flat spot - I've tried all sorts - any more ideas???

[toptotz]

I have a terrible flat spot on one of my cupra R's - I've tried all sorts to fix it but am at my wits end!

so far i've had the following done but to no avail:


New Boost Controller Sensor,
New Mass Air Flow Meter,
New Platinum Plugs,
also had it remapped to see if that would cure it but it hasn't - i've even had the map done twice to double check!!!

It's been linked up to see if there are any faults showing & it is showing no faults at all...

Please can anyone help as this is turning into a very expensive cure!

 

[Cowie]

Hi mate,dunno if it's worth a look but i had a flat spot on my 20VT at around 1500-2500 rpm,the car had to go in for a service and it was found that the breather pipes at the front of the engine,below the charge box had perished in a cpl of places,they were replaced and the car feels exactly as it did the day it was mapped,no flat spot and really lively again,must be worth a check.

 

[toptotz]

thanks for that, i've also had a set of silicone hoses fitted - would these breather pipes have been changed at this point?

 

[Cowie]

i really couldn't tell you mate,have you noticed any oil around these pipes,thats what got me to have them checked out.

 

[toptotz]

ok cheers - i'll have to get my fingernails dirty & get my head under the bonnet!

 

[Bishbash25]

I have noticed latley i have a split delay when i change through gears prob about half a sec before power kicks back in anyone have this issue.

 

[toptotz]

afraid not, just the flat spots to sort out at 2-3000RPM!

 

[toptotz]

although maybe i should mention that one of my LCR's has been set up so as to not let the revs drop at all during gear change - it's been played with by seat sport so i couldn't tell you what they've done but it has no lag at all being set up that way!

 

[edh]

Have you tried a throttle body clean and realignment?

Had similar problems with my Cupra and a new N75, N249, DV and also replaced 2 breather pipes which had split helped alot but the TB clean made the biggest difference on my Cupra and is completely smooth now, apparently it was pretty dirty and probably had never been done at 55k.

 

[toptotz]

do i have to take it off to clean it?

 

[edh]

Think you can get a spray and clean it without taking it off but the best way is probably to completely remove it. There's quite a few threads on here about it - I didn't do mine myself so I don't know what method was used on mine but it made a massive difference.

 

[toptotz]

thanks for that - i'll try n find some threads about it, still struggling to find my way around the site at the moment!

 

[toptotz]

MAF reading - anyone know what it should be?

hiya, just got my car back from having the boot lock replaced & i asked them to check the readings on the MAF as my car's just gained a bit of a flat spot at 2000RPM.
they said the reading came back at 4.6G/S & should be around 3.6G/S but they weren't sure if it was higher because it's been mapped or if this is a faulty MAF.

Any ideas???

 

[toptotz]

Just disconnected the MAF and been for a quick spin & the flat spot appears to have gone but still a bit lumpy - not sure i've done enough miles to be convinced its gone but will find out for certain tomorrow.

Does this reading mean it's getting too much air & not enough fuel or should it be higher because of the remap / induction etc???

 

[Feel]

If it's remapped, it should be more like 190 g/sec.

 

[Ruddmeister]

Remapped LCR max G/s will be 190-200

{Edit} too slow

That's at full chat in say 3rd gear

(non remapped car is 160-170g/s from memory)

 

[toptotz]

i take it that means my MAF if fooked?

 

[toptotz]

i think they've only checked this at idle speed - could that be why it came back at 4.6g/s?
i'm completely baffled - have they made a mistake with the reading, maybe?
but that wouldn't explain why they think it should be 3.6 tho

 

[ibizacupra]

log under load across rpm range at wide poen throttle in 3rd and see what max number you get
you cant readily judge a maf from its idle readings, so small a signal to differentiate

 

[toptotz]

ahhh - ok, thanks for that!