Outer Limits 4x4 Board

what could this be my feroza is a f300 model and has had the injectors and filter done and every time you take from each gear it has a dead spot

geeze i have a stut stut stuter problem

Maybe cause its a 1.6l petrol?

Are you running bigger tyres at all?

Sounds more like a flat spot on the air/fuel supply. As it has injectors it should make it easier to trouble shoot this problem, I would check the throttle cable, it goes from your accelerator pedal to the throttle body, you adjust the tension of it at the throttle body end...

If this is not correctly set for the injectors, it will either be supplying too much fuel or to much air, the cable governs the position of the butterfly valve which controls the amount of air that is allowed to flow in. You notice this problem at lower rpm's. You should be able to replicate the problem in your garage, pop the hood, start the car and very very slowly with your hand twist the valve open. You should here a point that it will start to run rougher or noisier.. If you take it around the block first and pay attention to the rpm's where the flat spot occurs that will signal where to expect the problem... Same problem will occur in neutral as it isnt a load dependant problem.

As for the correct tensioning and setting of this cable if it is the problem, the service manual will tell you the correct specs for that vehicle.

It may not be the problem but that is what it sounds like.

Those symptoms sound exactly like mine when the oxy sensor was dying. They respond slower when they're on their last legs, so you get a hesitation after every gear change. Might be worth looking into - search the FAQ's

Doc_Acos wrote:Sounds more like a flat spot on the air/fuel supply. As it has injectors it should make it easier to trouble shoot this problem, I would check the throttle cable, it goes from your accelerator pedal to the throttle body, you adjust the tension of it at the throttle body end...

If this is not correctly set for the injectors, it will either be supplying too much fuel or to much air, the cable governs the position of the butterfly valve which controls the amount of air that is allowed to flow in. You notice this problem at lower rpm's. You should be able to replicate the problem in your garage, pop the hood, start the car and very very slowly with your hand twist the valve open. You should here a point that it will start to run rougher or noisier.. If you take it around the block first and pay attention to the rpm's where the flat spot occurs that will signal where to expect the problem... Same problem will occur in neutral as it isnt a load dependant problem.

As for the correct tensioning and setting of this cable if it is the problem, the service manual will tell you the correct specs for that vehicle.

It may not be the problem but that is what it sounds like.

The throtte position has very little to directly do with the injection system.
The only direct connection is the TP switches and they only work at idle and near full throttle.

What actually does the work is the MAP sensor which responds to changes
in the manifold pressure - which is of course a function of the throttle blade opening - but not solely or directly.

Miss adjusting the throttle cable can cause a problem by holding the throttle blade open, causing the TP switches to read incorrectly but it doesn't affect the WAY the EFI system works as suggested.

The TPS switches however are nothing but trouble with the idle one
failing regularly, this can cause funny things to happen at idle, so would
also be worth checking....

thanks guys ill check it this week end