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Suspected fueling problem - stumped

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Old Nov 30, 2011 | 04:24 AM
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Unhappy Suspected fueling problem - stumped

Right, so if you have seen one of my threads before you probably have seen me trouble shoot 34 billion things to try get my silly FC started.

Now that I have finished uni for the year, its time to get back into it.

So, I seem to be having problems with what I have narrowed down to be the fuel pump.

I can get it firing with starter fluid but it won't catch. I checked the fuel lines as I have removed emissions and they have been rerouted as per instructions.

I'll double check tomorrow but the 3B pin on the ecu gets 12v at start (which IIRC tells the car to add fuel).

To test the fuel pump I have jumped the yellow connector which should start it when the key is on. With this I have had mixed results, sometimes not being able to hear it - again I will have to have a better look at it tomorrow. I pulled the return off the fuel line and with about 6 seconds of cranking there was only about a table spoon of gas in there. Before I fixed various other issues (the 3b pin not getting power and switching the starter out) this would have had a constant flow of petrol (didn't fire due to a friend switching the leads order >_<)

Is it possible that the fuel pump has just ****ed itself? Or am I missing something.

Hopefully my ramblings make sense.
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Old Nov 30, 2011 | 04:55 AM
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Originally Posted by BurritoBut
Right, so if you have seen one of my threads before you probably have seen me trouble shoot 34 billion things to try get my silly FC started.

Now that I have finished uni for the year, its time to get back into it.

So, I seem to be having problems with what I have narrowed down to be the fuel pump.

I can get it firing with starter fluid but it won't catch. I checked the fuel lines as I have removed emissions and they have been rerouted as per instructions.

I'll double check tomorrow but the 3B pin on the ecu gets 12v at start (which IIRC tells the car to add fuel).

To test the fuel pump I have jumped the yellow connector which should start it when the key is on. With this I have had mixed results, sometimes not being able to hear it - again I will have to have a better look at it tomorrow. I pulled the return off the fuel line and with about 6 seconds of cranking there was only about a table spoon of gas in there. Before I fixed various other issues (the 3b pin not getting power and switching the starter out) this would have had a constant flow of petrol (didn't fire due to a friend switching the leads order >_<)

Is it possible that the fuel pump has just ****ed itself? Or am I missing something.

Hopefully my ramblings make sense.
My fuel pump always comes on when i turn the key on in my 88 gxl. Try hitting it with a rubber hammer. Not to hard. should spin up. somtimes they are sticky. Also check the EGI head fuse or EJI i forgot what its called
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Old Nov 30, 2011 | 04:58 AM
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Cheers,
Yea the fuses are all good (never hurts to double check). The car has been sitting for a year and a bit now, but it was running perfect not so long ago >_<.
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Old Nov 30, 2011 | 05:11 AM
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I noticed in your profile that you have a series 4 car. Is it N/A or turbo?

Are you sure that you didn't accidentally switch/mix up the fuel lines? Do you have access to an extra fuel pump to test in your car??
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Old Nov 30, 2011 | 09:24 AM
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If everything was good the fuel should pour out of the return line so maybe there is something blocking the fuel within the fuel rails perhaps so remove the feed (send) line to the engine and check fuel at that point.
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Old Nov 30, 2011 | 06:24 PM
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Well, usually if your pump isn't turning on all the time, that'd be the first place to check. Have you done the re-wire for the pump?
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Old Nov 30, 2011 | 06:43 PM
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Cool, thanks for the info.

Its a 1987 S4 turbo. I have the fuel lines as per the emissions removal guide, fuel filter to primary rail then secondary to return.

Unfortunately I don't have a spare on me. I'll check flow from the filter and that will tell me if its between there and the pump or in the rails.

I havent rewired the pump yet.
Is it possible the tank sucked some dirt up or something and blocked the line?
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Old Nov 30, 2011 | 06:54 PM
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The pump has a fuel sock on it to prevent debris other than fuel to get pulled into the fuel system so yes, it is possible it could be clogged.
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Old Nov 30, 2011 | 07:01 PM
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just pull the pump out and inspect it, takes about 5 minutes. you can also visually see what kind of crap has accumulated in the tank over the years while it's out.
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Old Nov 30, 2011 | 08:07 PM
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Interesting, its flowing like a **** through the filter. When I pulled the line off there was a lot of pressure. There must be a block somewhere in the rail. Its possible that I stupidly left a piece of plastic shopping bag in there from when I was masking and painting. Ill now pull the top off and start inspecting.

Is there any injector seal that may have caused this? IIRC there isn't one in the actual rail except for the o-ring on the top of the injector (which I replaced) and would be unlikely to pop off.
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Old Nov 30, 2011 | 08:48 PM
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Ahh haa!

Found the issue...

This thing (pulsation damper?) on the end is completely blocking the flow.


