96 Jeep Cherokee Fuel Problem

[jmv3335]

I had the fuel pump go out, so i replaced it. Now it seems to run fine when it's cold, but when I shut it off and try to restart it, it doesn't want to restart unless I push the gas pedal to the floor while cranking, then it runs really rough and will die unless I keep the rpm's up around 2500-3000 for a few minutes, then it seems to run fine. I am also getting a code 22 for the engine coolant temperature sensor. I replaced the sensor, but still can't clear the code. I'm thinking it's some sensor that's messing up the fuel delivery, but haven't been able to track it down so far. Any help would be greatly appreciated.

[Bounty__Hunter]

Which temp sensor did you replace, front or rear of cylinder head?

Have you cleaned your throttle body? Sounds like it may be an IAC or TPS problem as well.

	Throttle position sensor A throttle position sensor (TPS) is a sensor used to monitor the position of the throttle in an internal combustion engine. The sensor is usually located on the butterfly spindle so that it can directly monitor the position of the butterfly throttle valve. The sensor is usually a potentiometer and therefore provides a variable resistance dependent upon the position of the butterfly valve (and hence throttle position). The sensor signal is used by the Engine Control Unit (ECU) as an input to its control system. The ignition timing and fuel injection timing (and potentially other parameters) are altered depending upon the position of the throttle, and also depending on the rate of change of that position. For example, in fuel injected engines, in order to avoid stalling, extra fuel may be injected if the throttle is opened rapidly (mimicking the accelerator pump of carburetor systems).

[jmv3335]

I replaced the one that feeds info to the computer, on the thermostat housing. And i've checked the resistance of the sensor throughout the range of temperatures, it's fine, and i've got 5 volts on the harness for the sensor, so I can't figure out why the damn light is still on. As soon as i restart it after clearing the codes, it pops right back on with a code 22

[jmv3335]

Here's an update, went and found out it was a loose connection where the harness connects to the CTS. Got the code to clear and she seems to start up and run fine now, but I don't think it's idling high enough at initial startup. It was about 40 degrees out this morning, and just a guess, don't have a tach, i'd say it was only up around 1500 rpm's for less then a minunte then back down to normal idle. It also felt like it was missing during idle, and then some when i reved it up. I'm gonna check the spark plugs and see if the incorrect sensor reading was flooding the engine and maybe fowled them out.