Cutout issues, High Timing?
Thread Starter
Teching In
Joined: Feb 2012
Posts: 4
Likes: 0
Cutout issues, High Timing? Car Background:
I have a 68 Chevelle with a 98 Camaro LS1. There are no mods on the engine. I have a tune from XP racing in OKC on it right now. The rear O2s have been deleted. The fuel system uses the original fuel sending unit with a racetronix pump.
The Issue:
The car has a very intermittent problem. It usually occurs in the morning on the way to work and will go away when I head out for lunch. I get a strange cutout in power at 65-75mph. It feels as though I am having short bursts of fuel starvation. If I go WOT when it cutouts it will usually push right though the cutout and accelerate.
Parts I have Replaced:
First I had the tuner verify the tune. He said there are no issues but he didn't ride with me and didn't get to see what it does at high speeds. I have replaced an O2 sensor and swapped it to both sides. I have also replaced plugs, the IAT sensor, and ECT sensor. The MAF has been cleaned three times and I have run both Techron and Seafoam through the tank. I also drove around with a fuel pressure gauge for a day. At idle the pressure sits about 58-60 and doesn't change. I did see a slight and brief spike of about 3psi (60-64) when the car cutout.
Wrap-up:
I am going crazy trying to track down the issue. I bought a wifi adapter for the ODB2 port and downloaded an app to my iphone to watch what the engine is doing. The O2 sensors seem to switch fine from .900ish max down to .000 almost. However, the timing advance seems very high. At WOT it pegs around 41 and at idle in Park it sits around 17 or 18. While cruising at around 70 and most freeway speeds it is always between 34-38. I took a screenshot with my phone of the parameters at given times on my last drive home.
Sorry for the huge post! I wanted to be as specific as I can. I know there are some real ls1 geniuses that float around these boards and appreciate any insight anyone can provide.
I have a 68 Chevelle with a 98 Camaro LS1. There are no mods on the engine. I have a tune from XP racing in OKC on it right now. The rear O2s have been deleted. The fuel system uses the original fuel sending unit with a racetronix pump.
The Issue:
The car has a very intermittent problem. It usually occurs in the morning on the way to work and will go away when I head out for lunch. I get a strange cutout in power at 65-75mph. It feels as though I am having short bursts of fuel starvation. If I go WOT when it cutouts it will usually push right though the cutout and accelerate.
Parts I have Replaced:
First I had the tuner verify the tune. He said there are no issues but he didn't ride with me and didn't get to see what it does at high speeds. I have replaced an O2 sensor and swapped it to both sides. I have also replaced plugs, the IAT sensor, and ECT sensor. The MAF has been cleaned three times and I have run both Techron and Seafoam through the tank. I also drove around with a fuel pressure gauge for a day. At idle the pressure sits about 58-60 and doesn't change. I did see a slight and brief spike of about 3psi (60-64) when the car cutout.
Wrap-up:
I am going crazy trying to track down the issue. I bought a wifi adapter for the ODB2 port and downloaded an app to my iphone to watch what the engine is doing. The O2 sensors seem to switch fine from .900ish max down to .000 almost. However, the timing advance seems very high. At WOT it pegs around 41 and at idle in Park it sits around 17 or 18. While cruising at around 70 and most freeway speeds it is always between 34-38. I took a screenshot with my phone of the parameters at given times on my last drive home.
Sorry for the huge post! I wanted to be as specific as I can. I know there are some real ls1 geniuses that float around these boards and appreciate any insight anyone can provide.
