A really odd one

**sierrafery** · 30th November 2014, 04:08 AM

Hi all, trying to help a friend through phone as he's far from me, he has hawkeye but unfortunately no oscilloscope, he is good at mechanics and handy with electrics

symptom: cranking but not starting, went well but in the morning started, ran rough then died, now just cranking without other effect

with spare known good ECM all the same

that's what he found with multimeter:

with the ECM plugged and measuring voltage between all the yellow and on the two common(0-85V) brown wires he gets 0.2 V with voltmeter(AC) while cranking, then with the plug to injector loom disconnected around 12-13V... i checked on mine to compare and i get 19 -20V(AC) on that plug but i didnt measure with that plug connected cos mine fires almost instantly and i can't see the voltage while cranking and i didnt want to remove the fuel pump relay and let it run out of fuel(his battery was on a charging robot all the time and enough voltage on it)

solenoid resistances checked with ohmeter and they all have around 1.6 ohm

no ECM related faul codes, gauge on pressure from the pump constantly all ok 4-5 bar, fuel is coming out well on the return while cranking, injectors are clicking with hawkeye

hawkeye reads engine speed while cranking up to 250 so i think crank sensor is OK

the only strange thing is that no MIL flashing after 5 - 6 throttles and no hissing sound in the engine bay nor with ignition off like mine does, he said he changed pump, filter housing everything...is it possible to mix something there?

so in a nutshell:
1. pump works, fuel pressure good, 4+ bar - fuel comes out on return while cranking
2. injectors are working on circuit test
3. engine speed 250rpm reading while cranking, no sign of smoke on the exhaust...NADA
4. same symptoms with spare ECM

5!!!!... no hissing sound or flashing MIL on purge procedure...silence, TP sensor outputs OK on live data

i'm burried in the diagrams but that thing for now is to odd to me... he said the timing is ok but i know nothing about that...the car just didnt want to start in the morning

any other ideas? :worry:

**jskerm** · 30th November 2014, 07:17 AM

Fuel check valve? Should be a valve that creates pressure in the rail on the return side. Is it stuck open?

**Graeme** · 30th November 2014, 07:28 AM

V8 or TD5? You haven't mentioned spark but hissing sound and purge procedure doesn't ring bells for a TD5.

**sierrafery** · 30th November 2014, 07:46 AM

Thanks guys for the replies, appreciate it,

@Graeme sorry i forgot to mention, Td5, for Td5 if you depress the throttle 5 times with ignition on ll the MIL starts flashing and there's a hissing sound comong from the FPR area, that's what i know for sure cos it's tested on mine but on his it's complete silence... i can manage with electronics but the engine behaviour is not my field

@jskerm , if you mean FPR(fuel pressure regulator) cos that's the only i know about it works cos all the pressures were checked in and around it.

i have oscilloscope but can't get to the guy to check so what's important to me to know is if there is any chance to measure the voltage with multimeter on the injectors and if it is what voltage should he expect there cos he said that between each yellow wire and the common brown ones it's about 0.2-0.3V (AC) while cranking...or any other idea

i'm thinking now that maybe a mouse gnawed something in the main engine harness cos the car stood near a barn full of corn over night...though near so much corn what mouse would be so dumb to chew some wiring

**simonmelb** · 30th November 2014, 08:21 AM

Hi,

My 2003 starts immediately 99.9% of the time, but very occasionally it cranks and no start.

Fix is to exit vehicle, lock with the remote, then unlock and it then starts right away.

No idea why but I suspect the ECU has not received the OK to start signal from the BCU?

Maybe worth a try if he hasn't already.

Good luck!

**sierrafery** · 30th November 2014, 08:33 AM

Hi, thanks for that, i've heard this happening to others too, couldn't find an explanation though... i'll pass him the info but iirc he's been locking/unlocking with key due to failed receiver for few weeks now

**Graeme** · 30th November 2014, 08:35 AM

I never encountered the 5 times throttle procedure during my 10 years of TD5 D2 ownership.

No oil at the ecu connectors I presume?

Disconnect the hose from the I/C to throttle body as a check that the airway isn't totally blocked.

Is it a D2A with its inlet throttle valve stuck closed?

A rat devoured all 3 MAP sensor wires on my D4's 3.0 in the harness over the back of the engine, but at least that produced a hard-on MAP sensor fault. Fortunately a repair could be effected with the body in-situ, although somewhat difficult being so far back under the windscreen.

**sierrafery** · 30th November 2014, 08:53 AM

It's 99 td5 manual and the EGR is bypassed, only fault codes ar for EGR and fuel temp sensor as there's a gauge instead of it.... the oddity is that not even a sign of smoke or smell on the exhaust, nothing, injector loom almost new

**ScotsD2** · 30th November 2014, 09:24 AM

If the fob is not being used to lock/unlock is the passive immobiliser selected in BCU they use the same receiver.

**Graeme** · 30th November 2014, 11:29 AM

Originally Posted by sierrafery

went well but in the morning started, ran rough then died....
fuel is coming out well on the return while cranking

If its not an immobiliser problem then being a '99, the fuel spill line from the injectors is internal so only accessible at the FPR. Hence I can't see how one can differenciate between fuel returned from the injectors and excess fuel being returned from the regulator. This opens the way for either the FPR having failed and not sending any fuel to the injectors or the gauze filter in the head behind the FPR to be blocked.

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