Major issues that I can't figure out...
- Thread starter 90xjowner
- Start date
SteelHeadz
Super Moderator
Check the fuel pressure and for vac. leaks on the base and gasket of the intake manifold.
so get this... I went and bought a heynes for my xj and was reading into it and happen to notice the firing order pattern... low and behold, ever since I bought the jeep say 4 years ago the firing order has been off.... How its been running all this time is a mystery to me. but now that it is running it is still running very rich and starts to bog down and stumble about mid throttle and higher any ideas? and thnx for the help i wouldn't thought to check for vacuum leaks i have a couple issues that need to be checked their as well.
MudderChuck
New member
I'd check my CPS and the vacuum line for the MAP sensor. Though I've not noticed the MAP causing backfire through the TB. A disconnected or leaking MAP vacuum line will cause it to idle really bad and stall and barely accelerate.
First thing to check with the CPS is that the wires aren't cooking onto the exhaust manifold and the connector is clean. Then an ohm test.
Mid throttle bog is often an O2 sensor, but can also be a TPS. Various sensors work together, one goes bad or gives false values, it's sometimes hard to tell which is acting up.
I went down years ago and pulled a set of junkyard sensors out of an XJ the guy told me was driven to the yard, sure helps troubleshoot when your stuck. Though to tell you the truth it is the wiring or a connector as often as it is the sensor itself.
I've had mine backfire through the TB, because of bad spark plug wires and a bad distributor cap. Some of my sparkplug wires had infinite ohms, my cap was covered inside in carbon dust and was arcing.
First thing to check with the CPS is that the wires aren't cooking onto the exhaust manifold and the connector is clean. Then an ohm test.
Mid throttle bog is often an O2 sensor, but can also be a TPS. Various sensors work together, one goes bad or gives false values, it's sometimes hard to tell which is acting up.
I went down years ago and pulled a set of junkyard sensors out of an XJ the guy told me was driven to the yard, sure helps troubleshoot when your stuck. Though to tell you the truth it is the wiring or a connector as often as it is the sensor itself.
I've had mine backfire through the TB, because of bad spark plug wires and a bad distributor cap. Some of my sparkplug wires had infinite ohms, my cap was covered inside in carbon dust and was arcing.
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