What should I do?

Researching niow...
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Old Nov 30, 2011 | 09:33 PM
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Pulsation damper removal mod. Is in the archives, I'm sure.
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Old Nov 30, 2011 | 09:42 PM
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uhh, that's not a pulsation dampener. someone put a second fuel pressure regulator on your inlet pipe... it's trying to push fuel through that pressure regulator backwards, which will allow a tiny bit of fuel to flow, about a tablespoon every few seconds as you said earlier.
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Old Nov 30, 2011 | 09:45 PM
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Originally Posted by Karack
uhh, that's not a pulsation dampener. someone put a second fuel pressure regulator on your inlet pipe... it's trying to push fuel through that pressure regulator backwards, which will allow a tiny bit of fuel to flow, about a tablespoon every few seconds as you said earlier.
Plus he says he has an S4 but the FPR looks more S5'ish.
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Old Nov 30, 2011 | 09:57 PM
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Originally Posted by BurritoBut
Ahh haa!

Found the issue...

This thing (pulsation damper?) on the end is completely blocking the flow.


What should I do?

Researching niow...


did the car ever run? thats strange. never saw that before, is that an s4 fuel rail? My s4 rail does not look like that
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Old Nov 30, 2011 | 10:09 PM
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it's a series 4 non turbo primary rail with a series 4 turbo fuel pressure regulator, located on the inlet where the pulsation dampener should be.

all series 5 FPRs were moulded to the stamped steel rails.
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Old Nov 30, 2011 | 10:34 PM
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Well **** no wonder its not starting...

I had a few fuel rails when I stripped it down and must have swapped it with another one because it was running fine before I took it off the road. I didn't even notice >_<.

So should I just remove it and do the banjo bolt mod or will I need to get a turbo rail?
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Old Nov 30, 2011 | 10:35 PM
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Doesn't your secondary rail have a fuel pressure regulator on it?

The banjo bolt modification is for the pulsation dampener... Not for the FPR.
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Old Nov 30, 2011 | 10:47 PM
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pull out your proper turbo primary rail and swap it if it is a turbo car.

in either case it's up to the condition of the part, i wouldn't junk the dampener if it's relatively new. if it's old and the screw is loose, order the banjo bolt.

Originally Posted by dwb87
Doesn't your secondary rail have a fuel pressure regulator on it?

The banjo bolt modification is for the pulsation dampener... Not for the FPR.
i'm assuming it now has 2 FPRs, one on each rail otherwise there would be no return outlet on the secondary rail if the FPR was switched in position with the PD.

Last edited by RotaryEvolution; Nov 30, 2011 at 10:50 PM.
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Old Nov 30, 2011 | 10:53 PM
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Originally Posted by Karack
pull out your proper turbo primary rail and swap it if it is a turbo car.

in either case it's up to the condition of the part, i wouldn't junk the dampener if it's relatively new. if it's old and the screw is loose, order the banjo bolt.

I sold off the original one I think . Whats the difference?


Looks like the FPR and the PD have been switched over, here is the secondary rail...

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Old Nov 30, 2011 | 10:55 PM
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I need to learn to look at pictures instead of just reading the text hahaha
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Old Nov 30, 2011 | 10:58 PM
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the turbo rail has a more stout casting and larger diameter bore. you can run the n/a rail but the turbo rail is more ideal.

yep, just swap the FPR and the PD positions, should cure your issues.

on second thought that could well be a turbo rail, sorry i'm not at my shop there was 2 versions of the n/a rail and 1 of the TII. the n/a rail had a ski slope on it and the turbo had a rib on it, as far as i can remember now after thinking more about it.

Last edited by RotaryEvolution; Nov 30, 2011 at 11:02 PM.
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Old Nov 30, 2011 | 11:18 PM
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Originally Posted by Karack
the turbo rail has a more stout casting and larger diameter bore. you can run the n/a rail but the turbo rail is more ideal.

yep, just swap the FPR and the PD positions, should cure your issues.

on second thought that could well be a turbo rail, sorry i'm not at my shop there was 2 versions of the n/a rail and 1 of the TII. the n/a rail had a ski slope on it and the turbo had a rib on it, as far as i can remember now after thinking more about it.

Oh ok, my spare parts motor was a turbo so hopefully these rails are from it.

The PD goes on fine but the FPR doesnt look right. Should the return nipple be in the grove?




Here is the primary - Now with new PD!



ALSO AN IMPORTANT QUESTION - Should I be able to blow air through the FPR? At the moment I can't at all
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Old Nov 30, 2011 | 11:28 PM
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i can't really think of why that second locator block is there as i don't have any references in front of me. it should work the way you have it though.
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Old Nov 30, 2011 | 11:33 PM
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Sweet as, and should I be able to blow air through it or I guess it would require the pressure of the fuel pump to open it.
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