low idle when warm

[srx901]

Ok I have a mpi 180 turbo with pcv pti installed I am having a low idle when warm condition. I have changed plugs, gas checked for vacuum leaks, replaced the isc valve, checked and replaced the TPS, checked the sensors on the trottle body, cleaned and sync throttle bodys lowered co to -8 on each cylinder, changed map sensor for pcv, checked compression and over 200 each cylinder less than 5percent leakdown. I have A-F gauge and when sled is warmed up and the idle starts to dip my A-F readings lower which means its getting richer. Anyone have any other ideas. Oh and I unplugged the PCV and ran the sled on idle and it act the same.

 

[herndonp]

ISC controls idle. Check this thread out for testing.

http://ty4stroke.com/threads/idle-speed-control-valve-isc.86127/

Goodluck
Pete

 

[Big_Phil]

Mine does the same thing, but i also have 430cc injectors. Thought that had something to do with it. Sometimes it idles perfect, sometimes it dips low, no idea why. I changed plugs and swapped coils with a good running sled. Same thing, i gave up and just deal with it now.

Helped somewhat when i lowered my fuel pressure at idle, but you dont have that option with your 180 kit.

 

[grizztracks]

A little more added information. The ECU was swapped with one out of a Nytro with no issues and there was no change. The wire harness was also inspected and no noticeable bad spots detected. The only two thing that haven't been checked or swapped out are the injectors and fuel pump.

 

[grizztracks]

I'm wondering if the injectors are leaking and at the lower pulse frequency it's more noticeable.

Symptoms of leaking fuel injectors:

1. Hard Starting when engine is hot.
2. Increased Fuel Consumption.
3. Rough Idle.
4. Fuel odors.
5. Poor Emissions.
6. Oil thinning, which can lead to catastrophic engine failure.
7. Hydro-lock, which can lead to catastrophic engine failure.