1.5k to 2k rpm flatspot. EGR??

SriSte

When i bought my vectra it had a flatspot between 1500 and 2000 rpm.
A bit like it would start accelerating, get just over 1500 it would hold back then accelerate fully again once it got to 2000rpm. A bit like the accelerator pedal was being let off briefly.
Going up an steepish incline (yorkshire moors type incline :p) the car wont really accelerate while in that rpm band.

When i had the timing chain replaced and tech 2'd the flatspot disappeared. Fitted new plugs also.

Now around 800 miles later i can feel it coming back, although its not as bad as it was.... yet.
The flatspots currently smaller than it was, possibly doesn't feel to back off as much as it did.

Any suggestions? Could the egr system cause this?

The engine otherwise pulls smoothly, its covered 19,000 miles with a service every 2500 miles.

Many thanks
Ste

Matt

Have you removed the precat Ste? if you do a search for flatspot on here, you'll see several threads where the flat spot has been cured by removing the precat.

SriSte

Ahh so i see, cheers.
Maybe my flat spots just a bit lower then. Once its cleared 2k its pulls all the way up.

I hate working with exhausts, got a leaky exhaust gasket to sort, precat to remove and a new undercar heatshied to go on :p

daaaaavek

I felt changing to the 2.4l intake manifold helped removed that flat spot more than the pre-cat did .. does anyone agree?

SriSte

Glad ive got one on order then 🙂

My last 150 did feel a bit low on power around 3500rpm, but this one feels different, the car physically backs off for a bit, not just a lull in power.

I do think the lack of power my last one had isn't here with this one. Ive always felt it pulls harder all over the rev range, just not below 2k lol