Annoying idle issue

[2skippy]

I have a interesting idle issue, from a cold start it'll start at 1000 rpm then as it warms up it sits perfectly at 800 rpm. However if I drive it around for a bit then park it and come back to start up while it is still warm she has issues, starting at 800rpm dropping to 200 rpm and almost stalling, it will continue this way every time I hit the clutch until everything gets back to normal operating temp then it goes back to normal. It is a 6-bolt swap with full emissions delete, including the FPS. I have checked the TPS and IACV, both seem to have normal resistance. I'm making a BLT and will check for leaks in the morning (I have 14-15 mm/Hg at idle). It is my understanding that the FPS aids with hot starts, but having an upgraded fuel pump will help (I have an Evo 8). Is my pump just not helping enough or should I be looking in a different direction. I was told that adjusting the timing off the CAS could help but I have no idea how to do that properly and really don't want to break something important (this is my DD) . Any help would be appreciated.

 

[dkalfop]

There are some things that you might want to look out for; first check the idle screw on the throttle body, turning counter clockwise to increase the idle (I might be wrong about which way to turn the screw. Another thing is to remove the intake pipe to the throttle body and clean it with spray cleaner. There is always a chance that you have a vacuum leak somewhere. Also removing the all the emissions system might have caused the low idle.

 

[Tiki2777]

this happens to mine as well... i wish someone would come up with an answer
(mine has a high idle bounce until it warms up too)

 

[2skippy]

^ I know, it truly is frustrating.

 

[Gst to the max]

My gst does the same thing, first morning start up it takes two cranks to get it to run. I have to let it sit and idle for a good five minutes before I can touch the throttle and it not want to kill its self I wish I knew the problem.

 

[sek_phok]

Check for any vaccume leaks and also check your spark plugs, wires and coil pack.

 

[Gst to the max]

Both coil packs on my car are brand new, along with ignition control module spark plugs and wires. I've checked for vacuum leaks and have found nothing. I even cleaned the idle air control sensor and it gave it better throttle response but didn't solve the problem.

 

[Dvcaptainm]

Just because the packs are brand new doesn't always mean they are ok, I have bought many parts new that either didn't work or died shortly after install, I would check them anyways

 

[Gst to the max]

I know what your saying, the only reason I have faith in my coils is my car was running on two cylinders due to a bad coil so I went ahead and replace all the ignition stuff under the hood

 

[jtmcinder]

OP: next time you're about to start the car when it's already warm - i.e., when you have the problem - spray or ice down the fuel rail before you start the car. See if that prevents the problem. If it does, the solution is a phenolic spacer between the head and intake manifold.

 

[Gst to the max]

I never thought about that. I'm still new to tips and tricks what exactly would u recommend for spraying the fuel rail.

 

[2skippy]

Same question, what would you recommend spraying on the rail, the won't damage the wiring

 

[Gearhead4G63]

Had the same issue check for vacuum leaks boost leaks, and check the throttle body, if the three vacuum lines are off or leaking it will do that as well.

 

[Gst to the max]

I've gone over my clamps 100 times, there all tight couplers and all. They only thing I haven't checked is the the throttle body. What I can see of the three lines on the throttle body they are conected with no leaks. One thing I havent considered in the throttle body gasket. I'm installing a 70mm s90 throttle body soon with new gasket. If that's the problem should be fixed then.