QuestionHello again Roland,
First, I want to thank you for helping me with my flickering dash lights a while back. The problem was a corroded ground just as you mentioned.
Another problem has crept up I am hoping you can help me with. When driving my vehicle first thing in the morning or after it has been sitting for a long period of time, it stumbles when accelerating for about the first half mile. After that it runs fine. The plugs and plug wires are good and I recently cleaned the throttle body and IAC valve so I know there is not a problem there. There are no codes in the computer. The vehicle has approximately 65,0000 miles. Any ideas? Thank you for your continued help.
AnswerHi Rennie,
Because it is temperature-dependent, apparently, which suggests an improper fuel/air mixture, I would check to see how the coolant temp sensor is reading when cold (it should be around 7-13,000 ohms) and then drop down to around 700-1000 ohms when at operating temperature. It is located on the lower intake manifold near the thermostat housing.
The inlet air temp sensor which is on the left side of the engine where the inlet air corrugated tube connects to the throttle body is another possibility for temperature inaccuracy (it is near the throttle position sensor and toward the midline from the oil filler cap; it should show the same resistance variation as the coolant but of course it won' drop so low when the engine warms up).
The ambient air temp sensor also inputs its reading to the engine control module so if you have an environmental temp reading on your overhead console check to make sure it is accurate. That sensor is located at the middle of the front edge of the crossmember underneath the radiator
Another way to assess all these sensor is by a diagnostic readout box which gives you the readings "live", and may be the only way to identify what is the cause of the miss when cool.
That is my hunch as to why you have this problem.
Roland
