Full Size K5 (1969-1991) GMT415 (1992-1994) Tech Discuss any and all full size K5 general tech topics here.

[email protected]%&*! What the

Old 03-30-2015, 12:18 PM
New Member
Thread Starter
Join Date: Aug 2011
Posts: 7
nzvlnr is on a distinguished road
Default [email protected]%&*! What the

History: 1994 blazer 4x4 5.7 ltr. I passed smog in 2013 with flying colors. New catalytic converter has to be replaced. Prior to that ..I replaced the EGR valve, 02 sensor, cap rotor, plugs wires, rebuilt the TBI unit...it would not pass. Once the CC was put in...tech said it was running really clean... I dont drive the truck too often and I just replaced the battery 1 month ago...I drove it for about 25 minutes and took it in for a smog check....and did not pass...the tech said it was running really rich.....I am pissed!! Could replacing the battery take the computer out of code it is making it run really rich..? This sucks ...I just want it to pass so I can sell it....I live in CALIFORNIA..
Please advise.....This blows!!!
other replacement parts: New fuel pump,
Old 06-23-2015, 01:13 PM
Beginning Member
Join Date: Jun 2015
Posts: 10
Es_81k5 is on a distinguished road

If you could get it hooked up to a scanner and pull some data that would help. It could be from a bunch of things but I would start with getting data. You could also check the plugs to see if any of them are discolored dark. Anything darker than a light brown indicates it is running rich. In a TBI engine that could be caused by very dirty injectors dumping fuel rather than spraying it in a cone like spray, bad pressure regulator, and/or bad O2 sensor. It may be worth just running some good fuel system cleaner (I prefer sea foam) through it to see how it acts after that is done.
Old 06-23-2015, 02:09 PM
LeWhite's Avatar
Senior Member
Join Date: Nov 2012
Location: under Los Angeles
Posts: 836
LeWhite will become famous soon enough

I would say that it is a temp problem. Sensor thermostat or you didnt run it hard enough to rebuild the fuel map.
Old 06-23-2015, 02:26 PM
Beginning Member
Join Date: Jun 2015
Posts: 10
Es_81k5 is on a distinguished road

You're absolutely right that it could be a temp issue as well. Normally in TBI engines if the coolant temp sensor is bad or reading cool enough to run rich like that the gauge will have problems with reading correctly as well.
Related Topics
Thread Starter
Last Post
Audio/Video Electronics
10-18-2015 10:48 AM
2nd Gen S-series (1995-2005) Tech
01-19-2015 03:03 PM
Full Size K5 (1969-1991) GMT415 (1992-1994) Tech
02-11-2010 07:40 PM
1st Gen S-series (1983-1994) Tech
12-22-2006 04:10 AM
Headers, Intake, & Exhaust
10-07-2006 11:59 AM

Thread Tools
Search this Thread
Quick Reply: [email protected]%&*! What the

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.