# Help! 00135 low fuel rail pressure



## jagerauto (Jun 4, 2009)

Ok so car running badly, pulled the fuel pump to find that the follower was so gone it was stuck to the pump. 

We replaced the cam lobe, fuel pump, follower, and housing. All New OEM parts. New pump came with a new sensor on the top but not the bottom. 

After this we still get a code for fuel rail pressure too low. At one point we got a code of too high, and heard a pinging coming from what seems the brass valve on the rail. Sure all signs point to replacing the valve, but we have run Into this before and had no luck. 

Before we go replacing anything is there anything to check?

In measuring blocks vagcom reads actual psi (idle) 7.00 bar, specified is 50.00. Upon revving it stays at 7bar. Unplugging the sensor on the right of the rail makes the readings on vagcom range from 5bar to no higher than 10bar. 

Pictures for consideration.


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## low_passat (Sep 11, 2010)

How did you time the cam lobe? Even VW pays to replace the entire cam under the extended warranty.


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## jagerauto (Jun 4, 2009)

low_passat said:


> How did you time the cam lobe? Even VW pays to replace the entire cam under the extended warranty.


pressed the old one off and pressed the new one back on exactly how the old one was. Not rocket science.. I wouldn't see how the placement of that lobe would affect the timing. the pump just pumps.. the more rotations of the cam the more fuel.. Or is that all there is to it?? 

We've done this plenty of times, only had two fight us, this being number two. We try to offer a cheaper solution than replacing the entire camshaft. The last one was a 07 EOS, and after replacing everything on the rail, the dealer had to call in engineers even after they replaced the entire camshaft. Of course they did not tell us what the hell the problem actually was but instead tried to blame it on us. Which was quickly shot down and not brought back up. 

It should be just like the H2sport kit install. 
http://www.h2salesandservice.com/Fuel-Pump-Upgrade-p/h2s-06f-103-498.htm


If it is something where the cam lobe must be in time with the pumping of fuel and it possibly being off a degree then I guess we will have to go back with another camshaft and replace. I just dont see it mattering that much.. But I'll bite.. any suggestions?


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## jagerauto (Jun 4, 2009)

Even if that were true, we only get a reading of 7.00bar at all times. The pump would still pump more than that period even if it was pumping at the wrong time. 

Last Time I researched it down to being wiring. whereas people have the same low pressure code / high pressure codes, due to faulty wiring. But we didnt want to keep replacing everything on the car and not making progress. That's only acceptable if your a dealer I suppose. That's literally what they do when they get the low pressure codes and the followers are fine.


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## low_passat (Sep 11, 2010)

I personally have no idea if the lobes are timed or not, I was just curious. The way I see it though, if this a viable option, why does VW not do it, and save cost on warranty repairs.


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## GolfRS (Feb 4, 2006)

Never seen a solution like yours,not really that practical IMO.

Thinking it through, timing the lobe could be one issue, but my
opinion is the pressed on lobe might actually be rotating on the
camshaft and hence the pump piston is not lifting.

I don't know how you made or found these lobes but it could
be an issue of wrong machining/replacing the lobe.

I would check for rotation, but i don't think you could diagnose it
by hand.It could need quite a lot of force to rotate it.


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## jagerauto (Jun 4, 2009)

We took the pump out and made sure it's spinning. There isn't much force applied to the lobe. 

We use bran new OEM lobes off new camshafts.


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## jagerauto (Jun 4, 2009)

We took the pump out and made sure it's spinning. There isn't much force applied to the lobe. 

We use bran new OEM lobes off new camshafts.


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## jagerauto (Jun 4, 2009)

Looses it's fuel prime and is hard to start after sitting overnight.


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## jagerauto (Jun 4, 2009)

Checked the lobe to entertain your accusation.. The pink was put there before removing old cam lobe. If it's off it's not by much. And this tells us it's not spinning freely.


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## jagerauto (Jun 4, 2009)

P1250 fuel level too low. Is a code as well. Also saw this on the eos we had issues with. Did some research and it has nothing to do with gas in the tank.


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## jagerauto (Jun 4, 2009)

Getting a pinging sound from the rail when it decides to run high fuel pressure. When it has high fuel pressure it pings and sits around 120bar when requesting 50bar. Sound seemed to be coming from the brass valve so we swapped it for one we had laying around. Same sound unplugged sensor on fuel rail under intake and car shut off. (Beforehand it was idling with high rail pressure an making the pinging) 

Guess we will replace sensor and see what happens.


