Help....fuel starvation?

[catmanzr]

Help...... Got my nova on the the road today and ran into a problem. It's a LSA with a gm computer (e67) gm wire harness and a Vaporworx controller with a cts-v pump.

I ran the car up and down my road (about 4 miles) and it ran great. Accelerated hard and overall very good.

I let it sit in my driveway about 5 minutes and went to move it back in my shop. It seemed to crank a little long but fired up.

I went to take it back down the road an hour later. It started normal. I took off and about 1/4 mile it kinda hesitated. I accelerated harder and it just died. I pulled into a driveway and looked things over and couldn't find any thing. It started and as soon as I accelerated it would die. Did this three times. It would basically idle, but when I would try to accelerated it would die.

Also, I had to wait a couple of times because I wouldn't hear the fuel pump kick on after it died.

Any ideas? It ran great an hour before but then just acts like its simply running out of gas.

I had about 6-7 gallons in it. I put a fuel pressure gage back on it in the garage immediately and it was at 60 psi at idle. If I would wack the gas it would drop to 57-58psi momentarily.

Any ideas? I'm lost.

[Che70velle]

Sounds like a fuel issue. 5-6 gallons should be plenty of fuel to run car properly, especially with the Vaporworks system. What tank are you running? How did you vent the tank? Are you sure the vent is operational?

[catmanzr]

It's a ricks tank with corner pick up. I've read you can run them pretty low. The vent is built into the tank. You just screw in a 1/4 pipe fitting and route a hose.

I'm baffled that it ran great an hour before, then acts like it running out of gas. I'll put some more fuel in tomorrow, but I don't think that's the problem.

[Che70velle]

No, with the Vaporworks setup, your probably fine on fuel, unless it's literally just about empty. If you've got a couple gallons in it, your fuel level is not the problem. I was just curious about your vent setup, as it kinda sounded like the vent wasn't functioning properly.

[CarlC]

Any chance you can drive the car and observe the fuel pressure? If the pressure stays high but engine stumbles/dies, it's not a pump/controller issue. Blipping the throttle in the driveway puts very little load/fuel demand on the engine.

Hot start can often be a challenge from a tuning standpoint. You may want to leave the fuel pressure gauge on the fuel rail after engine shutdown to see if the fuel pressure maintains. If not, and there are no external leaks, then either the fuel module or injectors are leaking. It's not uncommon for some aftermarket injectors to drip, hence the fuel system loosing pressure after key-off.

There are several reasons that you may not hear the pump turn on with just key-on. First, if the engine was recently shut down the fuel pressure has spiked. During engine shutdown/key-off, the injectors shut but the pump still spins due to inertia, hence the pressure spike. If the VaporWorx controller senses this high pressure, it won't turn on the pump. The other is that if the ECM goes through several key-on cycles without engine rotation it kills the fuel circuit. After a pre-set time and/or engine rotation, the fuel system will trigger.

I sent an email a few minutes ago. We can discuss some other options for testing but it's much easier on the phone.

[catmanzr]

On the initial start ups I left the fuel pressure gauge on. When idling I adjusted to 60psi. After shutoff It actually rose to 70 psi and held pressure for a long time.

I will mount the gauge to the windshield today. You are right that it acted different under load.

What really has me scratching my head is how good it ran and then an hour later kept dieing.

It literally just acts like its running out of fuel.

Thanks for the email Carl. I look forward to talking to you.

[Vince@Meanstreets]

Put more fuel in it while your at it.

[catmanzr]

We'll I mounted a fuel pressure gauge to the windshield and volt meter to the vaporworx controller. Everything on the fuel side did what Carl told me it would. I don't think it's fuel related.

The car did not stall today like it did yesterday driving down the road. It did stall once pulling into my driveway but started right up.

Still not 100% sure whats going on.

Thanks to Carl for the phone call today. Awesome customer service!

[CarlC]

Thanks for taking the time to diagnose. It's good that the fuel delivery side is working, but that stubborn unknown.....

[MaxHarvard]

Sounds almost like a bad coil pack or timing issue... Definitely odd if your fuel pressure is good.