95xj everyday sputters, backfires through tb, wants to stall after startup only!!!

This only happens 1 to 2 minutes after startup when cold. If jeep is warm it wont do it. Have had problem for 6 months to a year!!!!

She sputters, bucks, backfires through TB, and stops in her tracks for about 30 seconds and then clears out, no matter if i put it to the floor or not and then clears out and runs like a top the rest of the day. engine light never comes on, but does work bulb is fine.

Things i have replaced

TPS sensor, new
IAC sensor, new
IAT sensor, new
Oxygen sensor, new only have 1
bosh efficent spray injectors
2001 xj intake manifold
charcoal canister
Map sensor, new
pcv valves on valve cover
pcv and vacuum lines
distributor
accel wires
accel coil
accel rotor
accel cap
new plugs
195 degree thermostat
TB spacer
pace setter header
pace setter cat high flow
pace setter cat back exhuast



Things that are original
crank pos sensor never replaced
knock sensor never replaced
alternator never replaced
ecu never replaced
fuel pump never replaced
fuel sock never cleaned

looked at my codes cycled key on and off like said.

check engine light codes are this

blink, blink, blink, pause then blink, blink, blink, blink, blink, pause then blink, blink, blink, blink, blink

Not sure what that means but that was it

What about temp sensor? It needs to know it's cold so it can richen up the mixture.

figured out my codes they are

code 12
then code 27 but thats injectors right? All 6 r new
then code 55

I have similar symptoms.

'98 XJ I6

Mine isn't backfiring but it is tending to sputter and not want to cooperate for the first 30 seconds or so of operation. It's also got an extremely long crank. Replacing the FPR and fuel pump seemed to help a little but the problem still isn't solved.

Hope someone has some suggestions!

Heck, replace the only thing left, the CPS. Get it from NAPA. And good luck with change out. Whoever put the thing up high on the bell housing should be :hang:.

PuddinHead said:

Heck, replace the only thing left, the CPS. Get it from NAPA. And good luck with change out. Whoever put the thing up high on the bell housing should be :hang:.

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Yeah, it would have been nice to have it up front somewhere. I guess they assumed that it would be a reliable part and not be failure prone.

Yea so far its just at start up it miss fires and runs or 4 or 5 cylinders. I left the battery disconnected from friday to monday.

Fired her up today and missed off the start engine light came on then the engine light went off 5 minutes later and jeep ran fine rest of 10 miles to wkork, i cleaned battery connections and put di-electric grease on all tps, iac, injector, temp and other sensor connectors to make sure the connections are good and that didnt help.

So this weekend i am replacing the CPS sensor, knock sensor if it has one and the temp sensor thats all thats left, then the ecu prob a junk yard one.

Try testing the coolant temperature sensor to see if it is in specs. It may be telling the ECU/PCM that the engine is warmed up, so you are getting no "choke" effect when cold.

Yea i forgot to add i ordered the temp sensor, with the cps so ill let you guys know what happens. what a pain

95cherjustin said:

Yea i forgot to add i ordered the temp sensor, with the cps so ill let you guys know what happens. what a pain

Click to expand...

I thinkk I'd change the temp sensor first. Its WAY easier to change and you might get lucky.

PuddinHead said:

I thinkk I'd change the temp sensor first. Its WAY easier to change and you might get lucky.

Click to expand...

I think I'd spend the $10-$20 and get a meter and test it first. Heck the $1.99 on sale meters at Harbor freight aren't too bad. Temp sensor is about the easiest thing to test.