Starting problems
 

Looking for help and pointers on this please.

Starting problem Hyundai Santa Fe 2002 2L CRDi diesel.
Serviced every 10K Km’s,. 222k km’s.
Never involved in any accidents.


Problem started off when cold would not start, initially only when cold or left overnight.
However the problem evolved over two months to would not start when hot.
Once running car runs perfectly.

The car will bump start easily at any time. Hot or cold.
It cranks fine, not sluggish at all

If battery is boost charged seems to eventually start a bit easier.

Things done :-

ODB tested, no error codes.
Jump starting does not work.
Using jump leads to connect directly from battery to chassis and fusebox live feed.
Main fuses all cleaned up and ok
Glow plugs tested ok (new jan 2015)
Battery tested with full load tester, ok.
Glow plug relay changed
ECU relay had dirty contact, cleaned and also tested with other relay.
Water temp sensor, reading correctly.
Air temp sensor reading correctly.
Fuel pump pressure ok
Injector pump pressure, high pressure rail, ok
Fuel Injectors tested, 2 tips changed as pattern a little off.
Fuel lines tested and couple of small leaks found on return feed.
One way valve fitted before fuel filter to stop any fuel returning to tank on delivery line.
Fuel tank removed and a washer replaced where small amount air was getting into pipe.
Starter motor changed.
Crank shaft sensor changed.

Not sure about this, have heard that sometimes the cam sensor is used to help start the engine.
When push start, this will by pass the cam sensor and go right to using the crank sensor thus enable starting from push start
When cranking to start, the faulty cam sensor will prevent the engine from firing up.
As I said, not sure about this.

Good luck

Thanks

I will look at this and see if its that.

I am currently having the same problem with my 2003 Santa Fe CRDi automatic. The only way I can get it started is with brake cleaner in the intercooler hose (won't bump as auto).

Last night I carried out a diesel injector "leak off" test and that has shown that one of my injectors is leaking off far too much diesel.

I plan on replacing this injector at the end of the month and see if it makes a difference.

I hope this helps and I'll keep you informed with what happens next!

The saga continues unfortunately.

My injectors were tested and though 2 tips changed as slightly misfiring the problem continues.

The cam shaft sensor was changed
Crank shaft sensor changed.

Leaks in the return pipe fixed (only leaked when under pressure, which normal can't happen).

Fuel tank removed and seals changed.

The problem now is each time something is done, it works for 24 hours but then fails again.

Problem I now think is in engine wiring harness as this gets disturbed when things are done. The injectors are NOT getting the fire signal when cranking.

Bumping is still fine.

Haha! Mine does exactly the same! Every time I have moved the injectors around or replaced the injector seals, it seems to fix it for 24 hours and then goes back to normal!

I still maintain that there is a vacuum leak/air leak on your fuel system. The CRDi engine require many thousands of pounds of pressure to fire the vehicle but significantly less pressure to actually run it. The only thing you can do is keep plugging away at it.

I had the same problem on a Vito van 2.2CDI which had a very similar high pressure setup. I replaced the leak off pipes, injector seals, high pressure fuel pump and all sorts, eventually I replaced the fuel pressure regulator 'O' ring (£12 from Mercedes) and never had another starting issue with it ever again!

When you say the injectors have been tested, what test did they do? I carried out a leak off test on mine (see pic below) and it shows that injector 2 is leaking off far too much diesel even when engine is cranking hence fuel system not getting up to the correct pressure.

When I replace that injector, I will be removing all of the injectors, re-cutting the injector seats and replacing the injector seals again just to remove this being a potential problem.

Hope all this helps.

Thanks Ian

The injectors were tested by an diesel testing company and other than 2 tips were ok.
They are firing correctly and have correct pattern.
The whole fuel system has been pressure tested and vacuum tested and appears ok.

One thing is odd, yesterday the car started ok, the air temperature has been around 20deg which is un seasonally high.

Next week temps are supposed to be half of that and sub zero over night.

All the glow plugs have been tested and are ok.

When it does not start it is not getting the firing signal at the injectors so I think its an electrical issue rather than fuel (hence reason why cam/crank sensors changed).

The water temp sensor is reading correctly.

So its all confusing at present.

Update on this.

Hopefully fault now found.

The engine wiring harness where it goes into the cabin, some of the cables & the ECU +ve cable were chaffed and shorting out.

Why it would chaff I am not sure but those bits repaired and it seems ok (fingers crossed)