T4 transporter 2.5 tdi problem

[gph]

i have a 2.5 tdi transporter giving trouble with what seems to be either an electrical(relay) or lack of fuel supply.
the van has no problem starting when cold but as it warms up the idle fluctuates between very rough and normal. no problems driving but when up to working temperature can refuse to start, just turning over til battery flat.

Changed oil and filters and this seemed to cure the problem for about 1000 miles but has now returned and seems to be getting worse. The glow plug light also starts to flash when the rough idle kicks in. if left running the van can sound dead rough then suddenly sound as sweet as can be.baffled

Any ideas appreciated.

[paulb]

hav the diesel pump timing checked sounds like it out of spec

[frakkafield]

How many miles has the van done?

[gph]

the van has done 95000 miles. been with Vw garage now and changed pump and ecu. van at least starting now but is very dead since i got it back. on starting from cold she now sounds as if shes down a cylinder and will take no revs for about 30 seconds . dosent matter if you put foot to floor. on warm starting she turns over for a while sounding like shes fuel starved before kicking in. can the pump timing be checked on the computer without mechanical adjustment.

i've been lucky in that i bought this van of a friend who had just had all this work done by vw only for problem to return after 1000 miles so the recent work cost me nothing but the van is still not right. they seem to have nearly solved one problem and created another. the ignition coil light started to flash yesterday and i called with vw to tell me what it was. the young operative took the van and came back to tell me he had erased the fault but couldnt tell me what the fault was. i'm less than impressed with these "mechanics" and the customer service.

[t4 t0m]

Hiya

90% of the time, a flashing coil light which starts a few seconds after the engine is started and continues to flash until you turn of the ignition is caused by a faulty rear brake light or by a faulty rear brake light switch ... either should not cost anything much to repair ...

As for your lumping starting and idle issues, have you checked or had your injector nozzles recently? A bad spray from an injector will cause many of the symptoms you are describing, as will a bad timing setup. If you haven't changed your timing belt recently, and not changed timing, then my guess would be to check your injectors.

You can buy an synthetic injector cleaner liquid which may help to unblock them, but ultimately changing them will be a much better option! If your going to change them its worth upgrading them to a larger spary such as the .216 models which they install into the 150bhp T4's, combine this with a live ecu remap and thats how you end up with 156bhp like me :)

Hope that helps ...

//t0m

[gph]

the code for the problem is "fuel flow adjustment".the van starts perfectlywhen cold but when warmed up just turns and turns. has eventually been starting but its only a matter of time til she doesnt. have read this could be a fuel temperature sender problem.is this a big job?

[acetaylor]

this could be the governer on the fuel pump itself.

if not then as said before, just change the injector pipes on the head by the rocker cover (V cheep and easy to do)

check manual for exact whereabouts as i have an audi so will be slightly different.

good luck

ACE

[Rake]

Firstly - lets break this one down into its bits....

dont go replacing big expensive parts without checking the cheap and easy bits first.

Timing - check with VAG COM. and only at full operating temps.

Then - your fault code - check the pipe work as mentioned. Change the fuel filter - 5 mins and 15 quid. There is also IQ that can be checked too.

If your injectors are over 100K miles old - it might be worth replacing them with OEM or if you want more power - .216's (PM me I can help here) but dont go doing that till you know thats the problem....last thing you want is expence with no fix.

now other things that can cause this are MAF - this doesnt always give a fault code - disconnect it and see if she runs better or same.....if she runs the same then it could well be the MAF.

failing this take her to someone who knows the TDI's inside out like simon at central vw and audi in ellesmere port....

post back and let us know what you find !