Green Bastard Posted July 3, 2012 Report Share Posted July 3, 2012 like the title says, i have a 99 blazer and it surges. it doesnt do it at idle or full throttle, more around 2k rpms and steady cruising speed. it does have a cel and i had that checked, it came back with three codes all saying there was a bad switch or sensor in the evap system. could this be the cause or is it something else. it doesnt run bad at idle so that leads me to believe its not a vacuum problem. it runs pretty good but the surging is starting to get on my nerves. if anyone has expiranced this before any info would be greatly appreciated. fwiw its a 4.3 vortec motor. Quote Link to comment Share on other sites More sharing options...
Cordell Posted July 3, 2012 Report Share Posted July 3, 2012 Surging huh? Do you actually have the codes? Those things are bad about a few things (like the spider injector shit, and crappy flat distributor cap), but I don't really see these things surging. Could it be descibed as missing or stumbling? Quote Link to comment Share on other sites More sharing options...
Green Bastard Posted July 3, 2012 Author Report Share Posted July 3, 2012 no, its a surge, when the throttle is held steady its like your pressing the gas and letting off just a little. its about a 500 rpm surge. there is no miss though. i cant remember the code, but it said it was the evap system. i wanna say 0430 maybe? could be wrong though. Quote Link to comment Share on other sites More sharing options...
MrMeanGreen Posted July 3, 2012 Report Share Posted July 3, 2012 My '99 Blazer did that as well. Ended up being a stuck EGR valve. Quote Link to comment Share on other sites More sharing options...
Cordell Posted July 3, 2012 Report Share Posted July 3, 2012 P0420? P0430 isn't one commonly used by GM, those codes relate to the cats not the EVAP system. Cats going bad should cause a defined stumble when they get bad enough, if that is even the right code. I suppose if were mine I'd clean out the throttle body and IAC valve, best done with the parts removed for a thorough cleaning. You can try that and see if it makes a difference. Quote Link to comment Share on other sites More sharing options...
Green Bastard Posted July 3, 2012 Author Report Share Posted July 3, 2012 ill give it a shot, ill also see what i can do with the egr. thanks guys, ill let yall know what happens after i clean those things. Quote Link to comment Share on other sites More sharing options...
Large Posted July 6, 2012 Report Share Posted July 6, 2012 my lt1 does a very similar surge,yet not near as many rpms,maybe 50rpm. just enough to notice it.very annoying.scanned it and the code said evap. but i know nothing about EGR systems. not sure what to do. Quote Link to comment Share on other sites More sharing options...
mjrsplat Posted July 6, 2012 Report Share Posted July 6, 2012 You could start by not hijacking someone else's thread. :gtfo: Quote Link to comment Share on other sites More sharing options...
351mach11647545510 Posted July 7, 2012 Report Share Posted July 7, 2012 You could start by not hijacking someone else's thread. :gtfo: wtf are you talking about Quote Link to comment Share on other sites More sharing options...
Green Bastard Posted July 7, 2012 Author Report Share Posted July 7, 2012 I'm pretty sure the evap system is leaking, when the blazer is running it smells like gas sometimes, and I saw what looked like vapor come out from under the truck. I'm gonna crawl under it tomorrow and see if I can pinpoint the leak. I got a can of carb and choke cleaner and cleaned the iac with no luck. Quote Link to comment Share on other sites More sharing options...
Large Posted July 7, 2012 Report Share Posted July 7, 2012 how is your idle? Quote Link to comment Share on other sites More sharing options...
Green Bastard Posted July 7, 2012 Author Report Share Posted July 7, 2012 steady at 650 in park, 600 in gear. the surge only comes on at part throttle. Quote Link to comment Share on other sites More sharing options...
Green Bastard Posted July 15, 2012 Author Report Share Posted July 15, 2012 ok, I cleaned the egr with no luck. the more I read about it though it sounds like a tcc solenoid. does anyone know the part number I would need for a replacement and/or a link on a writeup on how to replace it? Quote Link to comment Share on other sites More sharing options...
351mach11647545510 Posted July 15, 2012 Report Share Posted July 15, 2012 its part of the tranny's harness. the whole harness has to be replaced. its a $60 part if i remember right. drop the pan, remove connectors from the other solenoids, use a socket (dont remember what size) to depress the tabs to the main harness plug to pull it out the bottom of the case, and unbolt the tcc solenoid. Quote Link to comment Share on other sites More sharing options...
351mach11647545510 Posted July 15, 2012 Report Share Posted July 15, 2012 http://www.wwdsltd.com/4L60/4L60EValveBodyBoltCodeLg.jpg Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.