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Why is it when driving the RPM gauge drops or jumps up?

When I'm accelerating and get to required speed my RPM gauge either drops and steadies or jumps up then steadies back. Also if i push her too much to go faster too quickly it starts acting like the transmission is slipping. I've figured out that if i stop (in a safe place, of course) and cut the engine and wait a few minutes and restart the engine the transmission is fine again. I was told i needed new intake gaskets, i did that and it's still happening? could it be a sensor?

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Is it just your tachometer or can you feel the vehicle surging? Any errors codes or is your check engine light on?

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I agree with oldturkey - the first step is to check the computer memory for trouble codes. From your description, you might have a crankshaft position sensor or camshaft position sensor that is starting to fail.

BILL

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My service engine soon light is on and the code it's throwing is multiple misfire, but that is a whole different issue. I know what that is from. It wasn't throwing any codes when this started happening but i was told i needed my intake gaskets replaced. But after having that done it didn't fix the problem. It is just the tachometer jumping unless i come to a stop then the car sometime, not always tries to lunge forward.

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Okay, thank you Bill for your insight. I will have my mechanic check the sensors you mentioned yesterday. As for the multiple misfire code, i need to replace 2 of my coil packs and get new plugs and wires before i'll know the extent of the over-haul i'll need to do. But i do appreciate all your help and wisdom.

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Need help i have an 2005 toyota sienna and when i start it it goes straight to the number 1 it use to idle in 0 area and now when i drive it and com to the stop light and to move off it jumpor i have to rev it to move can anyone help me please i have change transmission fluid and filter this pass week already.

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A multiple misfire can certainly cause the engine to surge. You said you know what this was from - please elaborate.

The tachometer is just showing what the engine is already doing; it does not affect how the engine runs.

I still say there is something else going on in your computer system. Checking trouble codes is only one thing to check. Most scan tools can also check sensor values while the engine is running, and if you know what the sensor should be reading, a bad one can be spotted easily.

BILL

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Hey friends if your car RPM goes down to zero then do following steps.

1.Check your fuel pump

2.Make it Throttle body clean

3.Make your injector clean

4.Check your RPM Sensor

5.Check your car Emulator

6.Check if there is any gas leakage near by your car engine.

Do All the above your car will be smooth and there will be no problem related to RPM.

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Why is the rpm staying on 0 on 99 Camry when sitting still or driving

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This could possibly be your output speed sensor, related to the transmission. It controls the odometer. Generally this part is inexpensive, and you could locate it, and possibly change it yourself. Hope this helps!

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Alternator may not be charging Battery properly

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Engine have fuel problem . Somewhere the fuel drop then suddenly rpm decrease better check the complete fuel system from tank to injectors also check the rpm sensor .

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check fuel pressure between fuel pump and injectors. you may have a fuel pump that is about to fail.

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I have a 1992 Chevrolet blazer I went in to get fuel filter changed they broke the fuel line said I needed a new fuel pump they fixed it but I got a oil change 2 months ago and a tune up new spark plugs disturber cap, spark plug wires, I had a leak in the pcb vulvae they put a new tube but its still hesitating and cutting off rpm keep idling and going down check gauges and service engine soon light on and battery light when i turn the key over all auto part stores say they dont have the diagnostic for a 1992 i just want to hear my pipes and not keep cutting off 2000 dollars and my blue boy stll sick please help!!!!!!!!!!!!!!!!!!! I'm a lady if any one can help my name is MissDronda Bivens on FB the profile with the glasses

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