I have a LT1 swap here that is suddenly behaving very strangely. The engine is from a 1995 Camaro and has little done to it. No internal stuff, just Venom injectors(I know junk), Cold air intake, and true dual exhaust with h-pipe and cats. Has a brand new MSD Opti and MSD coil. Same old ignition module. It is in a 1983 Chevy Malibu and has a Street and Performance wiring harness that is brand new. It has started perfectly fine for quite some time now. Then a few days ago things suddenly changed.
While doing some tuning the other day and noting some fairly cold cylinders we decided to do a compression test. I pulled the fuel pump relay and all of the fuses in the engine harness(not marked which is the Fuel pump so just played it safe). Compression test was fine, so I put it back together and fired it up. The next morning first thing I came in and loaded a new file I had worked on the night prior(very minor timing and fuel changes). When I went to start it the car cranked and cranked. I was concerned my flash was corrupted so I tried to read it. Read fine. Reloaded the previous file to my changes. Still wouldn't fire up. Finally after cranking it for far longer than I like, playing with the throttle a bit, it fired up. When it is not wanting to start, as you roll off of the key you get a few diesely pops out of it and it pushes a tiny bit of smoke out of the intake. When it does finally fire up, it runs like a top. Perfectly fine. Took it out on the street and feels great.
If you let it sit for a few hours, or overnight, it becomes a hard starter again. Fuel pressure comes right up with one key cycle. It only comes up to 40psi KOEO. And about 35 psi idling. So I don't care for that a whole lot, though it is JUST below the spec.
I have spark and injector driver pulses a noid light when it is cranking and not seeming to fire. So honestly this make very little sense. VATS is deleted out of the tune and the Street and Performance harness has a VATS bypass module so even if it wasn't it would still run.
The only things I can think right now is I am getting a bad signal from the Opti for some very strange reason making timing of all events off. Or I am not getting nearly enough fuel volume. However why would it run well once it gets going if either of those was the case? The fuel pump is a brand new in tank unit, I am unaware of what pump it is.
Does anyone have any idea? The only way I can get it to go initially is to just crank and crank and crank on it. Datamaster is showing RPM during cranking as well.
While doing some tuning the other day and noting some fairly cold cylinders we decided to do a compression test. I pulled the fuel pump relay and all of the fuses in the engine harness(not marked which is the Fuel pump so just played it safe). Compression test was fine, so I put it back together and fired it up. The next morning first thing I came in and loaded a new file I had worked on the night prior(very minor timing and fuel changes). When I went to start it the car cranked and cranked. I was concerned my flash was corrupted so I tried to read it. Read fine. Reloaded the previous file to my changes. Still wouldn't fire up. Finally after cranking it for far longer than I like, playing with the throttle a bit, it fired up. When it is not wanting to start, as you roll off of the key you get a few diesely pops out of it and it pushes a tiny bit of smoke out of the intake. When it does finally fire up, it runs like a top. Perfectly fine. Took it out on the street and feels great.
If you let it sit for a few hours, or overnight, it becomes a hard starter again. Fuel pressure comes right up with one key cycle. It only comes up to 40psi KOEO. And about 35 psi idling. So I don't care for that a whole lot, though it is JUST below the spec.
I have spark and injector driver pulses a noid light when it is cranking and not seeming to fire. So honestly this make very little sense. VATS is deleted out of the tune and the Street and Performance harness has a VATS bypass module so even if it wasn't it would still run.
The only things I can think right now is I am getting a bad signal from the Opti for some very strange reason making timing of all events off. Or I am not getting nearly enough fuel volume. However why would it run well once it gets going if either of those was the case? The fuel pump is a brand new in tank unit, I am unaware of what pump it is.
Does anyone have any idea? The only way I can get it to go initially is to just crank and crank and crank on it. Datamaster is showing RPM during cranking as well.