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Calpastor 09-12-2013 12:02 AM

1990 Wrangler YJ 2.5 liter with TBI --What Next?
Started stalling, backfiring, idling rough...
I changed plugs, wires, cap, rotor - No change
New Battery - No change
New coil - No change
New Fuel Pump and Filter - No change
New Crank Position Sensor - No change

Que89YJ 09-12-2013 05:43 AM

Does it make any difference in the way it runs hot or cold?

Calpastor 09-13-2013 11:24 PM

1 Attachment(s)
Cold runs better...but warms quickly and then runs bad...
I replaced throttle body injector today - No change
What's this part?

Attachment 674721

ShArKtRaInEr 09-14-2013 12:46 AM

Check for vacuum leaks, like behind the engine where the trans meets. There is a junction there. Also you can check the oxygen sensor and throttle position switch at the back of the throttle body.

That photo is the idle speed motor. You can reset/retract it with a little 9V battery, the two center pins are where you connect after disconnecting the harness.

Que89YJ 09-14-2013 04:52 AM

If there is a big difference hot to cold then o2 or coolant temp sensor. Not the one for the guage. Can't figure out where you took the pic?

Calpastor 09-14-2013 10:49 AM

Not a big difference hot to cold.

I do have an exhaust leak...could that cause the proble?
I may replace TPS today...what about EGR? Could that creat idle issues?
Pic was Idle Control Motor

Calpastor 09-14-2013 10:47 PM

Added new throttle position sensor - still rough idle
I have an exhaust leak on exhaust manifold...couple bolts missing, could that create a vacuum leak?
I'm also wondering about EGR valve, but it's about 110 to replace. Ouch!

Que89YJ 09-14-2013 11:52 PM

The exhaust leak is throwing off the o2 sensor causing you to run rich and throwing off the calibration. On the pre 91 yj there is a setup procedure that must be done for the tps, ais, and wot when replacing.

Calpastor 09-16-2013 12:09 AM

I'll update after that.

Calpastor 09-30-2013 09:21 PM

Feeling dumb, and angry.

Bad Spark Plug! Not cracked, not broken. I changed plugs, wires, rotor, and cap when my engine started running rough. And it didn't help. My mechanic removed plugs and tested them and found one that just was a dud. Running like a champ now!

Chrisnvegas 09-30-2013 09:59 PM

That was one expensive spark plug!

The time now is 12:56 AM.

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