QuestionQUESTION: Did hook the multimeter,turned to 20k, 1st reading 7.58, after moderate warm up, temp needle just started to move of the Cold.
2nd reading (gradually and steadily)went done to 2.74, then shut off the engine. Apparently this sensor is good. What's next?
Can we speak on the phone? Could make this go faster.
ANSWER: Hi Bob,
That reading of 2.74k ohms seems high if the engine was warmed up to operating temperature. I have another possibility. I assume that the sensor is mounted on the side of a box-like housing which contains the thermostat and that the hose that comes out of the front of the box goes to the upper radiator, correct? If so, then is there a threaded plug on the top of the box into which an 8mm allen head wrench fits? If all that is so, then one possiblity is that you have air trapped in the thermostat/housing box. That will happen when/if the coolant level drops below the level of the box (due to draining the system or a loss of coolant) but then when the system is refilled that threaded plug was not removed so as to allow the coolant to rise back into the box without trapping air within it.
So if this is all true, what you would do is drain off a quart or two of coolant from the radiator drain plug, then close that plug. Then use an allen wrench to remove the plug on the top of the box, then refill the system via the radiator cap until the coolant rises into the box and fills it to the top where it meets th plug's opening level, then lub the threads of the plug with oil, insert the plug and tighten, then refill the system up to the neck of the radiator cap. By doing that precisely you will than have the box totally filled with fluid and so the coolant temp sensor will be in actual contact with the coolant instead of surrounded by trapped air. This detailed instruction is unique for the 2.2/2.5L 4cyl engines.
This may explain your problem as well as the higher than expected reading on the ohmmmeter. If that doesn't solve the problem, and the resistance when the engine is warmed up fully is not down to around 1,000 ohms, then I would replace the sensor.
Roland
PS About phone calls, I prefer to use the internet for reasons of privacy and avoiding the involvement of other family members in extra phone calls.
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QUESTION: No problem w/ the privacy, just getting impatient. At full operating temp, the reading was .67.
I did take the truck for a spin. the Check Engine light is back on. It ran ok, except for no power on acceleration, but it didn't buck or hesitate.
I didn't find the threaded plug. I did replace the coolant in the spring. Ran the truck for 20 min, turned on the heat and filled to appropriate levels. Didn't replace thermostat. After that ran fine until this problem. This truck has 123k on it and has run great. Never really had any climbing power, lately got progressively worse.
Seems to have more exhaust than it should and when I replaced the bank 1 O2 sensor & that didn't work I took it back, it had alot of black soot on it and the autoparts store guy said it was running rich. He does have about 25yrs in the parts business.
What do you have up your sleeve now?
ANSWER: Hi Bob,
That 670 ohms is about right. With the check engine light being 'on' there should be a fault code stored in the engine controller. Try the on-off-on-off-on and leave on with the ignition key, in 5 seconds or less elapsed time, then count the flashes of the check engine light. If it doesn't flash then ask the autoparts store fellow to plug in a code reader. The socket is either under the dash, or in the engine compartment by the driver side strut tower. I am not certain which location because '95 was the inception of the OBD-II code system, but I don't believe the truck lines got into that system until '96. A fault code is the key to solving this problem.
Roland
PS: I have another idea, because you believe that the engine is running rich. The fuel is injected by a single injecor located in the throttle body. You can easily observe how it is functioning by removing the lid of the air cleaner housing. While the engine is idling vies the spray pattern of the fuel that comes out of the injector and lands on the throttle butterfly plate. It should be a very fine symmetric spray with no droplets of fuel. Then have a helper turn off the engine and observe for any after-drip from the injector. Either after-drip or asymmetric spray, or frank droplets in the idle spray are indicative of a failed injector and thus a too rich mixture. If you get a code, a 26 or 27 or 52 would point also toward the injector.
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Throttle Body
QUESTION: The code was 18 (flashes), I did it 3x. I check the throttle body and no spray came out on top of the butterfly plate. Keep in mind I thoroughly cleaned the throttle body and now I noticed the black ring around the butterfly plate. It idles pretty good, could be raised a little. Where is the idle screw?
Reminder; 96 Dodge Dakota 2.5L 2wd 4cyl manual 5 speed 123K miles, regular cab.
Here are pics of the engine. What are the 3 pieces connected to the throttle body?
AnswerHi Bob,
Do the flash count again. Notice that there are pauses mixed in with the flashing. Count the number of flashes before each pause. Then repeat the process. The last set of flashes are always 5 in each, which means 'end of code readout' so the question is how were the first 8 flashes divided up by pauses?
Remember at the start of your questioning I said I don't have a manual for the trucks. If there is no spraying on the throttle plate, then this engine must have multipoint fuel injection (one injector per each cylinder). I can't identify in the photo what you are asking about. If one of the four injectors is bad then we should get a code for that. I do have code listings, so let me know the counts.
Roland
