Anybody dealt with the P00087 error code yet?

[S-M]

This was intermittent but is becoming more frequent, ecu detects fuel pressure is too low, puts it into limp mode, restart of the engine and everything is fine, sometimes for weeks.

So far i have changed the fuel filter (genuine filter) fuel rail pressure sensor (aftermarket Meyle) and the fuel rail relief valve (genuine delphi)

The problem still persists, i have swapped back to my original fuel rail pressure sensor for now with it being genuine.

The vcds log always says the rail pressure is 2-300bar under the specified target, when it happens.

I have bought a low miles (2023) lift pump to rule that out although i am putting off fitting it at the moment, i would like to properlly test the current lift pump, i think you can detach a fuel filter hose, run the pump for a min on vcds and measure the fuel output over time but i cant find the specs.

Any help?

 

[rod_vw]

If you are a registered VCDS user why not try asking on the Ross-Tech website?

Or perhaps some of the gurus on the T6 Forum.

 

[S-M]

Today i removed the fuel metering pump and checked for metallic particles, this was clean, although i will possibly need to research the metering pump a little more to rule out it being faulty.

Ross-tech forum is an option although i was hoping a dedicated forum like the old days would have some dedicated technical people to offer help.

 

[mmi]

Please share a full VCDS Auto-Scan and

VCDS engine blockmaps

1) ignition ON engine OFF​

2) engine idling​

How-to:
VCDS > Applications > Controller Channel Map

[Single Controller Address - 01]​

[Login - leave empty]​

[Function - Measuring Values ]​

[Output - CSV file]​

The result files: blockmap-01....CSV will be in folder C:\Ross-Tech\VCDS\Logs\....

The vcds log always says the rail pressure is 2-300bar under the specified target, when it happens.

Any more details under what conditions it happens - e.g. engine load., instantaneous injection durations. Does the pressure other times follow the specified or just lagging always?

 

[S-M]

Please share a full VCDS Auto-Scan and

VCDS engine blockmaps

1) ignition ON engine OFF​

2) engine idling​

How-to:
VCDS > Applications > Controller Channel Map

[Single Controller Address - 01]​

[Login - leave empty]​

[Function - Measuring Values ]​

[Output - CSV file]​

The result files: blockmap-01....CSV will be in folder C:\Ross-Tech\VCDS\Logs\....


Any more details under what conditions it happens - e.g. engine load., instantaneous injection durations. Does the pressure other times follow the specified or just lagging always

 

[S-M]

Hi, sorry just seen your reply, annoyingly yesterday i cleared all the codes while coding out my brake pad warning light, the van is currently sitting on the driveway with around 20 miles worth of fuel in it ready for me to swap out the lift pump from the tank on sunday with a bit of luck, its also booked in for all its belts/water pump etc etc on the 16th july and i`ve asked the guys to supply and fit a new HPFP while its all apart regardless (it has 208k miles on it)

The van is only used on weekends.

I will get the lift pump changed on sunday and take it out for a run to see if its either fixed or i`m able to post a VCDS full scan, thanks for the help.

 

[S-M]

Hi, today i dropped the tank to swap out the lift pump with a low mileage spare to rule it out, unfortuantly it apears that the lift pump was revised so my replacement did not fit, i did notice that the pump check valve on the bottom had x2 pieces of plastic swarf blocking the holes and wedging the check valve open, i have attached a pic of the valve on the replacement pump.
I am not sure how much of an effect this could have but my original pump has been cleared and refitted till another correct replacement can be delivered.

The van fired up as normal but i have not driven it yet as the fuel tank is still sitting on the ground under it, pointless refitting the tank to take it back off again in a couple of days.

 

[S-M]

pics

 

[S-M]

Hi, lift pump swapped, fault still occurs, here are the current logs as requested.

This week i found out the high pressure fuel lines are supposed to be a one time use part, the fault did initially show up after i had removed the fuel rail to exchange the glow plugs, i had initially went back in to check all the connections were tight, i have purchased a new set of high pressure pipes to replace this weekend just to rule it out, the fault occurs most often after driving for a while and under load on higher speed roads, if i potter around the local streets then its fine, it tends to happen when you need the power, tonight i drove the van to the fuel station, put in 10 litres to make sure the replacement lift pump sender operates then took it down the local dual carriageway, joining the flow it was fine, a spirited overrtake to 80 mph was fine, slowed down a bit to 60 and then tried accelerating in 6th gear, then the fault popped up.

 

[mmi]

Nothing obvious in the blockmap - a kind of expected as the fault appears at high engine load.
Checking return flow rate of injectors would be a logical step.

 

[S-M]

An intresting note, i fitted the new high pressure fuel lines yesterday, the top of the engine underneath was damp and oily, new lines in, jetwashed the top of the engine, drove it this morning on an MTB trip, it drove well but i was able to bring up the fault by accellerating from 55mph ish in 6th gear, while coasting down the dual carrigeway a quick key off and key back on to reset the fault and i drove the rest of the way avoiding low rpm high gear work and had no issues.

I have just performed the rosstech vcds fuel rail check procedure in the trail center car park, while idling i have around 330bar fuel pressure but witj the engine off i have 200, thats not aligning with what the rosstech video says is correct, apparently the pressure should rise due to heat soak with the ignition off?

I am going to log the "fuel high pressure: control deviation" values on the way home, the value fluctuates around +/-2bar at idle, the fault seems to occur around 250+ bar every time, not sure if thats a one off or its always laggy as you suggested.

Its still booked in for a new HPFP and its belts in a couple of weeks.

 

[mmi]

I have just performed the rosstech vcds fuel rail check procedure in the trail center car park, while idling i have around 330bar fuel pressure but witj the engine off i have 200, thats not aligning with what the rosstech video says is correct, apparently the pressure should rise due to heat soak with the ignition off?

The Ross-Tech video about fuel pressure I'm aware is direct injection petrol engine - which is a different story. Diesels purge pressure from rail in seconds when engine is stopped.

while idling i have around 330bar fuel pressure but witj the engine off i have 200,

In the picture the pressure engine off is actually plain 0 (actual value) - which is perfectly normal.

the top of the engine underneath was damp and oily

diesel?

Its still booked in for a new HPFP

Before throwing in expensive parts I still would check that there aren't any leaking injectors. One of the possible reasons for too low pressure at higher loads (=high fuel pressure) is an injector which gives up and the pressure escapes into injector's fuel return line.

 

[S-M]

The expensive parts list has already grown to be fair, even if the HPFP is "ok" i still want it changed due the current mileage (209k)
I have bought 4 new Injectors from PFJONES, these will be fitted by the garage when they do the belts and the HPFP
Due to the mileage i think its best to replace all 4, I will have the old injectors sent off for testing once they are out.

I did take a few screenshots of the laptop screen when using the VCDS scope feature to graph injector pressure nominal value vs actual, interestingly the old fuel metering valve seems to perform better than the new aftermarket replacement (i did back to back tests) but once your foot goes down and the pressures ramp up, the actual pressure drops off on both valves.