engine troubles above 2500rpm

[aldea6]

Hello,I have a S1, 2.8i Ford engine, fitted with the Bosch K-jetronic injection.The engine starts easely, idles regularly, and the car runs smoothly until it reaches 2500/3000 rpm ( whatever the gear ); then the engines runs very roughly,doesn't accelerate anymore, and shakes very badly,so I have to go down to lower rpm.This happens only when the engine is "in charge",with the car running.If I press the clutch pedal or stop the car and put the gear in neutral, then the engine revs normally to 5500 rpm.
I suspect a fuel injection problem, but I don't know if the K-jetronic is easely tunable for an amateur.It seems than the electric fuel pump is quite noisy ( I could hear it when driving).
If anyone has an explanation......
thank you and many happy corners

[AquaRegia]

Hi first I would run an injector cleaner through the engine add it to a full tank of fuel. If the fuel pumps going best to replace. You need to check fuel pressure, that will give you an idea if the pumps on its way out.

[malcolmr]

i have had the same problem, have replaced plugs, rotar, dis cap,fuel pump, fuel filter, coil, leads, battery, the next step is the fuel dizzy, if the car sits without use for a while these can be tempermental. also when i bought my car back in 2000 both the fuel pipe and injector fuel pipes had been lagged in heat resistant lagging suggesting exhuast manifold heat could be creating fuel starvation, when i run the car in cool conditions it really responds, on really hot days it becomes lumpy and can cut out, high temperature plus hot manifold i dont know, any advice would be appreciated

[GreenV8S]

Missing at high revs and wide throttle suggests a weak spark to me, I'd look to the coil, ignition amp, HT leads etc. A passive strobe (aka HT tester) can be handy to track this sort of thing down.

[aldea6]

Hello, thanks for your answers.I've removed the fuel pump,accumulator and fuel filter;all these were contaminated by rust coming from the fuel tank.I did my best to clean the fuel circuit and the engine is running satisfactory now, except that the spark plugs are quite white, meaning a lean mixture, although the water temperature remains steady at 90°.I'm going to clean the injectors and installing a high-flow filter between the tank ant the pump.I hope this will fix the problem.
I find the "S" a very fine car to drive...when the engine is tuned.