fuel pressure gauge and tuning issues

[TexasRed]

Ok, got the 383 built and in truck.

Specs:

350 with 400 crank, .030 over.
vortec heads
264 isky mega cam
headers
Accel distributor with jeg's coil, borg warner module
MSD wires
Autolite platinum plugs
summit racing carb 600cfm
electric fuel pump/regulator


OK, so I've got the adjustable vac can at 4 turns in, to give me like 12 or 14" of vacuum advance total.

Couple questions/concerns:

1) I've got a fuel pressure gauge setup right past the regulator inline to the carb. I'm guessing that's wrong? It doesn't read any pressure.

I've got a mr. gasket style gauge and used http://www.summitracing.com/parts/SUM-G1710/ to hook it up inline. Is that wrong? It shows nothing at idle, and nothing when the engine is off but pump is on.

2) Right now I've got the advance on manifold vacuum. I could switch back to port. I've got the carb's mixture screws like 1.5 turns out. I thought I had everything fairly well figured out but I had the truck fully warm, went to a store, came out not 10 minutes later, it started fine (surprised me due to the starter not heat soaking from the headers) and but when I put it in gear, it wanted to die on me and I had to keep my foot a little in it to keep her from dying at first. After being driven down the road, she seemed to be better. I think the initial is around 12 degrees, but I need to check. Any help would be appreciated. This maybe connected to the issue above.

[VileZambonie]

What is the gauge range 0-10psi? Did you screw it in too far?

Kepp the vacuum advance connected to manifold vacuum.

What's the fuel pump you are using?

[TexasRed]

Is it possible to screw it in too far? It's a 0-15 psi gauge. The cam was broken in and I never saw the fuel in the sight glass drop, so I don't know if the gauge would be restricting flow that much. Granted, it's not like the engine was heavily loaded so I'm sure some could slip past.

This be the pump and regulator: http://www.skipwhiteperformance.com/detail.aspx?Item=2803-2852

I've got to figure out how to get the hei adapter connector from summit to work so my tach can tell me the RPM. I don't have the ear for it. What RPM should I set it at? I've got a 700r4.

[VileZambonie]

Yes you can screw it in too far. You've adjusted the regulator and no change? Bypass the regulator and see what it reads. Maybe you have a bad regulator.

I'm not sure what you are saying about your tach and HEI 

[jaredts]

You say you've got an Accel distributor, but it doesn't have a tach output and requires an adapter?  I would have thought it would be setup like a stock HEI with the tach output.

[TexasRed]

HEI: Previously I was using a flat blade connector (this is a tach for tuning only) and I bought the connector from summit but that doesn't seem to wanna work. No biggie, I'll figure something out.

PSI: I screwed the adjustment screw almost all the way in on the regulator and it started to show some PSI. Like almost 3 all the way in. Bypassing the regulator it shows me to have around 7 psi from the pump. Should be higher, no? So maybe the pump is bad?

Well, this probably doesn't mean anything now that I think about it but I was using one of the ports as a return line with a restricted to a 1/4 outlet. I don't think that would affect the fuel pressure on the line to the carb, would it?

Oh, I unscrewed the gauge some, it went up half a psi, but it also dripped fuel.

[Captkaos]

That pump is only good for 14lbs, the regulator is good for 3-12, so halfway would be 7.5lb, if you bypass it and it only shows 7, the pump isn't putting out peak pressure.  Just remove the regulator and see if it is better.  Sounds like you are starving it of fuel.

[TexasRed]

You mean run pump to carb and see if the truck runs better?

[VileZambonie]

Bypass the regulator. Run an inline filter. If you have 7psi you'll be ok. Fuel volume is critical not pressure with a carb. The only thing you need to be careful of is too much pressure. Too much fuel pressure can cause the fuel bowl to overfill spewing fuel out of the carb and creating a potentail fire. If the pressure looks ok, run it that way until you can get your new regulator.

[TexasRed]

Well, before I do that, Imma use a universal vacuum connector and see if I can hook up my harbor freight vacuum gauge/pressure testor to see if the numbers come up the same. Perhaps my gauge is just bad ( I doubt it).

I may have to change pump and regulator since I'm not getting enough pressure. Might be able to even find a quieter pump.

[TexasRed]

Update:
With the pump connected directly to the carb bypassing the regulator, my harbor freight gauge read 7.5 psi with the carb rated at 7 psi max and I could see the gas in the sight glass way much higher than before, so I'll see if I can get one of those cheapie regulators and a new gauge. Maybe just the regulator.

[TexasRed]

Well, the spectre regulator somehow only puts out something like a couple psi on my harbor freight gauge. Doesn't even appear to register on the mr gasket gauge. Ah well. I think I'll just get an E84070 pump from a local autoparts store. That way I can skip the regulator for awhile and put one on just to keep the pump alive for a long time.

[TexasRed]

It looks like the hot start problem is gasoline percolation. I'm using a one inch spacer that's aluminum to get enough space for the carb linkage.

This one specifically: http://www.summitracing.com/parts/MRG-4945/

I did buy another one of these along with the one I got with the carb: http://www.summitracing.com/parts/SUM-M08005/

Should I run the 2 insulator gaskets and maybe a half inch spacer to keep the same geometry for the 700r4 linkage?

[VileZambonie]

Any particular reason you aren't just running the mechanical fuel pump? You don't need anything fancy for a carb set up like yours

http://www.autozone.com/autozone/parts/_/N-8vcz2;jsessionid=1A28EE37C15143E158C8D93972505FE3.diyprod1-b2c1?filterByKeyWord=electricfuelpump&fromString=search&isSearchByPartNumber=false&itemIdentifier=191411_40066_7539_&skuDescription=AirtexMaster%2FFuelPump&store=2914

This will work fine.

[TexasRed]

vortec block and I don't think that everything's machined for the mechanical fuel pump. Plus if not driven every day, I had to extend crank to get fuel into the bowl.