Revs going flat?

[Tom DC2]

Hi all, recently when im acclerating the car revs up fine, then go's a bit flat when it gets to 3.5k through to 4k then is fine again all the way to vtec. I thought it might need a service so got that done last week and the issue is still there. Has anyone had any simular issues or can help me diagnose the problem. Its a JDM dc2. Thank you.

 

[muiris]

if it has an open air filter it may be suffering from heat soak which would cause a flat spot.

 

[Tom DC2]

It's got the standard air filter mate.

 

[ted]

check your plugs and leads... could cause this to happen

 

[Vtec6000]

Check ignition timing also

 

[Boyle]

I had the same sort of thing with my B16B. I changed my fuel to v power and that sorted it out for me

 

[VDM Motorsport]

Hi a customer once had this problem. we wired the car up to a simple air fuel ratio guage and it showed the car going to lean. Swapped fuel filter and it made it slightly better. Then checked the return line feed and it was not a constant flow. swapped fuel pump and it fixed the problem.
When a fuel filter is running in a constantly empty tank (as the customer was) it can start to damage the pump and hence lose flow rate.

 

[Tom DC2]

Thanks for the info everyone

Wear abouts are you based VDM?