Ever since I bought my '99 Blazer 4.3 Vortec 4x4 the service engine soon light has been on. I've also had to pump the gas 5-6 times before cranking to get the engine started. After reading a post here a few days ago my problems have all gone away. Thanks guys/gals. It seems by turning my key to the on position for a few seconds before cranking has let the engine start without pumping the gas. Less than 24 hrs later the Service Engine Soon light also went out. Any answers as to why are appreciated.

 

When you turn the key to the 'on' position you are allowing the fuel pump to prime the system, which is the correct way to start the engine. Too bad you did not get the SES code read before it cleared itself. If it shows again, have it read and let us know what it was.

 

The fuel filter probably needs replacing. The SES light is probably related to a EGR valvemalfunction. At least that is the most common reason for a SES waring light on the 1st generation S10 Blazers and pickups. The SESlight may come on when the EGR valve is stuck with carbon deposit and will go out ten seconds after the ignition is turned off.My 1991 S10 Blazer was having that problem after a lot of city driving. I just drove the SUV at 80 - 90 MPH for abut ten miles and the SES light has not reappeared.

 

You can still get it read. The puter stores the codes for like 50 starts.

 

The EGR circuit error isOBD-1 code32. After vacuuming outthe carbon deposits at 90 MPH and after restarting the engine one time, and the SES light has never reappeared. I never checked the OBD-1 diagonsitic codeafter that.

 

The OP has an OBD II truck...it's a '99...so OBD I stuff doesn't apply.

 

I am aware of that. However, the80-90 MPH solution DOES apply. I don't know what the OBD 2 trouble codes are butthe appropriate appriopriate trouble codes do apply.

 

Thanks for advising others to break the law. Good advice...[&o]

You can clean the EGR valve quite easily. While you have it off, plug the port that runs into the intake plenum and start the engine. All of the loose carbon will come flying out so do not be standing in front of the truck. Be quick though and shut it down right away. If you really want to get it cleaned out, you can get a brass bristled pipe cleaner with a long wand and push it down the exhaust supply port. Then start it with the EGR valve off.