Goof accelleration: Need codes!

I have a 1997 4door 5-speed 4.0L.

It is a great Jeep overall but I am having a problem when driving it. It tends to be "stubborn" and not want to accellerate. You can press the gas down from a green light and it will start to go then decide that it really doesn't want to. If i take it out of gear and give it some RPM's it will decide to go after put back in gear.

It only seems to happen from a stop. It never happens when I am cruising.

I do have a check engine light on with these codes:

Code 43 isn't listed in my 95 FSM - but 12 is recent battery disconnect (not a trouble code), and 55 is normal end of sequence. You'd do better on a 97 to get and OBDII reading if you can, because it will give more precise information. I think code 43 is a 96-up code for cylinder misfire. Note, however, that the system is not reading misfire directly here. It is taking readings from the crank position sensor and calculating speed fluctuations from that. In other words, it cannot pinpoint whether the misfire is electrical, fuel or mechanical in nature. Electrical problems in the injectors and harness should come up as a separate code, so I'd start by checking out the plugs and wires and go on from there.

Matthew's right. 12 means the battery's been disconnected within the last 50 starts; 43 means one of the cylinders is misfiring, but without the P-code, I can't tell which; 55 means, as Matthew pointed out, that there are no more codes being "thrown."

Thanks guys. So I guess plugs and wires would be the place to start, huh? What about a new rotor and cap?

Matt

mountainbiker said:

Thanks guys. So I guess plugs and wires would be the place to start, huh? What about a new rotor and cap?

Matt

Click to expand...

Rotor and cap won't hurt. Try to find the premium cap with brass buttons.

x2, the cheao caps with (aluminum?) terminals and such build up carbon really quickly.

After being totally lazy for months, I finally changed out the rotor, cap and wires this afternoon. Hopefully tomorrow I'll do the plugs.

I had some other projects.

But the Check Engine light is not on and the Jeep runs better.

Thanks guys!

Matt