01 cherokee speedometer & tacometer drop to zero
 

I have an 01 cherokee sport and ive been having this problem where the speedometer and tacometer drop to zero while im driving, and sometimes the odometer will read "no bus" instead of the mileage. sometimes the two guages will drop for a second and sometimes they will drop for a few minutes. sometimes they drop together, and sometimes separately.

another problem that i think is related is if i start the car while the engine is hot it occasionally will run rough until i put it in gear and give it some gas, then it clears up and runs fine. when this happens it sounds like the fuel isnt reaching the engine and it is going to putter out. infact it has puttered out twice on me over the last year and a half.

This has been an on going problem that only happens in hot and humid weather. I live in CT and during the winter i never have this problem, but as soon as summer rolls around hotter temps and more humidity the problem shows up again.

my thought is that there is a bad ground that acts up when its hot, but i dont know.

has anyone had this problem or have any idea what it could be?

Theres a good chance that your crank position sensor is starting to shut down. It can cause a long list of strange issues depending on how its working. I picked up my 99 for $450 because they couldnt get it to start because of this. My buddy has a 94 and his was causing the same issues you describe.

I have a 2000 Classic and I have the same issue. But don't worry it is an easy fix. The no bus is the key on this one.. It means you have no power to your gauges. In our case it is a loose wiring harness under the dash. I usually just lay with my head by the peddles and look up towards the radio and there you will see a big wiring harness. Grab both sides and make sure it is pushed together. However it has been posted that the crank censer can cause this but I had gone that route and it was the harness. I am not an expert but this is what has worked for me..

As for the puttering when it is hot I have seen that too but I have not fixed that one..
Good luck and happy trails

http://ritasfitnessfirst.com/images/taco.jpg
http://www.hydro-temp.com/images/meter.jpg

sometimes my speedo wigs out, and I think its the ground on the sensor or the internals of the gauge itself, but mine is a 91 and I dont know if they correspond

you could check the fuse going to the gauges

This is mostly likely your issue! I had the same thing with my '99.

I checked all the wire harnesses i could see and the problem is still there. So i guess i'll check the cps next.
And I think i have fixed my hot start problem. What i did was wrap the fuel injectors with an adhesive heat shield that i got from summit racing. I did this about 2 weeks ago and so far haven't had a problem. So if anyone else has this problem try what i did.

which issues? the rough start or the no bus and guages dying?

Gauges on my 99 did the same and as was stated was the connector. As far as it idling rough or hard start could be the cps or bad O2 sensors.

Before you go the CPS route
 

...Search the forums on instrument cluster harness connection. The giant harness connector is a documented problem issue- it just goes bad.

Heres a test: next time ity happens and your gauges go dead, push in the trip meter/odometer button. If your gauges come back, my guess is its definitely the connection, not the CPS.

There was a post on this a while back. You can buy a replacement for somethng like $16 and re-wire your harness to it, or you could pull it apart (like I did) and blow air into all the connectors, clean any terminal ends you can see, etc. It for the most part fixed my issue.

The CPS is thrown out on this forum a lot as the "catch all" culprit for any number of issues, and they all may be actual symptoms of a failing CPS, but my understanding is that if the CPS is bad your car won't run, PERIOD. Please correct me if I am wrong- but my dad (a longtime car-engine tinkerer and rebuilder) told me that there is no middle ground with a failed Crank Position Sensor.

The rough running can come from a bad number 6 injector...the one in the back...when it gets hot it will either stop sending fuel or missend, i noticed it on hot startups never had an issue when it was cool and if if i cool the injector off it runs fine. I made my own heat shield for it and it hasn't happened since... little bit of tin foil. Eventually it needs to be replaced but i want to replace with a whole new set from a 94 5.0 and that gets costly! Good luck!

2001 Can bus drop out
 

I have the exact same problem with the addition of the airbag light coming on. If you figured out the solution please post.