EGR replaced 4x

I first replaced EGR at 60Kmi, then 110mi, then 125, then 137, now at 140mi. It's starting to idle rough again, and fear another replacement in future. There must be something causing this continuous carbon buildup and EGR failure. The engine has been cleaned each time EGR was replaced. A mechanic stated once carbon starts, there's no way to remove all the buildup. Anyone have ideas?
I read a message somewhere on this forum stating they replaced their EGR at least 3x or more. They suggested to use the Tomco EGR gasket which apparently helped the problem. Has problem returned or completely resolved? How many miles now on the Blazer?

excluding an outright failure of the EGR valve, you don't need to replace it each time. simply cleaning it will do. set the base of the EGR valve in about 1/4-3/8" deep pan of carb cleaner and let it soak a bit, then brush it good with a small wire brush, and rinse the base off with cleaner again.

just be careful not to soak the entire thing, only the base.

the frequent nature of your problem seems a little odd, as i have a 95 S-10 w/CPI (same EGR) and ive only had to clean mine once in 180,500 miles. makes me wonder if its a result of the gas blend available where you are (there are about a dozen different blends) or if its the fact that i always have my foot buried in the pedal, helping keep the carbon blown out.

havent used the screened gasket, so i cant help ya on that one.

also, dont rule out things like spark plugs, wires, CPI injector(if it hasnt been replaced) etc. causing your latest round of rough idle.

It's been serviced by dealers and Goodyear shops, both who 1st tried to clean, but unable to unstick the valve. I began using fule injector cleaner every oil change after the 125K change, but obvioulsy didn't prevent the problem.

I live in CA, apparently lots of additives to the gas. I'll try your "Peddle to the Metal" theory once in awhile. With price of gas in CA, that can get expensive :)))
By the way, what is the CPI injector unit you mentioned?
Thanks for taking your time to respond.

the CPI injector, is the fuel injector assembly. they are prone to leakage, and can effect idle, gas mileage, drivability, etc. the fuel lines that are inside the intake can leak as well. to totally run out leakage of either of these, usually means removal of the upper plenum of the intake, or some have removed the manifold tuning valve in order to look inside.

as for the dealers cleaning the valve first, unless you actually watched as they did so, i seriously doubt they did that.

i have a friend that a GM tech, he said they replace'm all the time, but that a good cleaning is all they probably need. they replace them just to help insure it doesnt come right back for the same thing.

Just recently recorded approx 20mi/gal, with city driving mixed in there. It's running smoother since I gave it a kick several times. Thanks for advice. It seems even these older vehicles need a reved up occassionally.

One other point of curosity, does your 4x4 control panel buttons still work at 180K. I no longer have lighted control buttons, and it won't engage into 4x4 mode.

my pickup is 2wd.

however if the lights on the switch dont work, then i'd start by checking the fuses, and the switch itself.

My 4 wheel drive still works with 201,000. I activate it every so often just to make sure it engages and disengages.

I use a Tomco EGR gasket screen, as I used to get carbon build up and had to clean the EGR too many times, its dangerous as the brakes and idle are so rough that you can literally crash your truck. my truck still idles rough at times, I have changed the cap and rotor, wireset, 02 sensor, CPI injectors, etc at this point It seems like I have a rebuilt truck .

The Clean screen seems to have helped me, I thought it would clog up but Tomco assured me that carbon would be caught and burnt off by the intense heat produced by the exiting exhust. - lies or not ? I still have no little phucked up "Service engine soon light" glaring at me.

hope that helps ya and I agree with cobra1's posts

Thanks Scooter, IOU, and Cobra for all your comments. Looks like I'll be calling Tomco for a purchase if it fails again.

Scooter, how many miles on your truck and miles since last cleaning EGR and installing the screen? Since screen install, have you been using injector cleaners or some other type of regularly cleanings. Do you live in CA, where many gas additives are used?

Seems to me like GM had a service bulletin on these that had a prom replacement or ECM reprogram that had a deal that would open the EGR valve wide open at a certain time to clear it out each run cycle, timed to not affect driving. Might have your dealer look the TSB list over for this, but maybe they just like to sell you new parts, worth a try though.

Yep there was TSB on that egr valve

Thanks Scooter, IOU, and Cobra for all your comments. Looks like I'll be calling Tomco for a purchase if it fails again.

Scooter, how many miles on your truck and miles since last cleaning EGR and installing the screen? Since screen install, have you been using injector cleaners or some other type of regularly cleanings. Do you live in CA, where many gas additives are used?

Hey bro,

One thing you need to know, you don't have to replace the EGR valve everytime it has a piece of carbon stuck in it.

Just remove it, clean out the chunk of carbon, spray it out with throttle body cleaner and reinstall it wil the $2 EGR gasket. Dealers and mechanics just love to replace the valve and charge you the full price when it is just not required.

Also, I wouldn't install the screened gasket seeing you want to get the carbon out of your truck engine and you don't want it trapped inside.

As cobra1 stated, the carbon buildup could be in part due to a leaking CPI unit or a leaking internal fuel line kit called the nut kit.

A quick check is to remove the top vortec plate on to of the engine, remove the round IMTV valve in the top of the plenum and take a flashlight and peer inside and looked for washed golden spots, pool of gas and the strong smell of fuel.

Here is some informational reading for you:

http://www.asashop.org/autoinc/feb2000/techtotech.htm

http://www.s-seriesforum.com/forum/showthread.php?s=&threadid=34668 <--register, it is worth it for the pictures and replacement guides.

Also, here is mine experience with some excellent photos for you.

http://www.s10forum.com/forum/showthread.php?t=113559&highlight=cpi+replacement

Enjoy!