The PD diesel does not have a tank mounted lift pump; the camshaft driven tandem pump performs this function.
659.
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if it's a PD engine then it will be the seals for the injectors not being replace when the head was done. these seal seal the high pressure from the low (return).
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And if the garage didn't replace the bolts holding the injectors in one's probably come loose.
Has the oil level risen?
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you want to hope there not loose as it will damage the head (it goes oval) and even with new seals it wouldn't seal so it's new head time.
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Hi Guys,
The car IS STILL in the garage, so far the mech has checked all of the injectors which were working fine.He has then by passed the fuel pump on the engine with a lift pump which appeared to do the trick however he had the same problem several hours later and still could not get it started..
He then contacted VW who said that the pump in the fuel tank was probably faulty,on getting into the tank he found it did not have the pump fitted,Apparently my car (2001) was some kind of prototype whereby VW,in that year messed about with different fuel pump designs.The mech also tested a fuel relay under the dash which tested okay.
The deisel fuel was checked and found to be okay and not polluted,the mech is now at his wits end trying to find the cause (and so am I!!),speaking on the phone on Monday he made passing mention of a non return valve on the fuel line and that he was going to have a look at it !!.
The mech has checked just about everything on the car connected with the fuel problem but he just cannot make any progress.
Sorry to be a pain gents but ANY ideas????.
Regards Nighthawk.
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Coolant temperature sensor? If faulty(or disturbed after head gasket) the ECU could presume that the engine is up to temperature and the glow plugs won't be energised? (hence easystart helping)
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So VW don't know that this car doesn't have a tank mounted lift pump? It really makes you wonder about VAG's representation in the UK.
The point made about the unit injector seals and the clamp bolts (once only use) was a good one. This can be checked for validity by measuring the transfer pressure, ie the output pressure of the tandem pump. This test would also verify that the tandem pump is delivering fuel to the specified pressure.
Concentrate your searches on the items worked on when the head was removed - something was probably incorrectly fitted or damaged.
The general history of this case indicates to me that the vehicle is being worked on by people who do not appreciate the finer points of this sophisticated engine. Therefore go carefully - it's a good unit, easily damaged.
659.
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Hi Gents,
Thanks to all that have replied;the mech, accepting there is no lift pump ,has now moved away from the fuel tank and today replaced the none return valve,the engine started but still needed to be cranked over a lot before firing.
He has now clamped off both the forward and return fuel pipes on the fuel filter and said he will leave it overnight to see if the engine will start okay in the morning,this will apparently show if there is a pressure loss.
He also mentioned and showed me a sealed fuel filter unit (£180!) which he had ordered in case the one in the engine is faulty.He says that he is reluctant to fit it at this time as it cannot be returned to the parts warehouse if he fits it and it does not solve the problem.
I will (hopefully) know more tomorrow.
regards
Nighthawk.
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Closing off the flow and return lines to the fuel filter will achieve nothing and prove nothing. On PD engines, the fuel filter is between the tank and the tandem pump fuel inlet and consequently runs at negative pressure. The fuel return from the gallery in the head flows via the "T" piece on the fuel filter which contains a heat sensor. When the fuel is very cold, the heated fuel from the gallery returns to the filter cannister in order to minimise the risk of waxing; when it's hot it goes back directly to the tank to maximise fuel cooling.
I'm afraid I have serious doubts about your mechanic's understanding of the fuel system on this car - there is no "fuel rail" and it doesn't hold any pressure. The output of the tandem pump must reach a defined pressure whilst cranking so that fuel will flow adequately into the unit injectors.
This sort of problem is almost impossible to diagnose at a distance, but one final shot. If your engine is a type AWX (see paper label on cambelt cover), check the fuel inlet hose to the transfer pump for rubbing through. Near the tandem pump inlet, the fuel hose runs along the underside of the charge air pipe which connects to the EGR/anti-shudder valve. There is a bad fret here and the pipe can rub through. If there is a pinhole leak, the tandem pump will suck air and the engine won't start. You need to disconnect the charge air pipe at the EGR and move it up a bit to see this problem.
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Hi
Have they pulled the injectors back out? if it's not sealing you will see marks on the injectors (dark and light marks)
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Hi,
Sounds like the injection pump timing is out by a few degrees. This can cause the engine to start fine when its cold (when extra fuel is injected), but to really strugle to start when its warm or not start at all. Did you find the car to be a little sluggish before hand?
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PD diesels don't have an injection pump.
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Nighthawk, did you solve the problem, it sounds like I am having exactly the same problem with my 2000 Golf 115bhp PD (AJM), (this doesn't have the lift pump either) I am about to tackle the injector seals as I have changed the tandem pump, filter and control valve.
Any help would be appreciated.
Thanks Dave
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I have a similar problem to nighthawk. Passat 1.9 tdi pd 2000. If I park it facing uphill (only slightly uphill will do it) After 2 days the engine fires and dies immediately. I then have to crank for some time (sometimes I have to recharge the battery and crank some more). It then fires and runs perfectly.
Park it on level ground or downhill there are no problems. Left it at the airport for 3 weeks on level ground. It started first time.
If the front wheels are even 3-4 inched higher than the rear after 2 days the problem returns. Tried clamping fuel pipes to prevent draining back to tank. Same problem. There does not seem to be any fuel leaks.
Highest point of the fuel system is the Tandem Pump. This might be most sensitive to the uphill parking issue.
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I have the same problem now. 2001 TDI Passat. If parked uphill it takes long to get it running. Otherwise no problems. Did any of you find a solution to this problem yet?
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Hi, Nighthawk, Oldguy and Frye.
Did any of you solve this problem. I have exactly the same problem, and it is driving me mad... Can't figure out what causes it.
Funny thing is that I also have a problem with coolant disappearing, just like Night Hawk originally had, and the first time I noticed this was the day before the first time the start problems occurred.... any connection here?
Edited by Nitrox21diver on 10/01/2012 at 14:08
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Hi,
Suffering from exactly the same problem. My mechanic is about to start trying to fix it. Would love to save him the heartbreak (and me the cost!) of wrong solutions. Can you please, please, please, let me know what the problem was with yours?
Thanks, Lisa
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