launchpad475

500EFI with Vortech
I wonder if you fuel injection experts could help me spitball this gremlin I have with my EFI500/Vortech.

I believe to have either an air leak or partial fuel blockage downstream of the FP regulator. Some of the symtoms… Last week went 82, this week goes 72. We found one side to be lean, and we attributed that to a clogged injector or 2, cleaned the injectors and blew out the rail. Fixed lean problem, still missing 10 MPH. A/F is safe and normal across the board, no missing, seems to run great minus some power and 300 or so rpm.

I also have intermittent starting problem that acts like vapor lock, although it happens cold also. (I know vapor lock can be an issue with the 500, but this motor has never had that issue for 5 years until just recently. ) You can crank and crank and crank, and no fire. Has spark, has fuel at the rail and Schrader valve, spark plugs are dry. It seems random, but once it fires and the system fuel system is primed, everything is normal (except the 10 mph). Relays are clicking, injectors are firing, fuel pumps are pumping.

Some weirdness? The FP gauge on the FP regulator does not change FP when adjusting the FP (like there is air in there). The one time we cranked and cranked and cranked, came back the next day and replaced the fuel water sep and it fired right up. Later that day, same vapor lock symptoms happened. Thinking now there is something goofy going on with the regulator or blockage. I think just cracking that fuel water sep is what made the difference but why?

So my questions. Do the Aeromotive FP reg’s ever go bad, or cause these types of things? When the injectors clogged, could some debris have gone downstream and clogged the lines in the fuel water sep? Any other thoughts?

We are going to try and bypass some things today, like the water separator. I have a new FP reg in the mail, just looking for some more ideas.
Thanks-

TooTall

what's the fuel pressure after the regulators?
Are you running a return back to the fuel tank, or back to the water seperator?

Raylar

KISS -Keep it Simple,
Put a fuel pressure guage on the engine and run it up to your reduced rpm @ top rpm and speed point under load!
What happens to the fuel pressure with this test?
Simple

Best Regards,
Ray @ Raylar

launchpad475

pressure is static about 65. I know it's a lot, but that's the way they installed this system just cranked up the stock pressure.

Doesn't return to the tank, returns to the water sep.

Thanks

launchpad475

That's the weird part about this set up, FP doesn't really change with boost. Well, according to the gauge anyway. A/F is good out of boost and about 11.2 with 6 psi, FP never really changes.

What I'm trying to avoid is making tune changes, as this set up has been solid for a long time (even though there may be better ways to tune, return fuel, etc.)

I'm trying to get back to the baseline of 80 + and 5000+ rpm, and not have funky starting issues.

27 avanti

not sure wat type fuel psi regulator you have,but if its a boost reference fuel psi regulator that has 4 or 5 lines off of it,i would make sure you have all the lines routed rite.i had problem starting and the fuel psi would not go up with boost.found out i had couple of hoses off the regulator routed wrong.

launchpad475

I just have one vacuum line on the reg, goes to intake. I've checked every fitting and connection that I could get my hands on, checked compression, had the injectors flowed, going to try it today. (injectors came back normal)

I plumbed a fitting to return fuel to the tank if the above doesn't work, and have a guest fuel pump to try after that.

launchpad475

None of that worked. Still confused why changing FP on the regulator doesn't really change FP and subsequently doesn't change A/F.
We went 2 full turns on the regulator with no real change, other friends have said 1/4 turn makes big A/F changes on their blower motors.

Swapping out Regulator today, trying different MAP sensor.