troubleshooting p1294 - need advice

I have a 00' XJ 4.0 with around 150k.

I've been getting an engine light with code p1294. My idle at cold start has been around 700-800 rpm with some fluctuation and the idle holds the same when warm. So far I changed the IAC unplugged the battery to clear the code but I am still getting the code. I tried spraying some carb cleaner around the engine to see if I can find a vacuum leak but no luck. I plan to spend some more time to search for a leak tomorrow.

any ideas on what else I should be checking? The manifold and head gasket was changed not too long ago - could there be a connection?

Check all of the vacuum lines for cracks. How did the IAC port on the Throttle Body look? Clean or full of crud?

it was dirty so I just decided to replace it. On a cold morning should the jeep run higher RPMs ? Yesterday I checked again for a vacuum leak... I once again cleared the code to see if the error comes back

well the engine came back on again. My rpm gauge at idle fluctuates slightly around 750 rpms . Would using sea foam to clean out around carbon be a good next step? Trying everything I can on my own before taking it to the shop.

Sandydog said:

it was dirty so I just decided to replace it. On a cold morning should the jeep run higher RPMs ? Yesterday I checked again for a vacuum leak... I once again cleared the code to see if the error comes back

Click to expand...

0-gauge-steamer was asking if the IAC port in the throttle body was dirty. When I did mine, the port was filthy. It took some time to clean it out properly.

Here's the probable causes for P1294 (incase you didn't know already):


TEST A
You may want to remove the throttle body and give it a complete cleaning, then reinstall it with a new gasket - OEM P/N 53007543.

Excessive clearance of the throttle plate shaft in the throttle body may cause air bypass.