Starting problems

[mahon257]

Looking for some informed guesses to help diagnose an intermittent starting problem.

Disco is a 1996 300 TDi.

In last couple of weeks the car has developed an intermittent behaviour, where it refuses to start. The engine turns over on the starter motor just fine, no odd noises etc...

It either starts on the 1st turn of the key (immediately), or refuses to start, even if I leave it turning over on the starter motor for over 1 minute!. I can come back to the car 30 minutes later, and it'll be fine, and start immediately. Once it's running, it's fine, pulls like a train, as usual

It has happened when the car is completely cold (1st run of the day), or hot - after a short drive somewhere.

Here's what I think its not:

• High Lift pump - it's mechanical - so it either works, or doesn't (presumably)
  
• Bosch fuel pump, again, I would have thought it either works or doesn't
  
• Alarm/Immobiliser related - when the immobiliser kicks in - normally can't turn over engine on starter - that's not happening here.
  

What it might be (my guesses):

• Fuel Cut-off solenoid? (dodgy connection)
  
• Air in fuels lines (but why would that be intermittent?
  

Any help advice much appreciated..

Thanks

Nick

[mahon257]

I might have found the answer. thank you Youtube!!! (and "trailerfitter2")...

things to look at / test:

• immobiliser
  
• glow plug relay
  
• cut-off solenoid
  

[mahon257]

dang it... anyone know how to diagnose (test) a tamper proof cut-off solenoid?

[mahon257]

It's not the spider.... Just taken the dash apart - and I don't have one! Realised now my car is the Manual 300TDi "EDC" variant. Ordering a relay "PRC6913" (glow plugs/cut off solenoid).

[mahon257]

Replaced Glow Plug relay with new one (PART NO: PRC6913) - no effect on underlying issue. Broke down again. Called the AA. . AA cracked open one of the injectors pipes at the head end, - no fuel getting to cyclinders... car just turns over on starter.

Next time I get some time to look at this plan to: will crack banjo (feed pipe) on injector to prove fuel getting from tank, fuel filter, high lift pump. If still getting fuel to injector... looking strongly like the f'ng tamper proof cut-off solenoid. I don't expect anyone will give me advice on how to remove this (publicly), but if anyone following this would appreciate some advice via PM on how hard it is to remove the solenoid with the pump still attached to engine... (please! beg beg please!) - or should I just remove the pump and then hack it to pieces?

I'm suspecting the solenoid... as when you do eventually manage to get it running... it runs just fine - the only issue is starting the car. I don't even want to think about the EDC (ECU?) - just called JSF for a quote - £1,500 + VAT.

Final thought... does a "normal" single wire solenoid fit this pump? I'd like to jerry rig a 12v feed from the ignition barrel direct to solenoid if possible.

[mahon257]

Still can't start the car when up to running temp (fine when cold). Am getting fuel to pump (I cracked open the banjo on the Bosch pump - get fuel jetting out when turn engine on starter).

Does anyone know... where this relay might be... see pic (part AFU2913L) - I think it powers the Cut-off solenoid on my car - which seems to be the problem... (either the solenoid or the 3 wire anti-tamper circuit that covers the solenoid).

I've bought the relay (£40 genuine part) - just looking for somewhere to put it LOL

It is not: Under driver side kick plate (plastic cover on floor) - which seems to be where Microcat suggests it should be... in fact the whole top row oof relays are not present.. weird.

Also, it ain't in the engine bay, and not under PAX glovebox either. Baffled!

[mahon257]

Have at last, isolated the problem.. (as can reproduce the issue when engine at running temp - doesn't occur when cold). The problem is the electronics within the Anti-tamper cover on the Fuel Pump - believe its called the "DDS" (not sure).

Having tw*ted the DDS with a chisel+hammer a few times - (always a sensible approach with delicate electronics I find), it actually seems to be fixed! In the meantime have ordered this Timing kit from Paddocks, so will have a go at a permanent fix by first removing the Bosch fuel pump then try to figure out a way of permanently removing the DDS. I'll then direct wiring the cut-off solenoid to the middle of the 3 wires on the loom - that go to the DDS (have found this wire has 12v when immobilser de-armed on key fob, and ignition at position 2)

[mahon257]

Have at last, isolated the problem.. (as can reproduce the issue when engine at running temp - doesn't occur when cold). The problem is the electronics within the Anti-tamper cover on the Fuel Pump - believe its called the "DDS" (not sure).

Having tw*ted the DDS with a chisel+hammer a few times - (always a sensible approach with delicate electronics I find), it actually seems to be fixed! In the meantime have ordered this Timing kit from Paddocks, so will have a go at a permanent fix by first removing the Bosch fuel pump then try to figure out a way of permanently removing the DDS. I'll then direct wire the cut-off solenoid to the middle of the 3 wires on the loom - that go to the DDS (have found this wire has 12v when immobilser de-armed on key fob, and ignition barrel at position 2).

Plan to remove the DDS as don't think you can actually buy them anymore... maybe someone can correct me on that?

[mahon257]

have just bought this timing kit from paddocks. plan to remove pump and put the dds in the bin.

[Landowner]

Lets know how you go on because mine is the same 3 wire model as yours and I am having starting problems which I believe are related to the security device on the pump.

Might tw*t mine off tomorrow

[mahon257]

Lets know how you go on because mine is the same 3 wire model as yours and I am having starting problems which I believe are related to the security device on the pump.

Might tw*t mine off tomorrow

I'll gladly let you know when I've removed my DDS... but it won't be a for a couple of weeks... It's made of granite this thing... so hopefully will be able to remove it at some point!