Did a timing belt job due to mileage and changed my coils and plugs due to a misfire. The misfire is now gone, but car runs like garbage. Whole on idle the rims drop to 500-600 and the whole car vibrates. Wot it feels good though. Should I try seafoam? I have a feeling that injectors might be dirty. Also car runs really rich wot. Afr goes up to 15.3 on idle. What is happening? I'm gonna try logging it next and post a picture of the log and ecuflash screenshot.

 

Have you done a boost leak test? That's where I would start if this just happened after you worked on it

 

Actually that completely crossed my mind. I'll get to it. Didn't see any spikes in boost wot but I'll double check

 

Im having a similar problem but for me it has resolved itself after a couple heat cycles. I drove the car 300ish miles straight and then when I pulled into my destination, i was blipping the throttle to keep the engine running because the rpms were going too low for the car to idle.

Now it idles fine with an occasional problem but it has only been a couple days after I had problems.

Hope this helps!

EDIT: Forgot to mention until user Ferp commented, relearning idle fixed the problem.

 

Does your car only run like **** at idle? Did you let the ECU relearn idle? If you have Evoscan and a Tactrix you can use the BISS actuator and make sure that is set properly too.

 

If it's tuned properly than there's no re learning to do.

 

It has a tune just not a proper one. Actually i did change the TB due to a leak, ill try adjusting the biss actuator with evoscan. Runs kinda rough at low rpms too up to 2500rpms.

 

If the car is still on a mass air flow system then it sounds like a boost leak.

Or could be a idle air control valve issue. For the idle.

Do you have a logger?

 

IAC should be good, swapped it out twice with no change. TPS is also good, and yes the maf if present. A logger? You mean evoscan and tactrix? If so then yes i do have it.

 

Ok well vheck your boost leaks before we go any further on the keyboard diagnoses.

Please dont do a visual and please do a real boost leak test and report back. Ok then. Log your fuel trims for 16 min.

 

Didn't know there was such thing as a fake boost leak test haha. All joking aside I'll try to get it tested for leaks asap. I have a tester laying around somewhere. Will report back within a few days.

 

Fake boost leak is you reporting back that there is no leak after doing a visual inspection.lol

 

Before you go somewhere and pay for any services
(Unless you do it on your own)
Check the Nipples on the Throttle Body.
If the THIN rubber hoses or Rubber Caps are OFF
You will have a Vacuum Leak which will change your idle drastically.
Usually these blow off when your in 4th-5th gear boosting -- going like 100mph and release the throttle. Happens to me ALL THE TIME. I bought rubber end caps at autozone.
But due to Weathering.. and Boosting.. they can crack or slip off.
After you look around for loose rubber hoses.. and find NONE.
Go do a boost leak test which will detect these anyway.
But some places charge like $30 for this or even more.
So if you can find the Vacuum Leak on your own and plug it in..
You'll be thrilled and how easily that fixed the problem.

But! There are many places were these small rubber hoses connect to.
At least this is the issue for the Evo 8/9's. But i cant see how it would differ much on a X.

Hopefully you solve the vacuum leak.. but obviously a boost leak test is the next step and should be done regardless to ensure everything's on point

 

Update. Did the boost leak test. Large leak in the tb gasket and a small leak in the piping (clamp not tight enough), also 2 of the hoses behind the intake manifold were completely off. fixed both things but still seeing the same thing. Car does feel slightly smoother and It feels like I got 30+ HP back, but still feeling that rough idle. My car died on almost every stop sign, no change when it got warmed up.

Another Update. CEL popped up, P0446, something to do with EVAP. Tried doing a log while stationary, car died every time after i gave it a rev past 4-5k rpms.

 

I think it's a bad tune. Timing advance goes up to 46 wot, and i got 4 counts of knock at one point. Tps is always at 15 when off trottle, shouldnt it be at 0? AFR is at 14.7 on idle. What else should i be looking at during the log?