Operation Lipstick on a Pig

[fleming442]

Took it for a road test today: all seems to be good with the new pump. I warmed it up to operating temp, then took it around the block for 5mi with a few WOT pulls. Seems good so far; I'm good as long as the AC compressor holds together (related thread in General).

For those paying attention: I had started with a GN pump, but swapped it for the Firebird pump while I was chasing the VATS issue. They are different part numbers with the difference being the bypass valve next to the inlet. Both seem to work with my Frankenstein application.

 

[Clutch]

Took it for a road test today: all seems to be good with the new pump. I warmed it up to operating temp, then took it around the block for 5mi with a few WOT pulls. Seems good so far; I'm good as long as the AC compressor holds together (related thread in General).

For those paying attention: I had started with a GN pump, but swapped it for the Firebird pump while I was chasing the VATS issue. They are different part numembers with the difference being the bypass valve next to the inlet. Both seem to work with my Frankenstein application.

Needs an intercooler

 

[Turbolq4]

Needs an intercooler

And associated hardware

 

[fleming442]

Hmmmm, first commute drive didn't go so well. I took TURNA's suggestion of opening up the vent holes in the fuel fill neck, which works GREAT! However, it worked to good. It cured my slow fill situation, and I could finally put the pump on full blast without splash back, but it also allowed me to jam 18 gallons in it which the car DOES NOT LIKE AT ALL. It died at the stop sign in front of the gas station, on the exit ramp to the highway, and sputtered halfway down the road. Basically, the fuel blocks the vent and hydrolocks the system. Great, just great. 😒

 

[TURNA]

You should know better than to listen to me!!!

 

[DRIVEN]

Basically, the fuel blocks the vent and hydrolocks the system. Great, just great. 😒

That's not a concept I've seen or heard of before. How did you come to this conclusion?

 

[fleming442]

That's not a concept I've seen or heard of before. How did you come to this conclusion?

Well, if you look at a GN sender, the vent is all the way at the top with just a cup underneath. I ran the line straight to the EVAP solenoid on the intake. That EVAP valve may or not be open- I honestly don't know much about it other than it opens on initial start up to compare pressure against the tank pressure sensor (that I don't have). It's been doing it since I built the car, and putting more fuel in it exacerbated the problem. It's the only thing I could come up with. Once some of the fuel burns off, it's fine until it gets low, at which point, fuel slosh becomes another issue. I think, short term, I'm just going to install a Tee in the line, open to atmosphere, and the EVAP solenoid will probably end up creating a vacuum leak for itself when it cycles. I have been brain-F-ing it all morning. Ultimately, I think I need to get the charcoal canister, tank pressure sensor, and fresh air purge off a 4th gen F-body to wire/plumb in. That means cutting a hole in the floor of a PnP car, cuz I ain't trying to drop the tank.......maybe? 🤔 Any ideas?

 

[DRIVEN]

Purge solenoid is normally closed so if you just unplug it you'll no longer have a direct path for raw fuel to get to the intake. If that wasn't deleted in the tune, you'll probably set an open circuit code for the purge sol.
If garage fumes are what you're battling, you could just run your tank vent hose to the Gbody canister and run the other port to the intake elbow, making it a basic early style system. Canister could be placed anywhere as long as its higher than the tank to avoid siphoning when it's really full.

 

[fleming442]

No, I'm not concerned about the fumes...... yet. I put my airbox where the canister would go and threw it away, so I need to come up with something. I can't put my finger on it, but it dies when the fuel sloshes on a very full tank.
Another scenario I came up with is that it doesn't have enough pressure on the return side and the fuel is pushing back against the return enough to stop the flow? I'm really lost on this one.

 

[Clutch]

No, I'm not concerned about the fumes...... yet. I put my airbox where the canister would go and threw it away, so I need to come up with something. I can't put my finger on it, but it dies when the fuel sloshes on a very full tank.
Another scenario I came up with is that it doesn't have enough pressure on the return side and the fuel is pushing back against the return enough to stop the flow? I'm really lost on this one.

i think the pig said