PEAKING AT 4800rpm???

[Anonymous]

Hey guys, i'm from South Africa and i own a Nissan Sabre (South African derivative of Pulsar). i recently installed a SR20DET, after market management and FMIC. It has a standard 5 speed SR20 box and is FWD. It makes 140kW (+-195bhp) at the front wheels, BUT AT 4800rpm :? ??! I've tried messing with the management, but no dice. I've also installed a larger fuel pump. The motor isn't getting fuel after 4800rpm and when i give it a boot there's a strong petrol/fuel smell. i'd appreciate any suggestions/comments to help get my wheels to peak at 6500rpm as it should. Thanks. PS. This is an awesome site!

 

[J-GTi-R]

What happens after 4800rpm? How does it run? Does it stutter or die or what?

It could be a number of things, restricted fuel filter, the fuel pump not being good enough (have you changed this?), damaged fuel lines etc. but more info on how it runs would help solve the problem.

 

[Fast Guy]

Well, you've either got a fuel leak or it's running that rich at 4800 you can smell the exhaust. Fuel evapourates quite quickly, so unless you can see it leaking you'll have to look for staining. I'd be tempted too look around any fuel lines that might be disconnected, at the fuel filter for example or fuel rail/injectors. It could be a leaking injector o ring.
If you don't have a leak, then it could be something like an Air flow meter, lambda sensor or coolant sensor problem making you run rich. Exhaust leaks and blocked air filters can also make you run rich. It might be worth going on a rolling road for a set up, to check the fuelling side out.
Check your ignition timing too.