VW T4 Forum - VW T5 Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Hi,
I am new on this site and trying to get some information on my 2015 Crafter.
I have a fault code coming up p0087 low fuel rail pressure, I have changed the fuel filter, the fuel pressure relief valve, the fuel pressure sensor, and the high pressure fuel pump, the van is still going into limp mode and coming up with the same fault code.

Has any one got an idea on what the reason might be.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #3
Hi Hifly,

Yes it does have a in tank pump, but as far as I know that pump only works for a few seconds when you turn on the ignition. Whether or not that's right I don't know as I can't get a workshop manual to look into things like that.
If the tank pump should be running all the time then that would be the problem as it's not running constantly.

Thank you for your reply.
 

·
Premium Member
Joined
·
233 Posts
when does it go into limp mode? at full throttle at around 300rpm?
Mine (not a crafter, T5.1 2.0 CR 140 CAAC)has been doing this for a while now and i'm led to believe by a diesel specialist that it's probably one of the injectors leaking back under load and dropping the pressure, but it's a big job to find out which one it is as they all have to come out and be bench tested. and then new injectors cost a body fortune!
 

·
Registered
Joined
·
4 Posts
Discussion Starter #5
Hi fenwick458,
thanks for your reply, I am thinking about the in tank pump, I took the pump out of the tank and run it up on a 12volt battery, it worked fine so I re installed it back in the tank, I then run power to the pump and purged the system.

There is a problem with the wiring as the pump wont run when i turn on the ignition.
What I need to know is should the in tank pump run constantly when the engine is running (mine isn't not running at all )
 

·
Registered
Joined
·
26 Posts
What size engine do you have and do you have the engine code ie BJK,CEBB?
Have you checked the relay and fuse for the pump?

@Fenwick458 There is a pressure retention valve on the fuel return line that could have failed. A quick, free way of testing for bad leak off on an injector is to pinch/clamp the fuel return line after each injector, one at a time, to see if the low pressure problem dissapears.
 

·
Premium Member
Joined
·
233 Posts
@Fenwick458 There is a pressure retention valve on the fuel return line that could have failed. A quick, free way of testing for bad leak off on an injector is to pinch/clamp the fuel return line after each injector, one at a time, to see if the low pressure problem dissapears.
is this going to work when my fault only appears at 3000rpm?
i was told that they can be tested using diagnostics at idle, but thats a waste of time because 99% of the time the faults only appear at higher revs and the only way to fully test the injectors is to have them removed and tested.
 

·
Registered
Joined
·
26 Posts
If it is a leak off problem with an injector this test should prove it (at any rpm). Does it go into limp mode at 3000rpm everytime even when stationary? If it does, then you can do this test stationary rather than clamp no.1 and road test upto 3000rpm, swap to no.2 and road test upto 3000rpm etc.
Normally you have hot start problems with a worn injector (too much leak off). Are you getting the same code as o.p and have you had the fuel pressure regulator changed?
 

·
Registered
Joined
·
4 Posts
Discussion Starter #9
Hi all,
Back again, I was told that later crafters suffer from fuel injector back feed quite a common problem.
I done a back feed test and found no1 and no3 injectors were back feeding by as much as twice as much as no2 and no4 injectors, that would make sense on my low fuel rail pressure.
 

·
Premium Member
Joined
·
233 Posts
I've still gotten nowhere with this fault, had all 4 injectors removed and took them to an injector specialist who said they were all fine:*
 

·
Registered
Joined
·
26 Posts
I've still gotten nowhere with this fault, had all 4 injectors removed and took them to an injector specialist who said they were all fine:*
Did they give a readout of all the tests they performed and the results of each test?

Have you tried, tested or changed any other parts?

 

·
Premium Member
Joined
·
233 Posts
Did they give a readout of all the tests they performed and the results of each test?

Have you tried, tested or changed any other parts?

Didn't get a readout,, I did ask he said this:
My test bench is old and therefore does not have a computer print out
the readings taken are just visual from the graduated test tubes and therefore will not mean any thing to any one else
each test bench manufacturer has their own test plans to work to, so my readings wont mean anything to any one only me. there is no direct comparison between test benches only of the same make and type
The tests carried out were electrical on piezo stack and delivery and back leakage on the test bench
hope this helps


after the injector test last week, I decided to try and rule out the possibility of it being a bad DRV by swapping it with a working DRV from my friends van. I took mine for a test drive and it was exactly the same (limp mode at 3000rpm)
then when swapping them back over I couldn't get the plug off the IMV on the top of the pump (to remove the loom, in order to move the fuel pipes out of the way to swap access the DRV) so I had to remove the IMV, and whilst they were out decided to swap them to see if that made a difference.

as a result, my friends van now goes into limp mode at 3000rpm!
and mine was even worse, goes into limp mode just above 20000rpm, and the rough idle problem has been on and off over the last few days. fault code coming up is still the same 0087 low pressure.

Yesterday I got a new bosch IMV and fitted that, but it didn't make a difference.
I also bought a new pressure sensor, but couldn't swap that as i didn't have the right tools, need a 27mm deep socket. hopefully i'll get that done today if i can borrow one.
I've tried the basic settings in VCDS described here but that didn't make a difference.


One solution to the trouble code here in this thread https://www.vwt4forum.co.uk/showthread.php?t=1789383
is that the plug for the pressure sensor?
 

