Skip the auto shop - Our mechanics make house calls

Q: My truck surges at low and idol speeds. Cold or hot. Sometimes quits when put in gear. Very low speed has a miss.

asked by on

I have replaced most sensors and ignition components . Check engine light is not on. If I unplug temp sending unit , service engine light comes on and vehicle stops surging . I've rebuilt throttle body and replaced both injectors . I've changed tps, iac, map, egr , plugs, wires distributer . Also checked for vacuum leaks everywhere that I know to check .

My car has 180000 miles.
My car has an automatic transmission.

A: Hello and thank you for contacting YouMecha...

Hello and thank you for contacting YouMechanic. When you unplug the temperature sending unit the problem goes away but the engine light comes on. Check the plug to the sending unit for any corrosion or debris. Look at the pins to the temperature sending unit and make sure that they are not bent or broken. If the sending unit and harness looks fine then you would need to replace the unit.

I recommend replacing the temperature sending unit and then running the engine. If you need help with diagnosing your Check Engine Light and rough running symptoms, then contact a professional, such as one from YourMechanic. One of our mobile technicians can come to your home to assist you with the necessary repairs.

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: Fuel or ignition problem.

If your complaint is a crank no start, it is likely that you have ignition problems. It could also be the fuel injection relay. The most likely cause for your no start is an ignition module in the distributor assembly....

Q: Engine running rough and light now on.

Yes you could have bad fuel in the system if that is the case. However, you may want to check and make sure your fuel filter is good, and make sure there are no extra leaks in the the air...

Q: Van stalls when it gets warm, i wait a little while 15min to 20min it starts up, until it gets to warm and stalls again.

Check the ignition coil on your engine. If the coil in new with the distributor, then the problem could be the computer or module of the vehicle. An ECM or PCM will cause the ignition system to shut down if...

Related articles

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...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.