Acceleration pump diaphragm ?

Hi, i am having problems with acceleration on my 1987 1500 over about 4000 rpm.The car idles ok and accelerates fine up to 4000 rpm then it starts to splutter and backfire then cut out

I have removed and cleaned the jets and tubes

I have read that you should see a swirt on fuel in the carb when the engine is off but i am only getting a dribble,could this mean i need a new pump diaphragm

Thanks Shaun

Hi Shaun,

Your accelerator pump diaphragm may well be perished or split judging by what you say about the poor flow from the jet. It should give a small neat little jet of fuel, not a dribble.

This device only serves to momentarily richen the mixture as you put your foot down, and is a "one shot" thing each time you press the pedal. It has no effect on running once the throttle has stopped opening.

If you are experiencing general poor running at full throttle you have a blocked main jet in the second barrel of the carb. This can be masked if you are madly pumping the throttle to keep it going, as the engine is running on the accelerator pump output. A thorough clean, new fuel lines and filter before the carb will fix blocked jets.

Cheers R

Thanks Rachael

I have new fuel lines and filter, so a good clean of the carb is my next job

Thanks again Shaun