Hello everyone. The problem I have is the high revs on start up. In the morning start when engine is 100% cold goes up to 2500rpm and if it warm up to 1900rpm-2100rpm. after starts and it drops immidiatly to 750rpm-800rpm.
Engine is mark VIII 4.6L 89k miles.
what have done before this post:
- TPS replaced and adjusted
- throttle plate cleaned and adjusted.
- IAC replaced
- MAS replaced
- Coolant temp replaced.
- o2 sensors removed and cleaned.
- fuel injectors removed, tested and cleaned(interesting fact when reinstalled injectors car first start on cold and rpm went up only 1700rpm.
- new air filter.
- engine rebuilt and replaced every single gasket except oil pan and transmission + re-timed with new timing kit.
- new oil, coolant flashed…
- smoked engine for air leaks -all good.
- EGR valve removed, tested, cleaned
- fuel pressure sensor disconnected and no difference but check came up after.
no check engine light all around.
I do not understand what else it could be.
Car has aftermarket exhaust but cats still there.
please help on any suggestion.
do not tell me it is normal because exact same car start up 1100rpm.