DaveySprocket
A2OC Donor
Okay thanks
1.4 Tdi Struggling to start..
- Thread starter DaveySprocket
- Start date
PlasticMac
Member
To have air in the return, when there is no air in the supply line, can only mean, (imo), air is getting in after the supply line joins the pump inlet.
Fuel after the actual pump, even within the pump body, is under pressure, and, (very), unlikely to vapourise, and form bubbles. But if it did, the bubbles are fuel vapour not air. Vapourised fuel would not get to the return line.
If their was a leak on the pressure side of the system, fuel would be leaking out. If that leak was within the injectors, then the leak would be into the combustion chamber, mixture too rich, smoke, etc.
If there was a leak anywhere else on the pressure side, air still cannot be drawn in while it's under pressure, (anything more than atmospheric). If pressure drops to zero, air can get in, but fuel must come out to make room for it, so it'd be visible.
We can see air in the return line, so there is a leak, which is allowing air to be drawn in. The leak is likely to be, (almost certainly imo), in the suction side of the pump.
Mac.
Fuel after the actual pump, even within the pump body, is under pressure, and, (very), unlikely to vapourise, and form bubbles. But if it did, the bubbles are fuel vapour not air. Vapourised fuel would not get to the return line.
If their was a leak on the pressure side of the system, fuel would be leaking out. If that leak was within the injectors, then the leak would be into the combustion chamber, mixture too rich, smoke, etc.
If there was a leak anywhere else on the pressure side, air still cannot be drawn in while it's under pressure, (anything more than atmospheric). If pressure drops to zero, air can get in, but fuel must come out to make room for it, so it'd be visible.
We can see air in the return line, so there is a leak, which is allowing air to be drawn in. The leak is likely to be, (almost certainly imo), in the suction side of the pump.
Mac.
DaveySprocket
A2OC Donor
Well I've ordered a new Elring gasket at least. Will see what happens when that arrives
DaveySprocket
A2OC Donor
I took the injectors out of my spare engine today, so I thought looking at them and where they go in the engine, might shed some light on how/if bad injector seals could let air into the fuel flow?
The hole near the top must be where fuel goes into the injector
In the head there are two holes, so I'm guessing one flow and one return.
I suppose if that top O ring wasn't perfectly sealed then air could get in there?
The hole near the top must be where fuel goes into the injector
In the head there are two holes, so I'm guessing one flow and one return.
I suppose if that top O ring wasn't perfectly sealed then air could get in there?
johnyfartbox
A2OC Donor
Any updates about the starting issues Davey?
The white one is still starting by the way.
The white one is still starting by the way.
DaveySprocket
A2OC Donor
Good to hear yours is still good!
Mine is still on the naughty step, I will get to it at the weekend hopefully. I'm just going to put the old Tandem Pump back on and see if that makes a difference.
DaveySprocket
A2OC Donor
Today I put the old pump back on with a new gasket (of course), bled everything through, and managed to get her started eventually, but she wasn't happy. As soon as the engine is stopped you can see air getting into the system from somewhere. I think I am done with this wee car, if anything I seem to be making the problem worse
I will put her in the classifieds and see if anyone wants to take her on..
I will put her in the classifieds and see if anyone wants to take her on..
johnyfartbox
A2OC Donor
Sorry to read that Davey.