Quantcast




All times are UTC - 6 hours [ DST ]




Ask A Question Reply   
Author Message
 

contributions: 1
My 88 gmc runs good but has high idle, While a New EGR has screw in it. When I hooked Egr up, truck runs, Idle does come down, but when gas is applied the motor wants to stall or miss fire while driving.
Can my timing be off, Could use help finding this problem Please.


Share on FacebookShare on DiggShare on DeliciousShare on TechnoratiShare on TumblrShare on Google+
   
Reply with quote  
* Search   
 
User avatar

contributions: 1928
Images: 37
Location: Oregon
how high is your high idle? Most high idle problems are vacuum leaks. Unmetered air that causes the O2 sensor to go lean so the computer adds fuel to bring up the mixture that is no longer lean. So, more air and more fuel = higher rpms.

Small vacuum leaks will affect idle but are not usually enough to affect driveability because you are opening up the throttle so the vacuum leak is negated. If the engine runs fine with the egr plugged but runs poorly when the egr is hooked up to run normally, you should look at your egr circuit. There are different types of egr valves. Some egr valves hold vacuum, some do not. Some use exhaust back pressure, some do not. Installing the wrong type of egr valve will make the system operate incorrectly. Too much exhaust back pressure will cause some egr valves to be pushed open when they would normally be closed. Do a backpressure test to verify exhaust is clear.


   
Reply with quote  
Ask A Question Reply   


   Similar Topics   Author   Replies   Views   Most Recent 
New Articles View the first 2001 GMC sierra 1500 4x4 vibration in floor when acceleratin

in GMC Trucks

shackleferd33

1

841

Wed Nov 25, 2015 1:51 am

carriedi View the latest

New Articles View the first 1992 GMC Sierra 1500 4x4 dies w/out starter fluid constantly

in GMC Trucks

xyla

3

868

Mon Feb 16, 2015 11:12 am

carriedi View the latest

New Articles View the first 1998 Chevy Silverado 1500 Rev high smoking

in Chevy Silverado

tnb

1

1187

Thu Dec 04, 2014 11:06 pm

carriedi View the latest

New Articles View the first k5 high idle

in Chevy Trucks

ddafternoons

1

1640

Sat Jun 14, 2014 6:20 pm

carriedi View the latest

New Articles View the first 88 Blazer high idle

in Chevy Silverado

nutlug

3

1176

Wed Oct 21, 2015 11:01 am

carriedi View the latest

New Articles View the first 1995 c-2500 2 wd 5.7 l auto high idle, bangs into gear

in Chevy Trucks

kwbush

1

1414

Sun Jun 08, 2014 9:13 pm

carriedi View the latest

New Articles View the first Attachment(s) 1988 chevy Silverado

in Chevy Silverado

moparmaniacs

1

991

Thu Sep 03, 2015 3:06 pm

carriedi View the latest


All times are UTC - 6 hours [ DST ]



Search for:
Jump to:  
Contact Us