My cal pump t7500 only buzzes when i plug it in. If i shake it around i can get it to pump. Do I need a new pump

yes it can if you have someone put there ear by the gas tank and turn the key to the on position but dont start . the fuel pump should make a buzz noise if it dont then it is more then likly bad

Run tests. Fuel pressure correct? Spark at plugs when cranking? Fuel injector pulse working? Compression test?

Poor performance from spark plugs and wires. mine did the same thing. I tried to change the spark plugs, and found oil within and around the spark plug boots, which is problematic, but not the actual cause of your problem. If you find this, your valve cover gasket needs replacing.

If not, just get new plugs and wires. Got that done and shaking almost disappeared completely.

mb

BAD SPARK PLUGS AND WIRES DIRTY FUEL INJECTORS AND STOPPED UP FUEL FILTER OR WEAK FUEL PUMP WILL CAUSE ENGINE TO SURGE.

I had the exact same issue. I left mine out for the winter and when I plug it in, the breaker trips. My warranty was up so my friend took it apart. The seal had broken alowing water to leak into the bottom the pump where the wires connect to top of motor. This is supposed to be water free and is protected by several seals.

I am currenlty trying to put sealant where the cord goes into unit to stop water from going in. I will let you know how that works.

One tip my friend recommeded is to make sure there is no stress on the cord as it appears this seal is weak and and kind of stress will break it. hope this helps -- Rob

In the back of the motor you will find a start capacator. This will be a brown or black cilinder 1" around x 2" long. With the power off unhook the wires to it and note where they go, their will be two or three. You will need to go to a motor shop or a good pool store to get a new one. Then just plug it in and you should be good. If this dosen't help than you may have problems in the windings of the motor and will need to replace it.
The start cap supplys a boost of power to get the motor turning. Once it starts then the cintrifical switch kicks out and opens the points in the back of the motor. When it goes bad then the motor just hums and won't start turning. Be sure to replace with the same cap. The numbers you need will be printed on the side of the cap. Good luck.

throttle sensor fault. might be cleanable if removed. also could be a damaged idle valve, might be staying open this cal also give high revs. and tap and it will go down as its sticking. acceleration is the throttle sensor i may have blank spots. removing it and spraying in the switch breather hole and shake the cleaner around and turning it at the same time should clean the sensor. then shake and leave to drain out the cleaner. idle valve you will need to remove it and clean ti with some carb cleaner and a brush like toothbrush, clean it thorley out push the pin in and out to make sure its not sticking at same time spray it. then when clean leave to dry. then refit them. hope this helps

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Probably...You can try to check for any debris that got into the impeller and has the pump seized up causing it to buzz loudly instead of run. If you do not find debris but turning the impeller by hand “snaps the impeller free” so-to speak you will need to start looking for a new pump soon. You may get it running but water has likely penetrated the sealed motor section of the pump and ‘froze’ it. Moving it free by hand will be a temporary fix.

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John

It sounds like you have a bad connection..either in your wall socket, or the electrical cord on your cal. is getting old or shorted where it connects to your cal. If it is not these connections, your may have dropped a staple or paper clip in your cal. turn cal off and shake machine to dislodge it. turn cal back on see what happens. if it starts to smoke, etc. etc, this was your problem and you need a Monroe cal. good luck

have you try cleaning also the air filters..? fuel pump..?