Tune problems?
Thread Starter
Teching In
Joined: Jun 2023
Posts: 1
Likes: 0
From: Indiana
Tune problems? I have a 99 4.8l in a 70 Chevy c10. I had the time done on a dyno back in 2016. Brought it home on a trailer, unloaded it, it wouldn’t start. Trouble shooted for a while, but pregnant wife was ready to go home, truck lived at my parents. Then life happened rapidly. My wife was 8 months pregnant and I was in my electrical apprenticeship. Yada yada, fast forward to 3 weeks ago, I went in the garage at my parents, charged the battery, primed the fuel lines, checked all the fluids… it started right up… following week I changed engine oil, filter, topped the other fluids off, it fired up, I putted around the neighborhood, then drove it 15 minutes home no issues…. Put fresh fuel in before leaving my parents. Now I put new tires on it last week, and it won’t start. I’m using a digital oil pressure gauge for a fuel press gauge, it’s up in the 70-80 psi, obviously too high, but can’t figure out why, and it smelled horribly rich when it ran but ran strong… it cranks very well sputters and coughs but won’t start.
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
I don't know the fuel system of your C10, but obviously its an LS1 swap and therefore has an electric fuel pump. Such fuel pumps easily put out 80 psi, but then have a pressure regulator which bleeds the excess pressure back to the fuel tank. The regulator can be either in the tank with the pump, near the pump when you have an external pump, or be in the engine compartment. The latter is called a "return system" as it used a return line from the engine compartment back to the tank.
Perhaps you already know all this, in which case it is just my attempt to bring this to the top for other/better advice.
Perhaps you already know all this, in which case it is just my attempt to bring this to the top for other/better advice.
