okay first off let me say thanks to anyone who can help. also i know there is a search bar but i couldn't find one exactly what i needed. so my jeep has the inline 6 and 117,000 miles on it. For some reason it hardly EVER stars on the first turn. But also it seems to spit and sputter and loose power around 10 minutes after driving it. sometimes it will buck but its odd and very annoying. Ive already replaced the MAP sensor, plugs, wires, fuel filter, Fuel pressure regulater, and the ignition coil, crank shaft position, distributor cap. im running out of ideas so any help would be much appreciated. Thanks in advance
I'm betting the O2 sensor. You may have replaced everything *but* the one part that actually needed it. Have you checked for error codes?
The big clue is that it only does it after running for a while -- the computer does not read the O2 sensor until its up to 185 degrees at the thermostat. If it starts reading the O2 sensor at this temperature, and gets a weird reading, it goes into a default mode.
***--- Wrecking Crew member ---***
"I've prolly been around longer than you think"
one thing my jeep did was a distributor wire was sometimes contacting some other wire/metal pieces and shorting. but it would only occur while driving and if a bump hit it the right way and such, causing it to buck and jerk. it may be something as simple as that
You were about right with the O2 sensor. Check your manifold for loose/missing bolts, especially on the rear of the exhaust manifold near the firewall. Check the exhaust manifold for cracks, especially around the collector tubes.
Had this issue with my sons jeep, thought is was a fuel issue, replaced the fuel filter, fuel pump assembly, still did the same thing. Got advise from this forum, it turned out to be a vacuum line. replaced a the vacuum line from the tank and a rusted out break line and the issue seems resolved. Now have a new problem, I am sure I will get the needed advise from this site. The advise and information from this forum has been amazing so far.