Engines die in cold operations

[baracuda1974]

Hello folks:
Here is my problem(s). For the past month I have been having problems with my 6 Inline 98 ZJ. If I start the O’ Grand and drive off, it would start to loose power or stalls, even if I have the gas pedal to the floor. Is like the engine can not burn the gas quickly and in some occasions I get a backfire blast form the engine compartment. Now, here is the kicker, if I let it warm up to 210 degrees F these problems goes away and it dose not appear until the engines cools off (Next morning going off to work). I have changed the sparkplugs and wirers, have cleaned the throttle body, changed the distributor cap and rotor and gave it a good tune up sort to speak. This helped for 3 days, but, the problem came back.
What sensor could it be? Or do I need a new coil? And, if it’s the sensor, where are they located and what are there names? If I am not mistaken there are 3 sensors in the throttle body alone, what are these sensors called and what do they do?
Thank you for your support on this matter.

Mark Cin

PS
I did installed a cold air intake system to the O’ Grand but it has been over 5 month ago that it was installed.


OK, I saw in this forum this problem that sound lioke mine.
Problem #6 crankshaft sensor
symptoms:
When you are driving it will suddenly lose power like it is not getting fuel when you press the gas pedal. It will spit and sputter a bit and then run again. Sometimes it works fine and other times it runs horrible, or car will not start sometimes.

If you're replacing one and there isn't a piece of paper on end of replacement then no adjustment or gap needed. If there is a piece of paper on the end, don't remove it unless directions tell you to. It will come off when you start jeep.
well, I took the bull by the tail and faced the situation, but first I had to be smarter than the CPS,
I tied a long string to the disconnected cannon plug , in the engine compartment ,used a long extension , with a universal swivel attachment for the socket on a ratchet , removed the CPS bolt, tied another string on the old CPS end along with the new cannon plug
and pulled it thru over the bell housing into the engine compartment , otherwise it would have been very difficult to install any other way ...and glad thats over.

Now, what is a CPS and where is ti located in the engine comparment? To top it all, how do I fix this?

[Bob D.]

CPS = Crankshaft position sensor. On 1999 - 2004 it's on the passenger side, not sure about a '98, may be in the distributor that year.
Get a DRB code reader and see if any fault codes are present.
Many owners of early model Grands here, one of them should know the location.

[baracuda1974]

will do

[Triksr4kds]

The crankshaft position sensor for your jeep is on the drivers side of the transmission bell housing. Trust me, it's going to be a pain to get to...

[baracuda1974]

Git it. But, the main quetion has not been answered, can the CPS be the prblem I havein my O' Grand? or is there more to it?

[Triksr4kds]

In most cases you will get a code when a sensor fails. It is possible for the computer to not throw a code if the problem is not very significant to it. Have you been able to pull any codes yet? It probably wouldn't hurt to change out the CPS, but without the codes, you'll just be throwing parts at it. Search around on this forum for "Grand Cherokee stall", you'll see that this is a common issue and you'll see everyone else's resolve. I had that problem too, and it eventually got worse and worse. I threw parts at my engine for a year before I fixed it, and it was the Idle Air temp sensor that is on the intake manifold... Everyone's opinion is going to differ, but I would say the CPS is a good place to start.

[baracuda1974]

Ok I have installed a new Air Temp Sensor, change the spark plugs and new set of wirers, and cleaned out the cold air filter. The problems are still there. So I got the handheld code reader. It gave a 351 code that is a “Ignition Coil A Primary \ Secondary Circuit Malfunction. Well in my small ability to fix things I got a new ignition coil and installed it thinking that was the problem. The very next day I hooked up the reader and sure enough the dreaded 351 came back up. Mind you that the check engine light never came on and still doesn’t come on with a malfunction. Now the main question is, what the hell is a Ignition Coil Primary \ Secondary Circuit Malfunction. I know what is a circuit and an malfunction but is it a sensor or a relay not working or is it something more that it is out of my hands and have to take in to the shop to get it fixed.
Please someone let me know I am going crazy with this problem and the misses is getting PO because I can get to the root of the problem.
Yours truly,
Mark Cin

PS
When it stalls you can smell gas fumes coming from the engine compartment. It is like the engine is not getting the right spark to burn off the gas. Can this be the CPS (crank positioning sensor?)

[baracuda1974]

Still waiting for an answer from up above. Any one has any idea on this 351 code isue. Let me know.
Thank you for reading this post.