Hey All, it's been a minute since I've stalked the rx7club. Like... probably 10 years.

Anywho, I bought a fully built FC race car. It's not my first rodeo with the FC and 13B. However, there's a number of aftermarket/race bits on this one, so I am highly unfamiliar with some of it. Seems like pretty standard fare in the road racing world, so I thought I'd give it a shot here.

The car has 2, I think they're called scavenger pumps, low pressure pumps pulling from a fuel cell. They're filling a swirl pot (3" diameter x ~10" tall). So, 2 feeds to the top, 1 overflow off the top, and a line on the bottom going to the fuel filter. The filter goes to the fuel pump, the pump to the front. Splitter to the 2 fuel rails. From the rails, they go into a pressure regulator and then the regulator has a line feeding all the way back to the tank. Everything is using braided stainless steel lines and AN fittings...

So I fire up the scavenging pumps on their own separate switch and give them time to fill the swirl pot. Once I can see gas being returned to the tank, I turn on the high pressure fuel pump. I can hear it running... i know I've got fuel out front (i disconnected one of the lines and fuel came pouring out, but didn't blast out like i'm used to it doing on a stock FC when removing the fuel rails/lines). The pressure regulator reads 0, never budges, even with a vacuum applied to it.

The car will start, hesitantly, on starting fluid. It has been sitting for 2 years, so I'm trying to get it fired up so i can either get the seals to seat better (did MMO, etc.. it was 60+/60+/60+ [piston tester] dry when i did comp testing before purchase.. very even on both rotors) or pull it for a rebuild. So I know it has spark, I know it CAN run... but it seems to be getting no fuel.

The regulator is an Aeromotive A1000, I'm like 90% sure that's the right model (3rd picture, top right). The install directions say there's an adjustment screw somewhere, but it's not labeled in the instructions. Where would that be on this regulator and is it righty-higher, lefty-lower?

It's about 1.5 hours from me, so I can only do pictures/troubleshooting once a week on the weekends. So that has been a PITA. On top of that, there's no cell service at the property, so I can't google a damn thing while i'm there.

Any help, advice, etc would be greatly appreciated. I'd like to get it running/ready to go by August so I can attend a regional drivers education course (SCCA) and get my novice permit.

 

Welcome back! so i think you might try some stuff, mostly to just cover the bases.

firstly, if its easy, i'd do a volume check on the two lift pumps. Mazda wants something like 1.5 Liters in 30 seconds for a 12A peripheral port.
once you know that/those pumps both work then you could test the main pump.
Mazda wants a dead head test,

and then for the pressure regulator the allen with the jam nut should be the adjustment, and lefty should be higher pressure (i think it just compresses a spring)
the stock pressure is like 38psi, but yours might be different cause tuning

 

When doing the fuel pump volume test, I would use a gas can or other fuel-safe container near the engine bay so you can test flow from the lines that go into the fuel pressure regulator. Add a funnel and large fuel-safe hose, or build something temporary using matching male AN fittings if you're feeling fancy.

Stainless braided fuel lines with red and blue hardware could be 25 years old, that color scheme has been around a long time. And remember stainless on the outside could still have cheap rubber on the inside, there's no guarantee those lines will survive well using modern pump gas with ~10% ethanol content. It's probably a wise plan to inspect the inside of the fuel lines and fuel rails, swap the fuel filter element, and have the fuel injectors cleaned and flow-tested. Carlos Iglesias shared some scary-looking photos of fuel lines that sat for a long time: https://www.rx7club.com/build-thread.../#post12428463

 

Appreciate the great suggestions.

I bought a separate fuel pressure gauge w/ 6AN adapter for my next trip out to check pressures at various points in the fuel system.

I guess I'll rethink my 2L soda bottle for volume tests on the low pressure pumps... lmao. I didn't really think 60 seconds or so in a plastic bottle was going to be an issue. It just made it easy to measure/verify whether I was getting ~1.5L in 30s.

I was advised to verify some of the lines for rubber hosing. I was given a LOT of the newer teflon SS lines. I planned to eventually swap them out... I just don't have the cutting tool and right now I'm just trying to figure out if I need a rebuild or not. I really wanted to get through my novice permit without one.

Thanks to both of you!

 

my test container is one for juice, its marked every 100cc too, which is weird but it works!
i'd think a 2l bottle would be ok, literally you're putting fuel in it for 30 seconds, and then dumping it back in the tank.

safety is a concern, obviously. whatever you use it needs to be somewhere it won't fall over when you fill it.

 

So you guys were super helpful.

I took my 2 liter bottle out to the car and started with the low pressure pumps. I'm getting 1.5L in 20 seconds, which is great. So they're working well.

I hooked up a pressure gauge right after the high pressure pump and was getting 40psi or so. I moved it to the front of the car, just before the fuel rail. Again, ~40psi. So I figured wth, and I went ahead and just pulled the pressure gauge off the regulator and replaced it with the one I was using for testing. Voila! ~40psi at the regulator..

So that was super helpful, and now I was down to either the injectors weren't working.... or maybe, just maybe my plugs were F'd... The car came with like 20 sets of spark plugs. Figured it would be easier to change those than fudge with the fuel rail.

She fired up, and much to my neighbor's dismay... i was able to drive it up and down my driveway. Even got on it pretty good, before I thought about the fact the brakes hadn't been used in almost 2 years

Anywho, I gotta go through all the maintenance stuff (change oil, turn the rotors, etc)... then run it around some more and get better compression numbers from it. But I think I'll be getting on with my race season =).

I've attached a video... I'm not sure if I should be concerned with the oil pressure or not... definitely pushing close to 100psi according to that gauge when revving.