Engine Misfire/hesitation

[Telf 224 2 Cars]

I've been having a few issues with my 1.4 GR. It hesitates sometimes with light or sometimes heavy throttle. The carb has been removed and serviced.

 

I cant see any issues with the engine - not using coolant, oil ok, not milky etc.

 

I think the fuel pump may be broken as there doesn't appear to be much fuel in the filter - although the car weirdly does run.

 

have a look at the video linked - there is only a bit of fuel in the filter housing it seems. I'm presuming this isn't how it should be? ( may hand in the video is on the feed side from the fuel tank)

 

https://youtu.be/26BpsIpgr_8

 

any help much appreciated

 

 

[Telf 224 2 Cars]

ive been having a look a fleabay. Its seems my GR's fuel pump is actually in the engine bay- this is a new one on me! I thought they all used the same tank pump that you find in a GTI etc...

 

Time to break out the workshop manual!

[jackherer 543]

Is the fuel pump bolted to the cyl head and driven by an extra lobe on the cam? If it is that type apparently the dedicated cam lobe can wear on some cars, I'm not sure about TU engines though? If it's the pump I think they are very cheap and they are certainly easy to replace.

[Telf 224 2 Cars]

I don't think its driven by the cam- its just forward of the top of the cam cover- will have a check in a bit- no sure about that fuel quantity in the filter bowl- that cant be right?

[Telf 224 2 Cars]

so I've changed the filter - it now starts 1st turn of the key - an improvement!

 

But its still puttering and hesitating- I'm guessing maybe the pump but also the carb not set up right?

[burr_2000 1]

I'm sure these use a mechanical pump driven off cam

Edited April 12, 2016 by burr_2000

[Tom Fenton 1,542]

Mechanical fuel pumps either work or don't work in my experience. Yours is working by the sound ot it and you need to look at the carb.

[Telf 224 2 Cars]

Hey Tom.

 

I tested the flow out of the pump to the carb - its fine.

 

As Ive posted before I stripped the carb and replaced all the various components so I'm not really sure what more to do.

 

I'm acutely aware I may not have set it up right but as far as I can tell there is only 1 adjustment screw

 

the carb fitted is a sole 34PBISA

[Telf 224 2 Cars]

well I think it is!

 

I will go take a picture of it

[Telf 224 2 Cars]

the 1 adjustment screw arrowed

 

 

[Telf 224 2 Cars]

Ive stripped this again and submerged all the parts in cola for an evening- fizzing like barmy- hopefully it will clean it all up and make it work better!

[Telf 224 2 Cars]

Update!

 

Parts removed from Cola. Rinsed with hot water- to get rid of sugar/coke. Rinsed in Carb cleaner and reassembled.

 

Carb refitted - Hesitation gone!

 

 

Hooray!

[Telf 224 2 Cars]

As in my GR project thread- this fault has returned again- really stumped now!