Skoda FELICIA 1.9 diesel (starting probs)

[saskia7]

Please help me my problem is that my felicia 1.9 diesel is very hard to start after it has been running. It starts fine when cold. i have replaced the glow plugs for new ones. i have put a new fuel filter in, and i have put a new heat sensor in( this is the sensor located nere the top of the engine. and simply plugs in and is retained by a plastic clip. As i said when the car has been used and is hot i can leave the car for say 10 mins then go back and it wont start, or rather it will eventually, but after like about 20 or so turn overs. but if i leave the car long enough for the glow plugs to function then it starts fine. Im at a complete loss as to what it can be. And im sure it must be something simple that can be fixed but WHAT? the car is a 1997 model estate. So please please any info would be great. Thanks.

Edited 9 September, 2008 by saskia7

[gazza25032]

Could possibly be that your diesel pump is buggered and needs replacing or rebiulding, this is a not hugely uncommon thing on the felly diesels.

[saskia7]

Ok ive been trawling through the treads to find some sort of answer. and the main answer could be a partial blockage along the fuel line some where. But i will put some additive in with my next refill.. Also ive just had another thought and some giudance would be useful. Is there a breather pipe near the fuel inlet somewhere. If so could this be blocked and would it have an effect on the fuel supply. Ive only said this because i have not seen it mentioned on any other thread. Any info most welcome.

[KenONeill]

This doesn't sound like a fuel supply blockage problem to me. If it was fuel supply or starvation you'd get a loss of power when you tried to accelerate hard, rather than iffy hot starting.

It might be an air leak that's only showing up when the engine is hot. Finding these can be a question of luck, and/or of playing around with petroleum jelly near joints.

Oh and kudos for being prepared to have a go yourself rather than look pathetic like my mum and sis try to do.

[saskia7]

OK KenONeill thanks for that, Now you might of stumbled on something here. I turned the fuel filter tap at the bottom of the filter, just to see if this helped and sure enough i heard some air coming out. and it did start a bit quicker. So in conlcusion it could be air related, but as you say it could be difficult to find. So Ken any other ideas on that one.

Oh thanks for the praise i do like to try a fix things myself as it can be costly otherwise.

[KenONeill]

I'm fairly sure it's airlocking now. Unfortunately the only way to find where the leak is is to be methodical or lucky. The most likely places are the fuel filter if it's a plastic in-line type, then joints, then plastic or rubber hose, then corroded metal fuel pipe.

[saskia7]

yeah im begining to think you are right, it is a plastic inline piece that goes into the top of the filter. it would most likely be there its taking in air from. maybe it needs seating in more securely. If it were a corroded fuel pipe i guess i would be losing fuel so. i think i will concentrate around the filter and see. Many thanks Ken. i was starting to think about weather it was actually the piston rings, but the performance is good and theres no smoke coming out. apart from the unburnt fuel on the eventual start from hot.

please feel fre to email me if you have any other ideas.

[email protected]

and once again many thanks for your help.

[KenONeill]

A new in-line filter's only a few pounds, and they're easy enough to change.

[saskia7]

OH I think we are talking about a different inline filter. i was talking about the plastic piece that fits into the top of the filter. effective it is in line as it has a pipe in and a pipe out but a plastic piece that goes into the top of the filter. do you know this bit??

[KenONeill]

Very much so; that sounds more like the moisture trap, and I know nothing about it on the Felicia other than what it does (traps water from the tank before it gets to the HP pump).

In general though, it's a suspect in itself even if it's not leaking air; leave it undrained long enough with bad enough diesel and it can kill the engine all by itself (by stopping the fuel flow).

[saskia7]

OK so my friend what's you final verdict on all the above info.... what do you think i should try ??

[KenONeill]

Start by draining the water trap, then, from what you've said, as a temporary measure to see if it's the problem, wrap it in clingfilm, and seal the edges/joints with insulating tape. If the problem goes away, at least you know where it is, and if it doesn't, you've probably isolated one thing that it's not.

[saskia7]

ok i will try that out tomorrow.. fingers crossed. i will report back my findings. cheers Ken

[TeflonTom]

i would try unplugging the coolant sensor to see if that makes any difference to hot starts

[saskia7]

Ok i will try that too, i just did not want to unplug thing in case i caused another problem, but i do have a new coolant sensor on there it has a green band round it.

[rigsby]

When it doesnt want to start, try removing the fuel filler cap, if you here a rush of air, it is probably the tank breather blocked and causing a vacuum in the tank, slowing the supply of fuel to the engine

[KenONeill]

I'd not thought of the tank breather, but like any other fuel flow starvation problem, I'd expect it to manifest after a given time, whether you'd parked up or tried to keep driving.

[saskia7]

yes i understand that one too. but does anybody know where the btreather pipe is so i can check it? Also would this be enough to affect the performance of the car other then the starting issue. because the performance is great. just this hot starting causing stress. keep the info comming it's all very welcome. Thanks everyone.

[KenONeill]

On most cars, the breather pipe runs parallel to the filler. As I say, I don't think it's the breather because fuel starvation tends to manifest as a lack of power, either generally or after a "fairly predictable to a regular driver of the car" time.

The last time I'd a breather issue, I resolved it by drilling a 1/16th diameter hole in the filler cap, and stopping filling when the tank triggered the pressure cutoff on the fuel pump.

[saskia7]

yeah thaanks Ken i thought it could be this as the pressure would dissapear after say an hour or so which would mean the engine was cool anyway so the glow plugs would work then. But if say i went ona journey that pressure would build up over the time then cause a vacumm from when i stop for 20 mins then try to start, this vacuum could be stopping the fuel from reaching the pump. Just enough to stop it from firing up i guess. That coupled with a slight airlock at the top of the filter could agrevate it also. I will cleanout the breather ppe today and see if i can make sure theres no air getting inot the top of the filter too. then give here run. What do you think Ken do you think we have found a reason for this happening??

[saskia7]

OK here are my findings the fuel filler breather runs from a box located bby the filler nozzle a black box with 3 pipes running from it 1 pipe runs down the path of the nozzle pipe and end just before the tank it has a little funnel shaped piece of plastic at the end.The pipe does not connect to anything so my asumption of that is it is a breather pipe. But on inspection it is free from blokage. the other 2 pipes run into 2 small rectangular chambers located to the front but on the inner side of the rear wheel arch filler side of course. i pressed theses pipes and both seems to be flexible and without blockage. So i then removed the fuel filter white plastic valve that is retained by a blue cilp. itcheck the seating of the valve and the rubber o ring that is on the filter. All ok. on replacement of the valve i put a small bend in the clip to press the valve down a little more. Then i run the car till it got hot.. waited 20 minutes and tried to sart her. But the same problem occurred would not start until the 15 - 20 turn. So back to square 1. i will also try the suggestion of removing the plug from the coolant sensor too and will let you know my finding on that one. Any other little gems of wisdom please pass my way as im running out of ideas now.

[KenONeill]

It sounds possible. What's throwing me slightly is that it just doesn't sounds like a typical fuel starvation problem.

[saskia7]

No you right if it were fuel starvation it would undobtably affect the performance. But the performance is great.

[saskia7]

Right How or why is this happening??? i unplugged the new green banded coolant sensor. and it started from hot. although the glow plugs did come on too. but it started. Is the green band sensor rated too high or too low?? why is it causing it to affect the starting from hot.

[KenONeill]

It's not impossible that the new sensor is defective.