T4 Fuel Faults - Not listed in workshop manuals...?

[beardface]

I've had my T4 for a year now. It's such a lovely car when it runs. And it's a great camper.

But right now it's marooned in the driveway.

My current issue is:
I have a fully charged battery.
I have just replaced: Ignition leads & Starter Motor.
I have this year replaced: Alternator & Ignition Coil, 167 Relay.

I can get it to crank, but I'm not getting ignition. I've taken the ignition leads off and have seen that they have sparks in them (tracing back to earth).

I am now thinking I have a fuel fault.

Over the past year I have bought both the white Peter Russek Workshop Manual and the green Brooklands Manual.

In the fault finding section, both of them list 'Engine cranks but will not start' and both refer to #5. Faults in the fuel system. Refer to "Fuel Faults".

BUT NEITHER BOOK HAS A SECTION ON FUEL FAULTS ?!!

I am at my wits end.

I have hooked up VagCom (albeit a Lite Version). The only fault I get in the engine is an immobiliser fault, and when i check the immobiliser section, i only get the 'key signal weak' fault.

Will VagCom find a fault in the fuel system, such as a faulty fuel pump?

Does anyone have a fuel fault section in their manuals?

[Sunny43.5]

Just a thought you described a fault with key and immobilzer , when I did a complete engine transplant on my sons van we had the same issue I spent four days trying to get the thing started as we had used the engine from a donor van we found holding the other keys next to the ignition barrel it started first time Grrr so maybe the transponder in the key is at fault maybe a locksmith can recode a new key for you .

[beardface]

I'm beginning to think it's a blown head gasket.
I might have to call in the troops.

[jamesdavid]

In regards to your question, i highly doubt it, unless there is an open circuit/open loop in the system then it may identify it. You can always take the intake pipe off of the filter box, so you have a straight path to the intake of the engine, i.e no air filter and spray brake cleaner or some other form of 'aerostart' "easily ignitable" fuel into the air ducting while someone cranks the engine. If the engines fires there is a good chance you have a fuel supply concern. (It is a crude way, but its effective and quick) Don't do that on a diesel, ever, lol. You can also disconnect the supply pipe from the tank to the engine, hook up a hose and run it into a bucket and crank the engine, that way you will know if your lift pump is working (blue pipe or a pipe with a blue mark is usually return so leave that connected)

As i work with Volkswagen i will ask the guys tomorrow if there is something specific that you should look at.

Also i would recommend double checking your earths for the ignition system as the spark may be too weak and the above test will not rule out a bad earth. Check your spark plugs, i.e not oil soaked etc and if possible use a spark plug tester to confirm spark. If you have easy access to a noid light kit you could also check injection pulse on your injectors.

Hope this gives you something to go on.

[supclean]

Dont pannick yet
For a no start condition First of all varify the spark pulse
what we are looking for is a good strong spark and pulse consistancy
Loosen spark plug caps from two plugs, whilst turning motor over with a pair of plies pull spark plug cap away from plug around 13mm
Listen for a strong spark and an even pulse
If all good this rules out cap, rotor & coil
Next turn key on and listen for the fuel pump to prime up Should take two or three seconds
If all good this should tell us that we are getting fuel rail
Next thing is to follow James David suggestion & spray some aerosart or something similar down the intake whilst turning the motor over and see if motor fires
If it fires then the next thing we need to do is check to see if we have power at the the fuel injectors
Hope this helps

[Sunny43.5]

I still think he needs to check the key thing as we found all things in our van were fine fuel electrics etc but the kicker was the damn key .

[supclean]

I am not sure exactly how the immo works, whether it interupts fuel and spark or just fuel
He mentioned that he has spark so I thought next varify that he has fuel pressure at the rail and that the injectors are firing
If so this would rule out the immo
The Vag Lite code mentioned low B+ at the immo This sometimes means that the battery has been low or dissconnected

[ix_Xafra]

I am not sure exactly how the immo works, whether it interupts fuel and spark or just fuel
He mentioned that he has spark so I thought next varify that he has fuel pressure at the rail and that the injectors are firing
If so this would rule out the immo
The Vag Lite code mentioned low B+ at the immo This sometimes means that the battery has been low or dissconnected

Had this problem with my T4 many times. It would just refuse to start and without explanation would start again. Happened one time while in for repairs at a dealer and their experienced tech was away that friday.

Monday morning he had it going in minutes.

There was a dry joint in the wiring on the back of the relay panel. The relay for the fuel pump, not sure what number relay.
Seeing as he picked it up pretty quick I assume it's a common fault.....

[jamesdavid]

Relays can be a common cause of a no start fault on a transporter. Also the hall effect sensor in the dizzy can cause a no start, but this usually is a intermittent fault, i.e it will start sometimes and other times will refuse to, usually when its hot it is harder to start, once it has cooled it should start again. I believe engine speed sensors can be a culprit too but i would think it would throw a fault code for intermittent or implausible engine speed signal.

[Sunny43.5]

Jimmy Mac was the one who solved our T4 ,s non start but I did forget to mention that after the transplant my sons van which was originaly diesel powered started with its own keys etc . The old diesel engine was fitted back into the donor for resale and it was this one that would not start as . Jim told me about the key immobilizer and all we did was hold the my sons key next to the donor vans keys in the barrell and it started so I had the old keys code copied and then sent to the other keys problem solved . Its worth a try the recode only cost $20 .