Home page
  Home Page   Contact Us   Our History   Advertise with Us   Sponsor List   Link to Us   Compare Levels   Member Agreement   Privacy Policy   About C4VR
  Community Forums   Active Threads   Forum Search   Top Posters List   Private Messenger   C4VR Email System   C4 Corvette Quiz
  Members Vettes & Pictures   Member Stories   Member Stats   Real Time Member Map   Member Search   Member Calendar Entry Form   Who's Online
  C4 Registry Data   C4 Corvette Statistics   C4 Corvette Tips & Tricks   C4 Corvette How-Tos   Corvette Club Listing   Corvette Event Listing   Mechanic Directory   Corvette VIN Decoder   Save the Wave   Corvette Emblem History
  C4 Corvette Parts Auctions on eBay   Corvette Books   C4VR In-Stock Apparel & Accessories   C4VR Member Name Badges   C4VR Custom Apparel & Accessories @ Zazzle   C4VR Window Stickers   C4VR Member Calendars   Shop Amazon.com
☰
SPONSOR AD

Topic: Need to pass emission test

in Forum: C4 Engines

Already a Member? Click Here to Login

Need to pass emission test

Posted: 5/17/14 7:45am Message 1 of 3
ljcme
Standard Member
Send PM
Joined: 5/17/2014
Posts: 1
90 L98 90000 miles

I recently replaced my intake manifold gasket due to a leak at the rear wall.  Took my time and did a lot of cleaning at re-assy. Now I cant pass my emission test and it is hard starting (4 or 5 tries) when cold.

CO is 8.0 should be 1.2 max
HC is 350 and should be 220 max

I have rechecked for vacuum leaks and cant find any, PCV seems to be working well.

Any ideas where to look?

Thanks



SPONSOR AD:: (Our Sponsors help support C4VR)

Re: Need to pass emission test

Posted: 5/17/14 2:51pm Message 2 of 3
davep85c4
Former Member
Send PM
Joined: 4/4/2009
Posts: 254
ljcme said:
Any ideas where to look?

Thanks


 Be sure the MAP is connected to vacuum, and that the electrical connections on the MAP are tight and secure.
CO=8.0 is uber-rich. No vacuum to map or high MAP signal will cause this.



|UPDATED|5/17/2014 2:51:21 PM (AZT)|/UPDATED|



Re: Need to pass emission test

Posted: 5/18/14 11:59am Message 3 of 3
Big Mike 49
Standard Member
Send PM
San Jose, CA - USA
Joined: 5/10/2012
Posts: 81
Vette(s): 1988 Corvette / Blue Pearl

Oil Change ( used engine oil carries high amounts of Hydrocarbons ) New air filter , Check your timing also , I had issues this past year on mine & once I did these things  all the bad stuff was reduced & I pass with flying colors . I believe stock timing is set about  4 deg, ATDC.  I kicked mine down to 2 deg.






My Corvette Pic

in Forum: C4 Engines


SPONSOR AD: (Our Sponsors help support C4VR)