get the motor up to temp, turn the idle screw up to 1k rpm, and use a spritzer bottle of water to spray a mist of water down the throat of the carb. Just a bit to steam clean the pistons. Don't overdo it.
Voeltagear
Well-Known Member
Plugs are new. Less than 1000 miles. I'll check condition this week. It really seems like a situation that could be corrected with the EGR being reinstalled. Or higher octane, less timing, more fuel, etc... 100% stock other than the EGR delete. It's currently operating outside of the design parameters which means adjustments to the remaining components would be required.
Voeltagear
Well-Known Member
this is one of the plugs with deposits on it. Cylinder 5 and 6 have the most. But not bad at all.
I wouldn’t imagine the EGR delete would cause a lean condition itself. It shouldn’t have had THAT big an effect on cylinder temps or just have an effect off idle to part throttle but, I don’t know if the Spark Control/Lean Burn might be doing something funny to compensate for it being disconnected. I have no experience with them. It still sounds like a metering rod/spring/jetting issue to me.
My car had a Carter 2v, the Lean Burn delete done and EGR was failed shut/blocked by the time I got my hands on it. It drove great after a timing and carb idle/air speed adjustment. I’d still start at the carb myself. Get your wide band plumed in; heck just use one of those clamp/gasketed bungs for now. Make sure fuel/air/vacuum are all right before diving into the engine.
Cheers everyone.
My car had a Carter 2v, the Lean Burn delete done and EGR was failed shut/blocked by the time I got my hands on it. It drove great after a timing and carb idle/air speed adjustment. I’d still start at the carb myself. Get your wide band plumed in; heck just use one of those clamp/gasketed bungs for now. Make sure fuel/air/vacuum are all right before diving into the engine.
Cheers everyone.
Was 1976 too early for Lean Burn guys? If this thing had it from the factory then that isn't a factory carb and distributor. The LB distributors were locked out with no mechanical or vacuum advance.
Your initial timing seems very low, even for a factory cam'd motor. I would be starting from scratch with this as there are too many unknowns. Do you know anyone with an LM2 or some setup for measuring AFR? Does the car have manifolds on it with provisions for an o2 sensor?
Your initial timing seems very low, even for a factory cam'd motor. I would be starting from scratch with this as there are too many unknowns. Do you know anyone with an LM2 or some setup for measuring AFR? Does the car have manifolds on it with provisions for an o2 sensor?
Voeltagear
Well-Known Member
Not a lean burn. I do have a wideband. Need to add a bung.
Voeltagear
Well-Known Member
XfbodyX
Well-Known Member
You might consider laying out all 8 plugs to read them all. The center two cylinders always burn hotter then the ends. If your plugs show this you can consider running one range on the 4 corners and another on the inner 4 cylinders.
