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repl.pcv valve

  
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repl.pcv valve

 
tman1954 tman1954
New User | Posts: 1 | Joined: 11/12
Posted: 11/12/12
12:25 PM

car would not idle this morning found the hose off the pcv valve replaced still would not idle replaced pcv valve with new though it still rattled vehicle will not idle with hose on removed hose and it idles and runs smooth any suggestions know this needs to be attached also engine dies if you put thumb over the hose ,why would a new pcv valve not work and block the vacumn hose  

waynep71222 waynep71222
User | Posts: 155 | Joined: 04/12
Posted: 11/12/12
03:28 PM

a few things...   can you supply.. make model year engine and fuel supply type.. quadrajet, afb.. or fuel injection of some kind..

i have had terrible problems with aftermarket PCV valves that are boxed by SHAPE.. not by flow calibrations...  in as much as i could find... when you pinch off the PCV hose on a carb system.. the idle speed should drop between 50 and 70 RPM  if the PCV is calibrated properly for the application..


if you found the hose off the PCV and when you hook it up.. the engine dies...  i would be that you have some kind of fuel  injection system with a computer that controls the idle speed...

if the fuel injected engine is used to running with that much vacuum leak.. the idle air control will be commanded to reduce air flow to compensate for the vacuum leak...   so the system will need to RELEARN the new base idle and bypass percentage...

if you have fuel injection.. get it started and bring the RPMS to about 2500... then ever so slowly... let off the throttle..  if you do this over 30 to 45 seconds.. the computer will recalibrate the base idle and the bypass percentage to allow the engine to idle properly..

you could also have carbon build up on the throttle body and in the idle air control valve..

please... don't go crazy and start cleaning without specific instructions on how to clean it without ruining the Throttle position sensor or the idle air control motor..

year.
make
model
engine type
fuel supply type.. carb or injection..
what's been disconnected from stock..  

pepsi1 pepsi1
Enthusiast | Posts: 301 | Joined: 10/11
Posted: 11/12/12
07:13 PM

welcome aboard tman1954:

Follow Wayne's advice and he'll get you fixed up.