BrianKeithSmith

Little update - I pulled the fuel filter out tonight, and cut it open. The material was brown, and discolored, but in reality it didn't look that bad (I've never cut one open before, so have no basis to compare to).

I was expecting to find some larger chunks in there. Wasn't the case.
Will replace the filter tomorrow, if I get the time.

Brian

sand_man

see...SEE, if you were still on CIS you'd just adjust your WUR pressures and your AFR screw (10,000,000,000,000 times going from rich to lean and then back again only this time a c_nt hair less) and bada-bing, you'd be right back on the track! None of this tom foolery EFI monkey business! Compoooters and cars...sheesh, who would have thought! Oh how I love CIS!


---make sure you're your sarcasm cloking device is working properly before reading the above comments!

A930Rocket

Don't ask him how the new fuel filter change went...

BrianKeithSmith

Yeah, I had to pull the top fitting off the filter and replace it so I can attach my lines. I put it on, attached it to the lines, had a slight leak, so I tightened the fitting a little more and stripped it out.

Brand new $25 filter, gone....

Oh well...

On a good note, I did vacuum test my the regulator/damper(s) on the 3.2 intake, and they are both holding vacuum. So they must be OK.

Brian

BrianKeithSmith

BTW, do other EFI conversion users use the stock 930 filter, or do you buy a different filter that doesn't require a fitting change?

DonE

Everything I am using is stock.

BrianKeithSmith

How'd you get the 3.2 intake's Fuel line to hook up to a 930 filter then?

Brian

BrianKeithSmith

OK gang. Today I did some analysis - didn't get very far though.

1. Replaced fuel filter

2. Check fuel pump output - I checked it by hooking up to the line that feeds the fuel filter, allowed it to run for 30 seconds, and got just a tick over 1 liter of fuel in my beaker. Looks like I should have gotten close to 1.2L, I'd say mine was closer to 1L.

3. I pulled vacuum on the pressure regulators and their lines that lead to the intake, I pulled -70Kpa of vacuum, and after about 5 minutes it had dropped a little less than 5 Kpa. So I'm going to assume that vacuum/lines/regulators are OK based on that.

4. Made a couple of passes down a street near my house, got some datalogs, AFR still going high above 5000 RPM.


So where should I look next?
1. Should I have the injectors checked out? If so - to whom?
2. Should I send the computer off?
3. Any other ideas?

Brian

BrianKeithSmith

Does anyone have a favorite fuel pressure gauge they use. If so where'd you get it?
And where did you mount it, in regards to the sequence in the line, between fuel filter and fuel rails, on the return???

With the 3.2 regulator/dampers, what pressure should I see at idle, and at full boost.

Thanks,

Brian

fast951

Looking at your rebuild pictures, it apperas that you are using the Carrera fuel rail. If this is correct, you can purchase a fuel rail end-cap, drill & tap and install a mini fuel gauge (summitracing has them SUM-800199). Remove once testing is complete!
The problem is the ability to view the gauge. The intercooler pipe might be in the way, and unless you are running on the dyno there is no way to see it.
If you want to test the pressure while driving, you have to come up with some sort of hose to bring the gauge somewhere where you can see it. Not recommended, fuel is not something to experiment with.
Your best bet is to get a electronic fuel gauge and sender, a bit more $, but much easier to use in this application. Again, summitracing offers various brands...

Did you determine if the AFR is boost related. I wonder if you lower boost a bit, does the car leans out at higher RPM. (increase boost, does it go lean sooner)?

BrianKeithSmith

Not haven't determined if it is boost related.
Like you mentioned, I don't want to run a hose into the cockpit... Bad idea there. I'd like to find a setup that places a gauge in the engine bay, with an electric gauge in the cockpit.

As I understand it, with the rising rate regulators, like are stock with the 3.2 intake, as boost climbes, fuel pressure at the rails should climb? correct? So if I'm at say 42-45 psi at idle, I should see what, 55-60psi under boost?


Brian

Geoffrey

You should see 55psi at idle without the vaccum line connected, that is called the static pressure. Once you connect the vaccum line it should drop by about 5psi and under boost you should see about 70psi at 1 bar of boost.

Definately remove the gauge after you are done testing, I have seen them leak.

BrianKeithSmith

I assume that the gauge/sender should be mounted on the return line at the exit of the fuel rails?

If so, does anyone know what size fittings are on the 3.2 intake return line?

Brian

fast951

You install the fuel pressure gauge (or sending unit) on the rail. The return line (after the regulator) is low pressure. You want to determine the fuel pressure as the fuel gets delivered to the injectors.

BrianKeithSmith

Well, tonight I think I may have found the problem. 0 volts going to the rear pump.

When I turn on the power on my car, the fuel pumps run for 20 seconds. It sounded like the rear pump was working, I just figured it was maybe dying. Turns out, it wasn't running, what I must've heard was the sound of it spinning as the front pump pushed fluid through it.

Ran a new wire to it tonight, we'll see what happens tomorrow.
Tonight it put out between 1.3-1.4L in 30 seconds after the rear pump got voltage. So I'm guessing, based on that, that the problem is resolved, but tomorrow I'll take it out for a spin and log som AFR's...



Brian