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Flat spot on acceleration

Posted: 25 Jun 2019, 19:14
by 69gp225
Hello guys,

Need your help, since I’ve had my van there has been a flat spot, or should I a a hesitation
When I pull away. If I accelerate fast the van stutters but find once I’m away. If I take my time
And build my revs I don’t seem to get it.

I’ve replaced the plugs and leads, given it a service. What else do I need to look at?

86 1.9 dg engine. Running original peirburg carb.

Thanks Lee

Re: Flat spot on acceleration

Posted: 25 Jun 2019, 19:39
by 937carrera
Check the ignition timing and operation of the accelerator pump.

Re: Flat spot on acceleration

Posted: 25 Jun 2019, 20:00
by jrt
Plus check the vacuum advance,pull the pipe of and give it a suck and see if you can keep vacuum when putting your tongue over the end.If you can't and it's knackered it's an easy job to replace. Accelerator pump also easy to check and replace if knackered.
David.

Re: Flat spot on acceleration

Posted: 28 Jun 2019, 09:06
by 69gp225
Thanks guys,

were is the accelerator located in comparison to the carb, do you mean fuel pump?
cant seem to find in on heritage?

thanks Lee

Re: Flat spot on acceleration

Posted: 28 Jun 2019, 09:23
by 937carrera
Accelerator pump is on the side of the carb, square bit, 4 screws and a lever.

Lots of people find the page below and video useful

https://vwt25.blog/2016/09/15/pierburg- ... justments/

Re: Flat spot on acceleration

Posted: 28 Jun 2019, 10:11
by 69gp225
thank you will take a look tonight.

regards Lee