Devon area help needed!

[willis 18 1 Cars]

Hi,

 

my 1.6 205 GTI hasn’t run for a while now. It turns over but doesn’t fire up. I got a new fuel pump relay a couple of years ago so don’t think it’s this... Fitted new spark plugs and checked fuel! Thinking it may be the fuel pump

itself, but I’m no engineer and don’t have test gear to diagnose.

 

If anyone is in the South Devon area (Torquay) and wouldn’t mind lending a hand to try and get it running again this would be much appreciated!

 

Thanks in advance 

[Callum 13 1 Cars]

I'm between cullompton and exmouth and work in Exeter so pretty close. Can you hear the fuel pump priming when on ignition 2? You could try removing the fuel line from where it goes into the Injector rail and try starting it if fuel sprays out you know the fuel pump is okay be careful removing the line as if its pressurised it could spray out. Something that might be worth doing is replacing the ecu temp sensor as I had an issue with mine where it wouldn't start due to the sensor not picking up the engine was cold. I'm still learning so my knowledge is limited but I have experience from faults I've had with mine that might come in handy 

[DamirGTI 342]

If it was left standing for longer period , might be stuck/sized fuel pump .. Modern unleaded fuel is good for maxi 6 months , after that it starts to degrade .

Stale fuel gums/turns into varnish , which coats the fuel pump roller cell mechanism thus it can't spin anymore .

Also , octane rating and "flash point" drops as the fuel ages making it harder to ignite .

 

I'd check the above first (fuel , drain and fill with fresh .. check if the fuel pump works/spins) .

 

 

Other , simple testing stuff you can do by yourself - use "easy start" spray for testing purpose :

 

- if it starts and runs on spray = then there's spark but no fuel

- if it doesn't start nor does it run on spray (not even a cough) = usually no spark , or can be both no spark and no fuel (to divide that further : take the plugs out and see if they're wet .. if so then there's fuel , so lacks just the spark)

 

 

D

Edited August 22, 2020 by DamirGTI

[willis 18 1 Cars]

Cool, thanks. You hear the fuel pump prime for around half a second. The car was started and used a bit up until around 18 months ago, then it wasn’t used very much ☹️
 

I used to run it on 98/99 but only filled it up a bit each time so never loads of fuel in there...

[jackherer 543]

16 hours ago, willis said:

You hear the fuel pump prime for around half a second.

I've seen the rubber hose thing between the fuel pump and the top of the fuel pump cradle totally dissolve due to the ethanol in modern fuel.

So it's possible your pump is working but the fuel it pumps is just going back into the tank.

 

Lift up the rear seat and take the rubber plug put then lift the pump cradle out of the tank so you can inspect it.

[willis 18 1 Cars]

On 8/23/2020 at 2:54 PM, jackherer said:

I've seen the rubber hose thing between the fuel pump and the top of the fuel pump cradle totally dissolve due to the ethanol in modern fuel.

So it's possible your pump is working but the fuel it pumps is just going back into the tank.

 

Lift up the rear seat and take the rubber plug put then lift the pump cradle out of the tank so you can inspect it.

So, I was having a play last night and just unplugged the fuel pump and also the plug under the smaller hole next to the fuel pump and it started! This maybe a coincidence, but just hopeful that a connection may have been slightly corroded somewhere?!? Anyway, thanks for the advice, we’ll see...

[Spesh 31 1 Cars]

On 8/22/2020 at 10:08 PM, DamirGTI said:

If it was left standing for longer period , might be stuck/sized fuel pump .. Modern unleaded fuel is good for maxi 6 months , after that it starts to degrade .

Stale fuel gums/turns into varnish , which coats the fuel pump roller cell mechanism thus it can't spin anymore .

Also , octane rating and "flash point" drops as the fuel ages making it harder to ignite .

 

 

Umm.. modern unleadeds are much more tolerant of storage than that, bit of an old wives tale I fear.

 

Also a drop in octane would make it easier to ignite and also if the flash point dropped (which it doesn't) that would also make it easier to ignite as it would flash to a vapour sooner.

 

Your correct that the octane would likely reduce over time but a couple of points as the ethanol content (5%) would flash off quicker than the base product but this would not stop the car starting.

 

The gumming you talk of is caused by the additives over time, not the gasoline nor the ethanol.

 

 

Biggest issue with modern gasolines is they tend to be hygroscopic so end up full of suspended water, Ethanol absorbs the water and, as ethanol is miscible with gasoline, distributes it amongst the final product.  Its a pain in the butt and is why unleadeds/supers are stored without ethanol and its injected at the time of loading onto a fuel truck.

 

(Source  - Its my job)

[Tom Fenton 1,541]

Interesting info. I've only once had a real problem with fuel going off, it manifested on a Mi16 engined car by a misfire under load above about 4000rpm.

 

£10 worth of fresh fuel and it completely cleared up.

[DamirGTI 342]

3 hours ago, Spesh said:

(Source  - Its my job)

 

Well , since English isn't my native language i often find myself "tricky" to express what i meant ... and often need to double check my writing gammas too . 

 

Might written it wrong i'm not the expert , the response is akin to make me feel to "defend myself for stupid act" but let's see if i can write what i really meant or kind of ... is , old past 6 months unleaded ethanol fuel will not be as volatile and able to vaporize as the fresh one ... thus stone cold engine will (kinda) struggle to ignite such stale fuel .

As you say , alcohol content doesn't help either "attracting" moisture over time and losing octane number being one of the octane booster agents in unleaded .

 

In the old days of leaded fuel , i really do not remember having such problems ... it was strong and stable fuel , much more resistant to degrading while storing for longer period .

The moderns stuff simply goes "sour" after 3 to 6 months ... i've lost count of the fuel pumps which sized stuck cause of the varnish from the stale unleaded fuel , and tanks full of some yellow gummy crap which once used to be 10-15l of unleaded fuel .

 

Once upon a time i took some odd 20l of leaded 98 fuel from an old car which was left standing for around 14 years if i remember - that fuel was still liquid , smelled just a tad stale but you could've still smell it "gave off vapor" and was perfectly fine for use still as i did , used it my car back then .

 

 

 

D

[Tom Fenton 1,541]

I think it’s worth pointing out that I think fuel in mainland Europe is very different to UK? Certainly when I’ve been over there to the Ring the super there had a markedly different smell to it. 

[DamirGTI 342]

Not sure (never been in the UK myself !) ... climate/ambient temp. wise , UK tends to be a bit colder and humid right , thus you might have more "winter blend" fuel during the year than the "summer blend" . But then again , Germany and northern EU is also colder climate areas thought the majority of the year ?!

 

One thing i know is , eastern EU (with no exception) has pretty poor fuel quality .

 

Over here certainly , as it's only one domestic oil corporation which has ("government blessing") monopoly producing and supplying entire country with fuel thus there's no competitors allowed (no "Shell" "Esso" "Agip" etc. pump stations over here) so they can mix what ever they like ...

When i fill up in Austria , Germany or Italy i can feel the engine runs much better/quieter , definitely goes better too , and full tank lasts longer (i can do more mileage) compared to what we have here locally . 

 

It's E5 unleaded currently here , at least that's what they saying ... though it wouldn't surprised me if it was more up to the E10 or even more sometimes during the year when they run out of the chemical/aromatics octane boosters .

 

D