·
Premium Member
Joined
·
233 Posts
well i think I have found the problem, did a pressure test using VCDS and the pressure drops right off as soon as the engine goes off. as in it drops from 28000 to 60 straight away, thats a pretty big leak isn't it?
 

·
Registered
Joined
·
26 Posts
That's normal for the pressure to drop when the engine is switched off, power to the regulating valve closes the valve to build pressure, with no power it reverts to it's default position of open - no pressure.
I think there must be a couple of issues, you would say the imv was bad because it failed on your friends van but your van still failed with his imv and your new imv. I would record some live running data (rpm and fuel pressure) upto the fail point to see if it's struggling to build pressure or if there is a sudden drop of pressure. A sudden drop could indicate the regulator is opening were as struggling to build pressure would indicate a bad/worn pump or flow restriction of some sort. When was the filter last changed?

The connector plug in the other thread was the fuel pressure sensor plug according to part number.
 

·
Premium Member
Joined
·
233 Posts
filter last changed in 2018, it's done 15,000 miles since then.

I've now put my IMV back onto my van, and my friends IMV back onto his, so essentially we are now back to "how it was" but both vans have the same fault now, well similar,

mine goes into limp mode just over 2000rpm (p0087 low pressure)
and has developed a rough idle, intermittently (P1065 pressure regulation discrepancy)

and my frineds van goes into limp mode at about 2500rpm (p0087 low pressure)

so it looks like it's something I've done when putting them back together, is it possible theres an air lock in the fuel system, or a blockage??

I'm trying to find somewhere to take the van to because I think i'm out of my depth and I just don't have the time, but can't seem to find anybody!!
 

·
Registered
Joined
·
26 Posts
It's possible it could be some air in the system.
There is a function in vcds which can prime/bleed the fuel system after work has been done, depending on the system and what work has been done the requirements are 30 seconds to 3 minutes of pump activation.

Tech procedure states after changing fuel system parts, to bleed the system - start the engine - allow to idle for a few minutes - road test vehicle for over 20km - 'NOTE' if there is any air left in the system the engine will switch to limp mode - switch off engine - clear fault memory - continue road test - check for leaks - check error memory again.

Did you notice any metal shavings when you removed the imv? Just thinking if the hpfp is failing/wearing and there are shavings they could have contaminated/blocked your mates imv. Is there a filter gauze and a o-ring on the imv I can't remember.

I would advise if you outsource the work to specify no changing of parts unless they guarantee 100% it's gonna fix the problem. To many places (even dealers) will just throw your money at parts until it works.
 

·
Premium Member
Joined
·
233 Posts
It's possible it could be some air in the system.
There is a function in vcds which can prime/bleed the fuel system after work has been done, depending on the system and what work has been done the requirements are 30 seconds to 3 minutes of pump activation.

Tech procedure states after changing fuel system parts, to bleed the system - start the engine - allow to idle for a few minutes - road test vehicle for over 20km - 'NOTE' if there is any air left in the system the engine will switch to limp mode - switch off engine - clear fault memory - continue road test - check for leaks - check error memory again.
Will look into these. I did use VCDS to fire the pump up for about 30 secs the 2nd time when i re-swapped the IMV's. First time when the DRV's were swapped i just recycled the ignition for a minute.

Did you notice any metal shavings when you removed the imv? Just thinking if the hpfp is failing/wearing and there are shavings they could have contaminated/blocked your mates imv. Is there a filter gauze and a o-ring on the imv I can't remember.
No, both clean as a whistle, and I had a good look in both of them.

I would advise if you outsource the work to specify no changing of parts unless they guarantee 100% it's gonna fix the problem. To many places (even dealers) will just throw your money at parts until it works.
yes this is what I was worried about, I had been speaking to garages 6 months ago who wanted to swap the DRV as they suspected it was faulty, and would only use parts from TPS (£400) as opposed to the bosch ones on ebay for £100, and said there was no garauntee and the part couldn't be returned once fitted! which is why i never took it to them, but funnily enough it looks like that garage is my best bet at the minute.

I've actually found other threads on the internet about non genuine DRV's not working properly, I don't understand how the bosch ones on ebay look to be real, come in a bosch box, but are a quarter of the price of the TPS ones?
there are even cheaper ones with no name on them too....
 

·
Registered
Joined
·
26 Posts
I think you're only a multimeter, a few small crocodile clip leads and fuel pressure test kit away from finding the problem. Cost £30 if you aint got them. Test the in tank pump pressure to rule that out. Check/monitor voltage to fuel valve, pressure reg valve and sensor to rule power and bad wiring out.

The key word regarding the garage you mention is "suspect", they want to spend £400 of your money plus whatever labour they charge on a guess, if they guess wrong how much will the next guess cost? I've seen owners give up and sell their cars as scrap because of this approach. In the past couple of years I've had a bmw in which had £1500 spent on parts because of a blown fuse - 10p fix. A fiat £800 on parts because of a dodgy injector - £10 fix. A merc £1200 on parts because of a split alternator cable - £1 fix. I could go on..... all this because of no testing.
Regarding the quality of parts, I've used plenty of cheap parts and they're still good to this day ie egr valves, fuel pumps, injectors, solenoid valves. The only time I've ever had issues with cheapo's has been sensors, oil, cam, crank etc.
 
1 - 19 of 19 Posts
Top