94 blazer 4.3 v6 w lopes and stalls

[co.45]

I bought this truck two weeks ago it has a 114k on it and since then i've replaced the nut kit, FPR, a couple vac lines, clean screen for the EGR and ive pulled out the iac and it was clean already!

when it was sold to me the previous owner told me it was fine before the cap and plugs were put in. and it was obvious that whoever put it in either didnt know what they were doing or they didnt care att all becasue all the lines that were broke were in the way of eitherthe cap or the plugs.

and of course it hasnt been checked yet every time we try to it we found something else and didnt have time to check it.

ive also tested the vac lines by way of a unlit torch. i didnt find any leaks on the lines or the intake. i have yet to get a vac gauge waiting for payday.
i did find three lines running back to the transfer case two of the lines didnt have any suction? wasnt sure if there supossed to or not?

but thats it after all that it still does the same exact thing idle drops and then it goes back then it drops and stalls!

and im also under the assumption that since those vac lines were to that point it very possible that the previous owner never folloed the maintence schedule! and i probably have a couple of other sensors or wire that could have gone out?

any ideas would be great!

[co.45]

update i just hooked up the vac gauge i had 20 off the ball looking thingy and when i went to uplug the vac line coming off the back off the plenum it ran ok???

im assuming this is becasue i have a pinched line somewhere unless one of those line goes to my evap canister but i could have sworn the line off the front of the plenum under the thorttle went to the evap canister?? could it be one of the lines going back to the transfer case? and would that be causing the problem of it sputtering while driving at constant speed?


anyone have any ideas!!!???

[co.45]

Sounds like you have an idle speed problem since it idles better with a large scale vacuum leak. You may need a new IAC valve.

http://www.blazerforum.com/m_172755/.../tm.htm#173044


thanks guys you were a big help im glad i got some more input in the matter

[lesterl]

Might check the EGR solenoid, make sure it has vacume on one side and that a vacume source will pull the EGR open. Is this TBI?....... If it has the electronic EGR never mind.