stuttering/shaking problem

[badluckbravada]

Help!!! i have a mind of its own 94 olds bravada. it has 128000 on it and when its idling it kinda acts like its going to stall for a sec and then comes back and then does it again, when it stutters it shakes too. it doesn't just do this while idling though it does it when your driving especially around 50-55. the weird thing is i let it sit for like a month and a half and then started it up and it ran fine, now a week later its doing the same thing, help i just want to get it to run good so i can get rid of this piece of bad luck!!!

[Chris Stewart]

Is the check engine light on?

[badluckbravada]

nope no check engine lights or anything, my dad thinks it might be just the fuel filter is clogged or maybe the erg or egr and whatever the heckk its called valve so he gonna check them today and then if that doesn't work i'm going to take it to a shop to have them run a diagnostics check on it and see what codes might come up....oh ya it stopped doing it again today after it sat for a day, when it acts up though it feels almost like it feels when ur running out of gas like that sputtering lurching feeling just not quite as bad...

[Chris Stewart]

Does the check engine light come on when you first turn the keyswitch on then go off after a coupla seconds?

[badluckbravada]

yes but so do all the rest of the lights

[badluckbravada]

my dad came up on friday and put in a new pvc or pcv or something and that didn't help so he tried changing the fuel filter but the bolt thing that actually screws onto the fuel pump the one with the "o" ring on it is rusted to the other piece of fuel line so hes trying to find a new one of those, so when he gets that hes gonna see if maybe that will work but idk...we'll see, any other ideas would be greatly appreciated

[ericn1300]

all the lights come on when you turn the key to start because its a test of the lamps.

a stuck EGR valve will cause a rough idle and stalling at stops and turn on the check engine light for a short duration, but would have no effect at high rpm unless maybe it was completly plugged. if you do take it off to check it replace the gasket with one that has a screen over the opening to catch any large pieces of carbon that can come loose.

the check engine light will go on and off intermintatly, usualy for smog equipment problems. even after the light goes off again the computer stores the failure code. take it the auto parts store, they will read the codes for free usualy. Chris has a list that tells what the codes means, so if you have a failure code and need to know what it is post it here.

[Chris Stewart]

Hey Eric, do you have a part number for that screened EGR valve gasket?
I guess it was just a matter of time until somebody incorporated a screen to the gasket. I drilled a dime sized aluminum disc with tiny holes and Jim of Phoenix found a stainless steel faucet screen worked for him...about 5 yrs. ago at the VMag Bravada site. It was a good site until an obscene poster ruined it for everybody and now it's deader'n-a-last-years-birds-nest but the archives are still open for retrieving info.

[ericn1300]

it was funny because the stuck EGR valve on mine cleared itself on the drive to the shop and i haven't had to remove it yet. we know it was the EGR from the failure codes. the service manager showed me one of the gaskets. I don't have the part number but it was a NAPA part. i suggest just ask for it, if they don't try to upsell you anyway.

[badluckbravada]

is it true that the egr valve costs $200 + to fix? and if so is that just for the part or like if u were to take it to a shop? is it hard to replace on ur own?

[Chris Stewart]

An EGR valve is easy to work on. It's held in place with 2 bolts and has an electrical connector. If you can change a tire, this is a piece of cake.
They're actually a pretty reliable piece except after running up the miles and carbon gets in it.
What happens is a little piece of carbon holds the plug valve in the EGR open and the computer finds out (pintle position sensor) and sets a trouble code. Removing the EGR, removing the offending piece of carbon, reinstalling the EGR and resetting the trouble code fixes it quick. Installing a screened gasket Eric described is the permanent fix for carbon lodging. Another thing that occurs is the stem on the plug valve will accumilate a little coating which will stick it closed or open. Removing the EGR and simply working the plug valve in and out unsticks the thing and after it works freely, reinstall the EGR. I haven't heard of anyone needing a new EGR...oh yeah, don't spray anything other than air in one unless you want to need a new one.

[ericn1300]

Originally Posted by badluckbravada

is it true that the egr valve costs $200 + to fix? and if so is that just for the part or like if u were to take it to a shop? is it hard to replace on ur own?

sounds like you found my old mechanic "250 Bob". How much to fix a fuel pump, Bob? $250. How much for new brakes, Bob. $250. How much if it's running rough and i drive by real slow past your shop while you listen, Bob? $250.

[Chris Stewart]

250 Bob...lol!!!

[badluckbravada]

soooo....so far we've replaced the fuel filter, spark plugs, pcv valve, cleaned out the egr valve(wasn't stuck so we blew some air through it to make sure there was nothing in there) and its still running like crap maybe even worse now, and..... the check engine light finally came on tonight. i have no idea what else it could be, is it possible that there is something wrong with the egr besides just that little plunger thingy? have u ever heard of a fuel pump going gradually instead of just all at once?

[badluckbravada]

we changed the plugs but not the wires, my dad said the wires look crappy but do u really think that just the wires will solve all of these shitty problems?