97 Jeep Grand Cherokee Laredo kills while driving

At first it wasn't reading any fault codes except for when the battery was disconnected. But day before yesterday it started reading code 43 and I know in the Haynes it stands for "multiple cylinder mis-fires". I've had been paying close attention to when my Jeep goes to kill while I am driving and it seems that when I hit speeds between 30 and 40 mph that is when it kills or tries to kill. But long as I am parked/stopped it doesn't. It is so odd, I have never had a truck do this to me before.

Grace

Just out of curiosity, how much gas was in the tank whenever this happened? 1/4 tank or less, maybe?

The '97 4.0L ZJs had a TSB to replace faulty fuel pumps that would falter or momentarily stop pumping at a 1/4 tank or lower, when accelerating or when making sharp left turns. Sometimes the engine would just die in traffic, causing a few accidents, or the engine would go dry for a few seconds and kick back in (just before you got rear-ended). I've had two '97s, and both suffered the problem. Dealer changed the pump 2x on the first one - the first tme they used another defective pump assembly - I'm about to take in the second one for the same repair.

HTH,

Doug Gavilanes Garden Grove, CA.

msgrace wrote:

I just replaced my fuel pump. I've had it do that when turning left with a 1/4 tank. I've also had it not start right up, stall out after starting and taking a long time to start. If you can handle it, a new pump for a '97 TJ is $99 at Pep Boys, $220 at Papa and $420 at the $tealership.

I can have a full tank of gas or 1/2 tank of gas and it will do this to me. I just put the new fuel pump and fuel filter in Dec. 8th. I am wondering if my crankshaft position sensor went out again because the first few days after I put a new one in it ran fine, then all of a sudden it is acting up again.

Grace

Check the connector, It sounds like it could be dirty (corroded) or even a little loose. If its dirty spray it with some contact cleaner, wd-40 will work in a pinch but it should be cleaned again later if you use wd-40.

Snow...

I have a new crankshaft position sensor on order from the Jeep dealer ship because the truck is now with the check engine light on and coding 11 for no crank reference signal detected during engine cranking; intermittent loss of either camshaft or crankshaft position sensor. The senor was on order before it started with the check engine light coming on. Since the light is on I can't even get the truck to stay running. As you as you crank it, it dies and if it does stay running, it is running very very rough with the rpm varing from 0 rpm to 2500 rpm without even pressing on the gas. I will let every one know as soon as I get the new CPS on if it is running alot better.

Grace

I would recommend you just clean the plugs and sockets for both the crank and cam sensors with a spray contact cleaner. Even WD40 will work to see if it is just a bad connection.

Mike

Since you can't really make it any worse, try finding the connector for the CPS, hard up by the firewall. Unplug it, look inside the connectors to see if you see anything but shiny metal, plug it back in again and see if it runs.

msgrace wrote:

Got my new cps installed yesterday and as of now no more problems with my Jeep, even my gas milleage has improved. I hope this is the last time I have to replace anything on it for awhile. Thanks to everyone for their help.

Grace