Fuel pump/injectors

[MK R BOY]

Hi all

so my Leon cupra R has been bullet proof for 20 years, but now I’m running into starting issues.

to begin with she just stopped starting, turned out it was a fuel pump. I installed a new one from demon tweeks. This was fitted by an Indy garage and once running has never been so smooth.

but since the new fuel pump the start up of the car is a little bit of a struggle, she doesn’t fire straight away, almost like she is struggling to get fuel and then sometimes as she starts she is choking a bit, like she has a little too much fuel. She will normally turn over within 2-3 rotations But why would the starting be different suddenly?

speaking to the garage they want to flow test the injectors, is this sensible and cost effective?

is it likely the injectors are the culprit and would it be cheaper just to source four new ones and fit myself (Anyone done this? Looks straight forward)

thanks for hands on experience.

 

[Alexis27]

Your old pump might just have stuttered and damaged a seal on an injector.

I'd get them tested, just because you'll probably only need to change 1.

 

[MK R BOY]

hi alexis

I'm guessing they are not cheap then??

Is there a simple DIY check that could highlight a damaged injector? The indy garage I use are pretty good but they have done a couple of things recently that I really don't like and would prefer to sort myself if possible.

rgds

 

[Alexis27]

Not really I'm afraid. They have to go on a special rig.

theyre £80 new

https://oemandmore.co.uk/injector-18t-amk-bam-30311-p.asp

 

[Connor H]

Hi all

so my Leon cupra R has been bullet proof for 20 years, but now I’m running into starting issues.

to begin with she just stopped starting, turned out it was a fuel pump. I installed a new one from demon tweeks. This was fitted by an Indy garage and once running has never been so smooth.

but since the new fuel pump the start up of the car is a little bit of a struggle, she doesn’t fire straight away, almost like she is struggling to get fuel and then sometimes as she starts she is choking a bit, like she has a little too much fuel. She will normally turn over within 2-3 rotations But why would the starting be different suddenly?

speaking to the garage they want to flow test the injectors, is this sensible and cost effective?

is it likely the injectors are the culprit and would it be cheaper just to source four new ones and fit myself (Anyone done this? Looks straight forward)

thanks for hands on experience.

Check your fuel pressure when you prime the pump. If your new fuel pump came with anything other than those "ear" clamps they dont seal well enough to hold fuel pressure. I went through this for a year before finding out what the issue was, checked fuel pressure and after priming the fuel pressure dropped back to zero.

 

[MK R BOY]

Hi connor

thats an interesting idea. How exactly do I check my pump pressure and then fix it should it be the problem.

many thanks

 

[Connor H]

Hi connor

thats an interesting idea. How exactly do I check my pump pressure and then fix it should it be the problem.

many thanks

Pressure gauge and some fuel hose, plumb it in before the fuel rail. Pressure should hold after priming the fuel rail. i was also able to visually inspect the fuel pump by lifting it out far enough to see the fittings, and getting a mate to prime the pump. Fuel sprayed out the fittings.

I noticed in your other thread you bought an APS pump, thats the one that was supplied with jubilee clamps (at the time) which were my problem. I ended up replacing them with oetiker clamps which solved it the issue.

 

[MK R BOY]

I don’t have a pressure gauge, but I do have a bunch of those clamps.

how easy would it be for me to go in and replace the jubilee clamps with the oetiker ones?

would you have any pics/guides as to exactly what you did?

thanks.

 

[MK R BOY]

Hi Again

The only real picture I can find is from a Golf MKIV pump, i'm assuming the actual pump sits inside the white casing (you can just see the top in this picture)

Where about were your faulty jubilee clips? Is it the flexi pipe to the rear? you can just about see one oetiker clip??

 

[Connor H]

Hey

I don’t have a pressure gauge, but I do have a bunch of those clamps.

how easy would it be for me to go in and replace the jubilee clamps with the oetiker ones?

would you have any pics/guides as to exactly what you did?

thanks.

Yep its the flexihose that you need to worry about. just replace the clamps on it with oetiker clamps good and tight. If it worked then you'll hopefully improve your cold start issue. let us know

 

[Alexis27]

more info here

 

[Connor H]

Hey

Yep its the flexihose that you need to worry about. just replace the clamps on it with oetiker clamps good and tight. If it worked then you'll hopefully improve your cold start issue. let us know

how did you get on?

 

[MK R BOY]

not quite sorted it yet, Ive got the week off so ill try soon and report back.

 

[MK R BOY]

Hi Connor

So I've just finished the pump, and you were right that flexi had jubilee clips on. I replaced those with the OEM Audi Oetiker clips.

It was a pretty straight forward job, the only concern was there was another smaller flexi hose with no clips, but it looked much older and was on good and tight, I assumed it was the original and hadn't been touched during the pump replacement so I left it well alone.

The car started straight away and seemed to start pretty cleanly, Its had a run. Only time will tell for sure but honestly it felt a bit better and certainly hasn't made it worse.

Really wanted to thank you for offering your experience and help bud.

Rgds

 

[Connor H]

Hi Connor

So I've just finished the pump, and you were right that flexi had jubilee clips on. I replaced those with the OEM Audi Oetiker clips.

It was a pretty straight forward job, the only concern was there was another smaller flexi hose with no clips, but it looked much older and was on good and tight, I assumed it was the original and hadn't been touched during the pump replacement so I left it well alone.

The car started straight away and seemed to start pretty cleanly, Its had a run. Only time will tell for sure but honestly it felt a bit better and certainly hasn't made it worse.

Really wanted to thank you for offering your experience and help bud.

Rgds

hey buddy,

no problem and im glad it worked. It took me a year during the pandemic to figure it out myself so i tell literally anyone whos changed their pump and has this issue.

The other pipe is just a fuel return line i believe so that doesnt matter, plus as you say its been heat shrinked to it pretty damn tight.

ATB

 

[MK R BOY]

so four days and she is back to her old self.

Job done I would say!!

thanks again