idle problems and fuel pump resistor relay, related?
 

Well, I fixed that water thermo sensor, and the starting problems I had went away, however I still cannot get an idle.

I went ahead and checked the error codes, and I was given a fuel pump resistor relay error (five long and one short). I'm confused to how this error could come in the first place, the engine runs, so its getting fuel, which means the fuel pump is getting power, which means the relay is working..... right?

I do have some modified wiring in that area however. I run an inline pump because my car is an FB, and I do have the two positive wires comming from the relay mergerd into one wire and then connected to the positive terminal of the fuel pump. I dont think theres any problem there.

What do you guys think?

the "fuel pump resitor relay" on an FC is on a metal bracket behind the pass head light. I'm doubting you even put it into your FB. what it does is lower the fuel pump voltage from 12v down to 9 volt at idle and cruising. to lessen the wear on the pump. and to make sure you are not over powering the FPR when you don't need much gas. it's really not needed. but the car might run a bit richer at idle if it's always at 12v. unless you have a S-afc or something to lower fueling

nope I swapped it over, its right by my air filter. The relay works, giving power to the fuel pump during crank, and only whern the AFM is keeping it on. its there and it does everything its supposed to do.

I just cant figure out why it would give me an error code. I mean if I cant idle, and I'm getting a fuel pump resistor relay error, I can pretty much assume it has something to do with it.

However the one thing that it really might be is that there are 2 wires that are on the bottom right and left of the fuel pump resistor relay plug. Those both go to the positive terminal of the fuel pump right? How do you turbo guys wire up a pump when you change to and inline pump?

with the car running. check the voltage of the fuel pump power wire. and do the same under load (probably need a friend for this with longer voltmeter wires)

then you can tell if infact it is working.

just because the pump is running. doesn't mean the resistor is.

Know what? My car tripped a fuel pump resistor code after i left the ignition on for about 20 minutes while working under the hood.
Dunno why
I reset the ecu, and it's never given me a problem since.

how exactly do you test it under load. I allways thought "underload" ment while the car is driving. It would seem that would be quite a task.

On a second note, when getting the code I noticed this. When I start the car normally, the checking engine light comes on with all the other idiot lights, an dthen turns off. This would make me think that I dont have a problem. Isn't that normal?

However its when connect the test connector that I get the code. (like normal) My question is, if I'm getting a code, shouldn't the check engine light STAY on? I allready tried to disconnect the battery to clear the code and it still comes back.

ah, you posted while I was replying fingers. Mabey I'm not reseting the ECU right? I'm just dissconnecting the battery.

under load would be like over 4000rpm and over 50% throttle or so. probably under boost as well. as oposed to "crusing"

like I said you'd probably need a 2nd person there to read it.

the engine light will turn off when you put the keys to on after a couple secs. if you ground the test connecter. then it'll start flashing codes.

yeah, but if you have a deffinate problem, doesnt the check engine light stay illuminated?

Not neccesairly. Sometimes it does, sometimes it does not. It depends on the severity of the issue.

Codes like AFM will definitely trigger the CEL.... but things like knock sensor or TPS will not.

ok that clears that up. OK so two more questions.

What is the correct way to reset the ECU. I want to make sure I'm doing it right.

And the fuel pump voltages, they should be 9v under 4000 rpm and 12v above, when in neutral at least, right?

just unplug the power to the battery for a few mins...
the fuel pump voltage is only decreased at idle and cruise. if it's 9v at 4000rpm under boost, i'd be scared, very scared.

well I chose to ignor the code for the time being, and I went to look for other posibilities why the car wouldn't idle.

I have a block off plate for the ACV, so I figured I'd remove the acv and put the plate on just to make sure my acv wasnt causing an internal vacuum leak.

Well I played with teh timing and the air adjust screw, and you know what? I got it to idle! It held at about 1,000 RPM, lumpy as HELL. But keep in mind, the timing was really really really advanced, and the air adjust screw was allmost all the way open. I tried moving the timing back to normal, and there wasnt a way in hell it would idle. So its a DAMN vacuum leak. And its still a leak even with the acv removed?!?!

The one thing I'm not sure of is this. Even though I have my acv on, I do not have my air injection for my catalytic converter hooked up. I have to get a new hose that will work with the second gen manifold.

So, my air injection line on the manifold is wide open, and when I still have the acv attached. Could this be causing a vacuum leak and my acv is really just fine?

bump