Carbon Buildup/EGR Probs

[XtremeXP]

It was the first time I've ever replaced one. Wasn't too bad and yes take the upper intake off. Took me maybe 3 hrs to do. The cpi was a little over 200.00 at a local parts store. I bought a repair manual and it's came in handy also. So I would recommend buying one if you do alot of your repairs yourself. They also suggest to replace the internal fuel lines but the dealership had to order them and it would've taken 3 days to get so I skipped them and haven't had any leaks or problems. It looked like it would've been more difficult to replace them anyway.

[Firstlady5610]

Sorry. XtremeXP, but what is this cpi (regulator side) ? I have looked in the GM (Chilton's) and they don't mention it in the book. I took my EGR valve off and leaned it up. Worked fine for a week. Now it is back at it. Now I do the screen and cross my fingers. I don't have the $ 270.00 the cpi.

[Firstlady5610]

Wow now take the manifold off hu? ok well then I guess I run it for the week and save the money up and try next weekend.

Thank you !

[rlith]

the CPI (central port injection) unit is your main injector unit... www.lindertech.com sells just the regulator for it ($99.00) chich is usually the part of the CPI that goes bad...Pull your upper plenum (upper intake) and look for signs of washing (where one side is cleaner than the other) If the passenger side is washed, your CPI is bad, if the driver's side is washed, it's your nutkit (inbound/outbound fuel lines inside the plenum)

[rlith]

here's the direct link, about 1/2 way down the page, they also sell the nutkit

http://www.lindertech.com/reconinj.htm

[dolfo]

I have a 96 4.3 that has been idling rough for the last 5 yrs. I've had the fuel injectors cleaned and then replaced but it still idles rough. Reading through some of the posts I discovered that carbon can keep the EGR valve open. I took out the EGR and sure enough I could blow through the valve. After tapping, scraping and spraying with carb cleaner it finally sealed. After re-installing, the car ran much better for a few days then started to get worse. I pulled the valve again and it had a lot of carbon in it again and wasn't closing properly. I went and bought some Seafoam motor tuneup , available at NAPA auto stores, http://www.seafoamsales.com/motorTuneUpConsumer.htm which I read on some posts did a great job of getting rid of carbon build up. After all the smoke cleared I took it for a drive and it was more responsive and seemed to have better power. I also put some in the tank and after I empty the tank I'll install the gasket for the EGR that I made with a fine mesh screen from my wifes tea ball ( she'll never miss it!) sandwiched between 2 EGR gaskets with RTV sealent. This is supposed to keep the big chunks out of the EGR valve to keep it running smooth . I also ordered some Auto-RX to run through the engine. It's supposed to do a great job of cleaning out all the sludge and gunk that builds up in the engine along with freeing up stuck rings helping valve guides and engine seals, improving gas mileage and make it run smoother. It sounds to good to be true but considering how much I've spent on Mechanics and unneccesary parts another $25 will be a bargain if half the claims for it are true. Check it out http://140.239.139.96/ARXforums/ . Will let you know how it turns out.

[tomminajar]

Be prepared to drill out the Torx bolt that always breaks that hold the fuel line to the back of the manifold...

[95xjsport]

I know this is am old post but, where is the egr valve??

[blazee]

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