The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-04-2003, 09:14 PM   #1
87r10
Registered User
 
Join Date: Jan 2003
Posts: 35
EGR Question

While on a run from Greenville to the Atlanta airport about 150 miles my service engine light came on. It didn't come on until after about an hour of running 75 to 80mph. Truck ran great even with the light on. Same thing happened on the return trip. I replaced the EGR solenoid valve about 6 months ago, had a cracked hose fitting. Wondering about an over active egr valve or maybe O2 sensor. I jumpered the test port and got a 34 (EGR). Doesn't do it on normal driving around town. Any thoughts or help is appreciated.
87r10 is offline   Reply With Quote
Old 08-05-2003, 12:52 AM   #2
swervin ervin
You get what you pay for
 
swervin ervin's Avatar
 
Join Date: Dec 1999
Location: Cherryville, NC
Posts: 4,798
I'm not a EFI specialist, but it's possible it could be the EGR solenoid too. I know the code says EGR, but this is a vague code. Anywhere in the EGR circuit could put up a EGR code.

Check all the hoses to make sure they are not broken or cracked. Clear the codes by unhooking the positve battery cable. Pull the plug on the solenoid and see if it sets the same code. Other than this, I wouldn't know what to tell you. I guess you could replace the EGR valve, but you may be spending money on nothing. If it were me, I'd replace the solenoid before replacing the valve.
__________________
Mike

1985 Chevy C-10
swervin ervin is offline   Reply With Quote
Old 08-05-2003, 09:02 AM   #3
87r10
Registered User
 
Join Date: Jan 2003
Posts: 35
Thanks for the advice Mike, I was kind of leaning that way also. Seems to me electronic stuff is more apt to break than simple mechanical things. I really don't like that emissions system. Wish I could trash it but don't want to go to all the expense. Thanks again.
__________________
Rusty
87, 350, 700R4
3/5 Drop
87r10 is offline   Reply With Quote
Old 08-07-2003, 06:17 PM   #4
apstguy
LED King
 
apstguy's Avatar
 
Join Date: Jan 2003
Location: Sacramento, CA
Posts: 2,088
I just got a code 34 and my book says it is the MAP sensor. I just accidently unplugged mine. The MAP sensor is on the passanger side of the firewall at the top just off center. The vaccuum hose is small so if you bump it it will come out of the fitting on the carb.
__________________
Tyler

1985 C10 305 w/ Bowtie OD TH700R4 3.42 LSD 202,000 miles
2006 Ford Focus ZX3 5-speed Stick
2016 Chevy Spark EV
Gone: 2002.5 VW GTI 24v VR6
Gone: 2008 VW R32
apstguy is offline   Reply With Quote
Old 08-07-2003, 06:48 PM   #5
87r10
Registered User
 
Join Date: Jan 2003
Posts: 35
Fault code

Hey Tyler, your right about the fault code. I looked in my repair book and had marked code 32 not 34, I incorrectly typed the wrong code from memory, should have known better!. You know they say your memory is the second thing to go!! Thanks for the heads up any way.
__________________
Rusty
87, 350, 700R4
3/5 Drop
87r10 is offline   Reply With Quote
Old 08-08-2003, 10:13 PM   #6
Grim Reaper
Registered User
 
Join Date: Jul 2001
Location: Atlanta GA
Posts: 1,704
If you get that code then it means it is NOT opening. The ECU see's a change in the O2 and Map when the EGR is open. If it doesn't see that for about a mile when driving steady speed it will throw that light.

It might be the passages are plugged up and causing it and not a problem with the controls. I have seen the port in the intake plug right below the carb in one. Not much different set up on a TBI.
__________________
Grim-Reaper
70 Pontiac LeMans Sport Convertible, worlds longest resto in progress
Looking for 71-72 2wd Blazer or Jimmy Project
Grim Reaper is offline   Reply With Quote
Old 08-09-2003, 12:00 AM   #7
swervin ervin
You get what you pay for
 
swervin ervin's Avatar
 
Join Date: Dec 1999
Location: Cherryville, NC
Posts: 4,798
Yeah, when I had the intake off my 87 305 in the van, that thing was caked up pretty bad. But the 305 has quite a few miles on it, so I guess it was time.
__________________
Mike

1985 Chevy C-10
swervin ervin is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 02:23 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com