rough idle (EGR?)


Newbie600rr
06-26-2006, 05:55 AM
I have a 95 blazer 4x4 that has a real rough idle and has a little miss sometimes while driving. I thought it could be the egr so I took it off and cleaned it seened to help for a few day, but it came back. Could my EGR be bad causing a rough idle? And because of the rough idle,making my truck run rich and depositing more carbon into the EGR making my proplem worse. I tried looking and could not find any bad vac hoses.

ZL1power69
06-26-2006, 10:34 AM
your cpi might be starting to go. remove the upper plenum and check for washing (clean areas. should be all black if there are no leaks) or remove the imtv from the top of the intake and look down in there with a flash light. are u getting really bad gas mileage? have u replaced the cpi/nut kit before? check engine light on?

Newbie600rr
06-27-2006, 05:40 AM
I took off the upper plentum and I do have washing. On the passenger side rear. I also have code P1406 (EGR possition sensor performance). My gas milage is a little down and I have not replaced the nut kit. What it is the nut kit and will this help my problem or will I need to replace the whole spider assembly?

billibong
06-27-2006, 08:37 AM
Check out this link. It is the link for the spider replacement...
http://www.automotiveforums.com/vbulletin/showthread.php?t=559014
Hope that helps.

wolfox
06-27-2006, 09:49 AM
I would replace the entire kit under the intake plenum. Also, buy a new upper intake gasket, do not re-use the old one. I had to do this on my truck last fall, and everything to include nut kit, spider injector, gaskets (one for the EGR too) was obtained for a little over $340 complete. I took the EGR valve out and washed it up in carb cleaner, brushing out it's bore on the block with a bottle brush and carbretor cleaner. Once buttoned up, it was right as rain. EGR fouling can be a precursor to injector failure/leaking nut kit/leaking regulator because of the rich, carbon fouling exhaust the engine makes when it cannot control fuel delivery.

Also, change your oil when done. There is a lot of unprocessed fuel that washes down through the intake into the valvetrain and balance rod chamber through the lower intake bolts that dilutes the oil. This can lead to bearing failure across the board if left unchecked.

534BC
06-27-2006, 11:57 AM
My egr valve was recalled, It used to get plugged up frequently and now the new one has been fine for a few years. It was 95 eng code W. Electronic valve.

Newbie600rr
06-27-2006, 12:31 PM
Can you buy the complete kit from the local parts store or is that a dealer item only.

ZL1power69
06-27-2006, 12:53 PM
Can you buy the complete kit from the local parts store or is that a dealer item only.
check ebay for the cpi unit. the nut kit is a dealer item. i got both from gmpartszone.com

wolfox
06-27-2006, 12:56 PM
Find a GM parts dealer in town. My local GMC dealer made the mistake of telling me where they got thier parts stock, especially on CPI kits. I bought my spider for a little over $40 or so w/tax over the counter at a local retailer. :D Bought the injector while there too at a steep 50% discount over what the dealership wanted too. So hunt around, it pays to research a little and social engineer your local dealerships to find out whom backs them up. All parts were factory sealed, in the box, real AC/Delco - not some GP Soriensen (sp?) or third party aftermarket knock-offs.

Newbie600rr
06-29-2006, 05:43 AM
One last question. What is the Nut Kit?

Thanks for everybodys help

93LT
06-29-2006, 09:09 AM
Check out this link. It is the link for the spider replacement...
http://www.automotiveforums.com/vbulletin/showthread.php?t=559014
Hope that helps.


That is not the appropriate photo thread for this guy's 95 Blazer. The photos in that thread are for a '96 and newer.

Here is my thread with photos from my '93 Vortec (http://www.automotiveforums.com/vbulletin/showthread.php?t=473110), which will be identical to the vortec used in the '95 models.


There are no nut kits on the '96 and newer vortec (the nut kit is the fuel lines where they enter the lower plenum and run to the injector unit. As mentioned, check Ebay. There is a wholesaler on there that generally sells the nut kit, injector and gaskets as a set that is close to jobber cost. The wholesaler is a true GM dealer, so you will get a GM goodwrench reciept in case of failure of the injector within a year for a warranty replacement.

wolfox
06-29-2006, 09:49 AM
The nut kit is a set of fuel hoses that transfer the pressurized fuel from the back of the engine block through the intake plenum. Then, whatever's left over from the fuel regulator passes through a second hose to the back of the block where it mates up with the tank return line. So in essence, two, white, plastic, form fitted hoses, bracket and grommets. They also only go in one way having different diameters on the steel collars and grommets that pass through the block, and slightly different hose bends to meet with the regulator/injector assembly. It's hard to mess up. :D

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