Q: Engine hesitates when warm - 1997 Toyota Tercel

asked by on

I have replace the fuel pump, fuel injectors, fuel filter, fuel regulator, tps, idle control valve, map sensor, ignition coil and cables, etc. That car has no catalytic converter and no engine codes. One thing I have notice is that when is cold runs better than when it warms up(when cold I can the rpm up to 3,500 as when warm will only go as high as 2,500 rpm, and when cold will run up to 60-70 min as when warm will only go up to 55-60mph.Another thing I have noticed is than when I clean the throttle area and intake manifold the problem seem to get better. I have check for vacuum leaks and nothing. I'm guessing either a gasket is bad when it warms up or I have a leak somewhere that I can't find. Any ideas will be greatly appreciated

My car has 190000 miles.
My car has a manual transmission.

Hi there. As you already know, replacing components without diagnoses can be expensive and time consuming without resolution. A few things come to mind concerning the lack of performance. First, camshaft timing needs to be checked. When the engine is at TDC (top dead center) #1 cylinder on compression stroke, the camshaft timing marks need to be lined up.

Second, with the engine at operating temperature, the ignition timing needs to be set at the manufacturer’s specification. Once timing is checked and set, put a vacuum gauge to a manifold vacuum source and then you should see 17-22 inHg. Even though there is no catalytic converter, the exhaust system may still be partially restricted by a faulty muffler or resonator.

I recommend having a certified mechanic, such as one from YourMechanic, come to your location to determine why the vehicle is hesitating and showing a lack of power.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Engine hesitates when warm - 1997 Toyota Tercel

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Is it bad that I put 10w40 in my engine that takes 5w30?

Your vehicle does not use 5W-30 oil. The recommended oil viscosity for your vehicle, according to Kia documentation, is 10W-40. If you drive the vehicle in exceptionally cold weather, well below 32 degrees, you can use 5W-30 oil but even...

Q: My code reader says I have a bad mass air flow sensor ans crank shat sensor test drive ran better shut off & engine Lt. Same code

Hi there. The problem you are describing, sounds like you may have a poor connection in the connector at the mass airflow sensor. Although, sometimes aftermarket parts do not perform as well as factory (OEM) parts. Check for corrosion and/or...

Q: Computer taken out by close lightning strike.

[The National Lightning Safety Institute]((https://weather.com/storms/tornado/news/what-happens-when-lightning-hits-car-20140625) reports that some vehicles struck by lightning experience external damage, including pitting and arcing, as well as internal damage to electronic systems and components. It is pretty likely that an electric pulse from the lightning...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...