Engine speed increases with no increase to vehicle speed

hey see other notes I sent

Is the car equipped with the Automatic Transmission?
If so, read on.
Otherwise skip to the end and answer some questions.

POSSIBLE SCENARIO:
I have observed a condition where my car surges slightly when the torque-converter clutch (TCC) cycles between lock and unlock when driving on an uphill grade.
First some basics and history that will explain why the TCC is used.

Engine, Torque Converter, TCC, and Transmission relationship--
The TCC allows for a solid connection between the engine and transmission which allows the input to the transmission to rotate at the same speed as the engine.
Without a TCC, there is slippage between the engine and automatic transmission. The slippage is greatest at low engine RPM. That is what allows the engine to run with the automatic transmission in gear, like when you first shift into gear or stop at a stop sign. When the throttle pedal is depressed, the engine RPM begins to increase and the torque converter begins to slip less and less the more the engine RPM increases. The car moves. But even at cruising speeds the torque converter slips slightly. Engine RPM is greater than transmission input RPM, which is realized as slight decrease in fuel efficiency.
When acceleration is complete and a constant speed is being maintained, the engine power output is reduced to the point where the TCC can engage and eliminate any slippage between the engine and transmission. If the car has a tachometer the engagement of the TCC can be verified when a slight reduction in engine RPM observed without a corresponding change in vehicle speed.
One method used to test the operation of the TCC is as follows:
Find a flat section of road where it is safe to perform the test.
Reach a steady speed and keep the gas pedal depressed with one foot. While observing the tachometer (or listening for an increase in engine RPM), with the other foot depress the brake pedal enough to activate the break light switch but not enough to engage the brakes. When the brake light switch activates, the TCC receives a signal to disengage. With the gas pedal being held steady, release the brake pedal and the engine RPM should decrease when the TCC engages.
Old cars with Automatic Transmissions did not use a TCC. I believe the TCC was put in use in an attempt to increase fuel economy.

MY EXPERIENCE WITH SIMILAR SYMPTOMS
The condition that causes that issue on my car is this:
- A slight uphill grade increases the load on the engine.
The car tends to gradually slow and it is necessary to depress the gas pedal to maintain speed.
- Depressing the throttle pedal (manually, or automatically with cruise control engaged) signals the torque converter clutch to unlock when the load increases slightly. (A more drastic load increase would signal the Transmission to downshift to a lower gear.) The corresponding increase in engine RPM and output is enough to compensate for the reduction in speed. When the vehicle speed, engine RPM, and throttle position stabilize to the point that the TCC will engage and the engine RPM will reduce in correspondence with TCC engagement. Now, if the road conditions have not changed, power output is not enough to maintain vehicle speed. With the increased load caused by full engagement between engine and transmission, and the cycle (surging) repeats itself until the road conditions change.

Does that help?
If not:

QUESTIONS
Please define the symptoms.
What are the road conditions when the surge occurs? (A slight uphill grade?)
What is the frequency of the surge?
Does the engine power output have a noticeable surge?
Is there a speed change related to the surge?
Does the tachometer move up and down with little or no change in vehicle speed?
Are all instrument indication in the normal range?
What else has changed?

Good luck!

Hi, Without knowing vehicle name or year I must state this is for petrol models, your coil needs renewing, Derv you have air coming into the fuel system. Please leave me feedback, Malcolm Campbell.

Can you tell if the engine speed increased ?
Something in the transmission could be slipping, or the tach could be faulty.

These engines are known for ticking fan clutches. If the ticking doesnt significantly increase with the engine revving, it may be the fan clutch. The clicking usually happens momentarily and dissipates, and increases only to a certain engine speed. If its an internal mechanical issue, ticking will increase simultaneously with the engine speed increase.

PROMLEM MAY BE BECAUSE LOW IDLE SPEED ADJUSTMENT. INCREASE THE LOW SPEED/ IDLE SPEED BY INCREASING THE FUEL INTAKE . IN CARBURATOR VEH. ADJUST THE IDLE SCREW CLOCKWISE. IF IT IS FUEL INJECTOR INCREASE THE FUEL AT PUMP ITSELF.

Clutch seems to be slipping, replace.

Thank you for getting back to me. I would like you to check your transmission fluid. start the engine and let it warm up at idle speed for about 15 min and check the fluid. It sounds like you do not have enough in it, there for the whining noise with increase of speed since your transmission is speeding up with the rate of your vehicle. If this does not help and the problem persist please let me know. If the noise you were hearing was coming from the u joints of the vehicle it would not make a whining noise with increase of speed. The u joints will only make a noise when they are going bad when the vehicle is shifted into any gear from the shifter( EX: park to drive, park to reverse ECT.)

if the sound increases with vehicle speed, it is a drive issue, like wheel bearings or front wheel drive gears. if it increases with engine rpm, it could be a bad engine bearing, alternator or water pump.

I would have the car checked on the computor.Even if the engine light is off it will store the codes.When you get the codes it should point you in the right direction.I would say it's posibly the throttle position sensor.