08-05-2010 | #1 |
Join Date: Aug 2010
Location: ottawa canada
Posts: 156
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long crank puff of blue
Experiencing long crank and blue smoke on hot start.
If the restart occurs within approx. 10 minutes, starts fine no smoke but problem if left for a longer period. Once it fires it runs smooth & strong. Replaced OEM injectors with RC's 2 years ago. Has anyone else experienced this? have any knowledge on this issue.? Thanks: |
08-05-2010 | #2 | |
Join Date: Oct 2004
Location: Folsom CA
Posts: 1,653
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Re: long crank puff of blue
Quote:
What year Z? How many miles? Mods? Fairly common for '90s as they have no valve seals on exhaust valves. TomC "Crabs
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TomC '90ZR1 #792 Honorary Pirate [B]If it ain't FUN, you're doing something terribly WRONG. [/B] Last edited by tccrab; 08-05-2010 at 12:10 PM. |
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08-05-2010 | #3 |
Join Date: Aug 2010
Location: ottawa canada
Posts: 156
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Re: long crank puff of blue
'90 - 25000 mi.- completely original.( except RC inj.) No smoke on hard acceleration --smoke & long crank on hot restart after shutdown time of more than 10-15 minutes.
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08-06-2010 | #4 |
Join Date: Dec 2003
Location: Chicagoland,IL
Posts: 2,679
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Re: long crank puff of blue
Sounds normal to me.
1990 ZR-1's do not have exhaust valves seals so they had the common small block chevy issues, smoke at start up. It's also common for LT5 for long crank start up,just make sure you crank her till she starts. Pete
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'91 #1635 PoloGreen 350 LT5 11.09 @ 129.27 11.04 @ 128.86 474RWHP 400RWTQ http://www.youtube.com/watch?v=SFNFOhGGlR4 http://www.youtube.com/watch?v=ZlRIOMwaDYY https://sites.google.com/site/peteszr1garage |
08-06-2010 | #5 |
Join Date: Aug 2010
Location: ottawa canada
Posts: 156
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Re: long crank puff of blue
Since it's a one owner car for 20 yrs. & I have never had this problem until recently I felt it was not normal. Consenus so far is that it is normal due to lack of exhaust seals so maybe I have to live with it but if seals are the issue why no smoke on hard acceleration (WOT)?
Only on hot shutdown restart Thanks to Tom & Pete for their input. Last edited by geezer; 08-07-2010 at 09:29 AM. |
08-06-2010 | #6 | |
Join Date: Oct 2004
Location: Folsom CA
Posts: 1,653
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Re: long crank puff of blue
Quote:
When the engine is new the tolerance are too tight to allow oil to seep past, however as the engine wears those tolerances loosen up and oil sneaks past. I've read that it's possible to machine the heads and add valve seals to cure that little puff of smoke. However, it would mean taking the heads off and all that entails. Seems like a pretty big expense for a fairly minor issue. The other option is to sell the '90 and buy a '93-95 with the 405hp engine that has valve seals. Again, a pretty drastic solution to a minor problem. TomC "Crabs
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TomC '90ZR1 #792 Honorary Pirate [B]If it ain't FUN, you're doing something terribly WRONG. [/B] |
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08-06-2010 | #7 | |
Join Date: Jul 2005
Location: Mendota Heights, MN. 55120
Posts: 984
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Re: long crank puff of blue
Quote:
My '90 with 72K does smoke at hard acceleration and down shifting at high revs.
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Bob Anderson 1990 #2405 White/Gray Haibeck chip,4:09 gears,Power Effects Exhaust,5 spoke chrome,C5 brakes,49th Street rockers,K&N,Hurst,Headers,Upper & lower ported Minnesota State Director Founding Member #19 |
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