New to Jeepz

[KellenNold]

Perhaps this should have been my first post, but oh well.
Got a 89 cherokee laredo, 4X4, auto. Free to me, but has to last. Has a couple of problems that have noticed wafter reading all these posts.
1- plan on redoing ccv and pcv valves this weekend. Also going to open valve cover and clean (Has blowby that I have read about). Question - Do I need to replace gasket and do I use the liquid or the other (paperish?) gasket or both? Is carb cleaner okay to clean? Should I just remove all oil deposits or does something need to be left? I have read the other posts, but didn't see these questions addressed.

Also the car will die when the car is cold (don't know if limited to cold engine, but happens then) and when giving slight gas (creeping along <5mph). The engines just dies, like someone had turned the key. No coughing/sputtering. I figured I would start with fuel filter, as air, spark wires, sparks, are new. Just need input so I can narrow it down or narrow something out (poor college student). From reading posts, should I look at the CPS? Clean TPS? (prob should be done).

Thanks for the time,

Kellen

	Crank position sensor A crank sensor is a component used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on the engine.

	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).

[XJNick]

Hi, Just saw this post of yours...

plan on redoing ccv and pcv valves this weekend. Also going to open valve cover and clean

Cleaning the ccv and pcv hoses is a good idea. Though, i'm not sure you really need to remove the valve cover, it may not be that necessary.

Also the car will die <snip> and when giving slight gas (creeping along <5mph). The engines just dies, like someone had turned the key. No coughing/sputtering.

This is definately an Electrical issue. Meaning something in the electrical system is shutting down causing either the fuel pump, ignition, or both to stop. Don't do any work on the fuel system yet, as the culprit is most likely a computer sensor. The Crankshaft Position Sensor (CPS) is a good place to start. Also, the CAMshaft Position Sensor (CAM) could cause similar problems. Both of these sensors tell the ECU vital things such as when the engine hits Top Dead Center (TDC), what RPMs it's running at, etc..

The CPS is on the transmission bellhousing... not easy to get to. I doubt cleaning it will do anything as it is a hall effect (magnetically) activated sensor. The CAM sensor is inside the distributor. It is fairly easy to get to... but only mess with it after checking the other sensors.

Of course, there are other sensors (listed by importance) that could be causing you problems, mainly the Throttle Position Sensor (TPS), Manifold Absolute Pressure (MAP) sensor, and Idle air control motor (IAC). Which leads me to suggest you clean the throttle body and IAC motor passageways with carb cleaner to ensure the IAC and TPS, which are mounted to the TB, aren't sticking.

-Nick

	Crank position sensor A crank sensor is a component used in an internal combustion engine to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control ignition system timing and other engine parameters. Before electronic crank sensors were available, the distributor would have to be manually adjusted to a timing mark on the engine.

	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).