Fuelling or Electrical Problem ? HELP ! - catalogue of problems - now un-driveable

[beekeeper2003]

I have a 90BHP AHU engined 1998 Seat Ibiza Tdi. Recently, I encountered starting problems which I thought were related to worn glow plugs. These were found to be OK but apparantly there was no feed to them. Changed Glow Plug relay and temperature sender to no avail (glow plug light is not on for long enough - only a second or so from cold). Auto electrician said that the ECU swiches the earth to the glow plug relay and this was not happening. He put in manual earth switch to relay - allowed starting but definitely not right although despite assurance on glow plugs believe these must have been poor as car started OK when warm. New issue then appeared - starting very difficult but once started, ran OK although with more white smoke than previously HOWEVER, as soon as you lift off the throttle, engine refuses to rev up again until it has no load on it and is below 1000 rpm .... if you lift off throttle and then ask for power, engine does nothing until below 1,000 rpm and in intervening period (while guy behind you wonders what kind of jerk you are), car spews out enormous clouds of white un-burnt diesel smoke. Based on auto electricians comments and this new issue, decided to remove earth bypass to glow plug relay and buy a new (remanufactured) ECU. Fitted new ECU but no difference. Took car to SEAT dealer - diagnostics show no fault. Technican said replacement temperature sensor was wrong part and if replaced, together with glow plugs, he thought problem would disappear. Replaced temperature sender for 2nd time but held off glow plugs as sceptical and surprise surprise, the car is exactly the same whether hot or cold and glow plug light is still not on long enough. SEAT dealers next suggestion is a new engine !

The car has run perfectly until the starting problem occurred. It religiously has regular oil changes using fully synthetic oil at less than 10K milkes and it has always gone like a bomb. Something is in fault condition but no-one can find it . PLEASE help if you can.

 

[Rapido]

Can you get hold of Vag Com to check what is stored and measure current readings?

 

[Viking]

The glow plugs don't come on at all unless the outside temperature is below 9deg C (or something like that) so chasing that fault is pointless unless it's really cold outside.

 

[Viking]

Is it burning any oil?

 

[beekeeper2003]

No access to VAG com but assume (maybe wrongly) that SEAT dealers diagnostics would pick up any faults. Irrespective of outside air temperature, glow plug light is not on long enough, car does not start (can only start it now by towing it) and un-burnt diesel white smoke on overrun has to be seen to be believed

 

[beekeeper2003]

no - not burning oil (I'm not far from Richmond - Ripon)

 

[Viking]

When you turn the ignition on, the glow plug light will show briefly for a second or so as a sort of bulb check. This does not mean that the glow plugs are coming on. It has to be cold for the glowplugs to work. So, if the engine is warm the glowplugs don't work, and that won't affect the starting. Forget about the glowplug issue, as that's not the problem. Glowplugs only help it start, not do anything to assist in the running when it's started.

If it's not burning fuel properly then either you've lost fuel pressure (leaking injectors maybe, faulty fuel pump), you've lost compression somehow (dropped a valve or two, holed a piston or 2, broken piston rings, bent con rods) or the timing has slipped (injection timing or valve timing).

Not all of these will show a fault code in the ECU so unless the dealer has done some logs with the car running, they might not have any idea about what's gone wrong.

Edit: I was in Skelton on Ure yesterday.

 

[beekeeper2003]

Skelton very close. Once started, it will still do 90+ down the A1 as long as you don't slow down for anything so I don't think it's valves, pistons etc. The issue is getting it started and once started, never off the accelerator

 

[glynnd]

Could be a turbo fault, white smoke indicating total seal failure and difficult starting due to restricted air intake. Hope it is not this though, have you had the turbo intake pipe off to check the turbine is free and un damaged? If all is ok the only thing I can think of is fuel pump timing?
Glynn