Headers lit my wiring on fire! Too rich? (MSL attached)
Posted: Wed Jul 11, 2012 8:52 pm
So I went out for a spirited drive today, with accel enrichment and EGO correction disabled to test out my VE table settings. I've got it idling around 1400 right now, because the idle gets suuuper lopey around 900 and I haven't quite worked out the idle settings to keep it from stalling out when the fan turns on or I load up the power steering pump. The car sounds great and pulls like crazy. Temps and oil pressure read fine while I'm driving, I'm not hearing any pinging, and in general it's starting to run really well.
Here's the problem: when I got home and pulled the car into the garage, I started seeing smoke from under the hood. I killed the engine and popped the hood and discovered that my wiring harness had melted and was on fire, which spread to my brake master cylinder. Luckily I keep an extinguisher in the garage and was able to put it out quickly... It looks like the driver's side header got so hot that it caused the wiring harness, a good 6-8 inches away, to melt. The plastic loom on the harness dripped onto the header and ignited.
I'm running 1 5/8" equal length shorty headers, but I never expected them to throw THIS much heat - can you guys take a look at my datalog and comment on my AFR's? We have E10 in NJ and I've been told that stoich should be 14.1:1. It seems to be right in the 13.8 range at idle, and the richest it went under acceleration was 11.8:1. There are a number of lean spikes correlated with throttle stabs due to accel enrichment being disabled. Is this too rich? Can too much timing cause this kind of heat? I advanced the timing a lot at low speeds to keep the engine from dying out under 900rpm. I don't think it's running with the timing retarded enough to dump the raw fuel into the headers, which I know can cause them to heat up at idle. I've heard too rich OR too lean can cause overheated headers. Am I good with the mixture, or should I lean it out? How much?
Here's the problem: when I got home and pulled the car into the garage, I started seeing smoke from under the hood. I killed the engine and popped the hood and discovered that my wiring harness had melted and was on fire, which spread to my brake master cylinder. Luckily I keep an extinguisher in the garage and was able to put it out quickly... It looks like the driver's side header got so hot that it caused the wiring harness, a good 6-8 inches away, to melt. The plastic loom on the harness dripped onto the header and ignited.
I'm running 1 5/8" equal length shorty headers, but I never expected them to throw THIS much heat - can you guys take a look at my datalog and comment on my AFR's? We have E10 in NJ and I've been told that stoich should be 14.1:1. It seems to be right in the 13.8 range at idle, and the richest it went under acceleration was 11.8:1. There are a number of lean spikes correlated with throttle stabs due to accel enrichment being disabled. Is this too rich? Can too much timing cause this kind of heat? I advanced the timing a lot at low speeds to keep the engine from dying out under 900rpm. I don't think it's running with the timing retarded enough to dump the raw fuel into the headers, which I know can cause them to heat up at idle. I've heard too rich OR too lean can cause overheated headers. Am I good with the mixture, or should I lean it out? How much?