16v jumping rpm gauge

[SimonJ]

hi my 91 16v hesitates and seems to have a lack of power when you pull off. The rpm also jumps when it hesitates. when you floor it the problem sometimes clears, but there is still an occasional blip. It's really annoying, anyone had the same problem?
The fuel pump also buzzes loudly all the time, I have a new one to try and a fuel filter to put in, but someone told me it could be the lift pump putting extra strain on the main one, any ideas guys?
cheers si

[GTIrl]

maybe your idle stabiliser valve needs a clean?

[SimonJ]

Hi mate I did that yesterday also cleaned the throttle body out, this helped make the car idle much more smoothly, there was a lot of dirt around the idle screw etc, but the problem still remains
cheers

[GTIrl]

id try replacing the fuel pump and fuel filter if you have one waiting to go on. I think you can check if your isv is working at all by turning the ignition on but not onto the starter, and if you hear the isv buzzing, its working. btw im a girl so you might wanna check im not giving you pants info!

[SimonJ]

i'm sure it isn't pants info anyway I need all the help i can get!

[monzablue16v]

You go girl good info!

Welcome to the forum Simonj.

It sounds like a fuelling problem dude if your pump is noisy and it hesitates and generally won't go then I would be changing the pump, accumulator and filter and maybe lift pump. You should hear the pump prime when you turn the ignition also.
Check your ISV by as GTIrl says seeing if it's buzzing when ignition is on and also by squeezing the airbox to ISV hose with your fingers to block the flow of air the car should die almost and then come back when you let go.
Other than that it could be well out on the tuning side like mine was I had loads of wierd problems before I had it RR tuned.
Keep us up to date and I'm sure everone else has their ideas too

[SimonJ]

I'll do the fuel pump on sat to see if that fixes prob, if not im getting cambelt done at vw specialist next week so may get them to have a look.
I'll check the isv but wouldn't the car be cutting out if this didn't wok?
Cheers for advice people will keep u up to date

[monzablue16v]

probably but not always lol they do weird things these ere old busses!!! worth a check just with it been when setting off and such sounds like the ISV is not catching the revs to stop them dropping or working intermittently. good luck

[SimonJ]

just went outside to check isv, i could here a buzzing from it when the ignition was on, but when i started car up and squeezed the hose the revs dropped only slightly, it didn't almost die, dont know if that means anything?

[rubjonny]

Check the lift pump before you replace the main one, if the lift pump goes it puts more strain on the main pump hence the loud buzzing.

Its under the plastic cap in the boot under the carpet, open it up and make sure you can hear it when the car is running.  You should be able to hear it faintly when your sat in the driver seat.

When I first got my GTI I could hear this faint buzzing noise with the stereo muted, at first I thought it was a problem with the stereo and I spent half an hour checking all the wiring till I realised it was the lift pump