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## jagerauto (Jun 4, 2009)

Still nothing. Replaced all the sensors, and the brass valve. Took the manifold off and cleaned the fuel rail. Nothing.. Idles great and only revs to about 2500 cleanly and 4k very rough. If you hold the pedal all the way to the floor it sometimes revs all the way up and the computer reads fuel pressure no lower than 120bar. An throws a code for high rail pressure.


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## jagerauto (Jun 4, 2009)




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## low_passat (Sep 11, 2010)

Inspect the N276 thrust sensor on top of the hpfp to make sure it's not cracked. 

Try a different hpfp, or swap the N276 from the old damaged pump just to see if it still does it.


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## xtravbx (May 21, 2005)

In 4 results


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## jagerauto (Jun 4, 2009)

low_passat said:


> Inspect the N276 thrust sensor on top of the hpfp to make sure it's not cracked.
> 
> Try a different hpfp, or swap the N276 from the old damaged pump just to see if it still does it.


Tried both these options. 

Upon revving motor the N276 starts making a "squeak/ping/belt slip sound). At that point (and this doesn't happen all the time) the fuel pressure jumps to 120bar and will not stop making the sound or drop pressure until the N276 is unplugged. And then it goes back to 7bar.


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## jagerauto (Jun 4, 2009)

:screwy:


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## [email protected] (Jan 2, 2009)

The cam lobe is timed, and it is critical. The electronic opening and closing of the fuel inlet solenoid is phased with the cam profile. I would verify that the various check valves etc are working and that the ECU is firing the solenoid. If all of that is working, replace that entire intake cam. 

If you want to verify that it's the phasing and you have the spare old pump, you can do this... Pull out the electric solenoid from the spare pump. There is a pin that sticks out of the face of it when it is de-energized. This holds the inlet valve OPEN. You can carefully file down that pin without damaging the face surrounding it. If you suddenly have 130+ bar rail pressure, it's your cam phasing. DO NOT run the car continually like this as you are running the HPFP wide open on the rail pressure relief valve and it WILL wear out and fail. 

Do that at your own risk of course.


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## GolfRS (Feb 4, 2006)

I'm with pete as i already mentioned.

I believe the whole issue is with your (no cam replacement) technique.

I think you should have the whole cam changed.


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## jagerauto (Jun 4, 2009)

swapped in a new ecu, and got normal pressure, until the immo kicked in and cut the car off, so were getting the ecu programmed and seeing what happens.


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## jagerauto (Jun 4, 2009)

GolfRS said:


> I'm with pete as i already mentioned.
> 
> I believe the whole issue is with your (no cam replacement) technique.
> 
> I think you should have the whole cam changed.


checked the lobe, somehow it got put on 180deg out. took it off, pressed it back on so the pink marks line up with the cam and it fired right up! 

Lesson learned, if I thought that the cam lobe was put on wrong in the first place that would have been the starting point, but miscommunication of how the old one came off and how the new one was supposed to go on, messed us up. 

I defiantly think changing the cam is the way to go, we wont offer the lobe only replacement anymore. Unless they are in dire need of a good deal.. 

For those that aren't experienced enough to remove the cam, this is a good way to get around that. Turns the whole job into an hours work, vs 2-3 and waiting for rtv to dry. But yes placement of the lobe is essential. We have always made sure to put it on exactly as it came off, but its not hard to get it backwards if you will. Make sure you mark it and pay attention to what your doing. My suggestion only mark the lower slit on the lobe, and transfer it to the new lobe, that way it only goes on one way. 

Now we need to figure out a solution to the cost of all the parts necessary for this job. Prices are outrageous :laugh:

Thanks for all the help!


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## GolfRS (Feb 4, 2006)

jagerauto said:


> checked the lobe, somehow it got put on 180deg out. took it off, pressed it back on so the pink marks line up with the cam and it fired right up!
> 
> Lesson learned, if I thought that the cam lobe was put on wrong in the first place that would have been the starting point, but miscommunication of how the old one came off and how the new one was supposed to go on, messed us up.
> 
> ...


:thumbup:


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## joshg21 (Oct 28, 2015)

What did you use to press the new cam lobe on?


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## joshg21 (Oct 28, 2015)

What did you use to press the new lobe on?


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## jagerauto (Jun 4, 2009)

Tapped it on with a dead blow or a rubber mallet. It MUST go on the exact way the old one came off.


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## joshg21 (Oct 28, 2015)

Thanks


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