Skip the auto shop - Our mechanics make house calls

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 1000 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

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 just my power steering belt that needs to be fixed, or is it a bigger issue?

When a drive belt breaks, it is necessary to determine the cause. It is not uncommon for a belt to wear out due to age, but sometimes the belt will fail due to another issue. You will need to inspect...

Q: When I start my car up its a rattleing sound was thinking catalytic

Hello, the catalytic convertor can make that type of noise. Inside the convertor is a honey comb shaped element that the exhaust gases pass through. Part of that element can fracture and become loose within the shell of the convertor,...

Q: Hi, I got my corolla 2012 engine overheated due to bad radiator, I replaced the radiator but the engine pick is not the same.

Hi There, Depending on how severe the engine overheating before was, this may have resulted in a blown head gasket or a head gasket that may have partially caused a cylinder leak. When this happens, this can cause the compression...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...