I’ve been reading the posts for days before posting…so if I missed something you all know about please link me.

96 Xj … new battery, new fuel pump, new upstream o2. Cleaned AIC, new TPS. New 4 hole injectors…new plugs and wires. Needed a lot of gas to get out of rough idle. Same thing has been getting worst after all those new parts. I suspect IAC…tell me if I’m crazy. She runs really rough at idle but the moment I take a vacuum hose off the intake manifold, she gets more air and purs like normal. AIC right? No cel

lots of soot on the o2 like she’s running extremely rich.

thoughts? Thanks.

 

1) How did you "clean" the IAC? Those things are pretty fragile. And, if it failed, cleaning it isn't going to fix it.


2)where did you get the injectors?

3) have you cleaned the contacts on the connectors at the IAC, TPS , map?

 

all look good.

 

It's a 96 so should be OBD II. Any codes? Can you tell from the live data if it looks like somethings driving it rich?
replacing the IAC is the parts cannon option but among things you never know how bad the new one is.

 

no codes…I think the big clue for me is the vacuum hose on the manifold…if removed, allowing more air in..starts up right away and idles smoothly. No stumble. Yeah…I cleaned the Aic, but like you said could’ve been on the Fritz already or I jacked it up more…

 

I bet the injectors are too big.

 

I would have suspected the same but the symptoms existed with the stock injectors as well.

 

The 2 things that affect the mixture the most, in order.

MAP sensor and Coolant Temp Sensor.

Look closely at the hose/piping to the MAP from the intake manifold. It can be cracked, melted shut or have pin holes in it.