NO power under 2k rpm

adrian k · 05-07-2010, 06:54 PM

My S3 XR8 has developed a flat spot, and i mean flat spot when cold. so after letting car idle for a couple minutes each morning so melt the ice on the windows, i drive off and there is no power until revs hit 2000, i mean nothing, the more boot your give it the more it gurgles and slowly creeps to 2grand, then its off like a two stroke coming on pipe. 2-3kms down the road its fine. although it doesn't seem to have the same response from idle that it did a year ago. it does it summer and winter. Ford had the car all day Friday and can't fault it. I replaced the MAF sensor (another second hand one) at Xmas time and it behaved itself for a couple of weeks then back to the same.

Any ideas? TPS, temp sensor, squeeky cam sync, blocked jets, coils, leads, O2 sensors??
Any suggestions would be greatly appreciated, this is pis... me off.

Can stock bar HMS intake, K&N and full HMS SS zorst.

Windsor220 · 05-07-2010, 08:16 PM

This may be similar to what was happening with mine a while ago. When first started, a bit up the road would die down and then come back to life. After that it would be fine.

I ended up replacing 02 sensors and the fuel filter and its been fine since.

adrian k · 05-07-2010, 08:33 PM

Quote:

Originally Posted by adrian k

Can stock bar HMS intake, K&N and full HMS SS zorst.

Now in English

CAR is stock bar HMS ......

RG · 06-07-2010, 08:48 AM

Quote:

Originally Posted by adrian k

Now in English

CAR is stock bar HMS ......

I understood that anyway lol.

I'd be replacing the o2 sensors and the fuel filter for a start. How many k's has it done?

Dave_Obsession · 06-07-2010, 09:15 AM

Quote:

Originally Posted by adrian k

Ford had the car all day Friday and can't fault it.

Now why does this not surprise us.....

adrian k · 06-07-2010, 07:00 PM

Quote:

Originally Posted by RG

I understood that anyway lol.

I'd be replacing the o2 sensors and the fuel filter for a start. How many k's has it done?

It clicked over 80k on Friday (while Ford had it so a little ****ed i missed it clicking over :-)).
Interestingly today it felt much better, still flat, but no where near as bad as it has been. Ford said they cleaned the Maf element so whether that had anything to do with it i don't know.

I have another set of used sensors somewhere that i will stick in and see, reluctant to shell out for new ones unless i have to.

not sure if it makes any difference, but on the dyno it is super rich, but only richens up above 2k, the AFRs plumet to well below 10.

Windsor220 · 06-07-2010, 07:06 PM

Quote:

Originally Posted by adrian k

not sure if it makes any difference, but on the dyno it is super rich, but only richens up above 2k, the AFRs plumet to well below 10.

Thats normal for these things. Go ok until about 2500 and then the graph drops like a stone. If you get it tuned they will lean it out a bit.

jaym · 09-07-2010, 11:06 PM

Mines kindA similar just runs a bit rough till about 2000rpm :(