stalling 1997 tahoe

[gpsguy]

I have a 1997 4dr 4x4 tahoe, its has 182,000 on it. the truck has a hard time idling setting still, the trucks idle will go up and down the it will stall. i can start it back up and it will do the same thing over and over. when i drive down the road its fine put when i need to pass it falls on it face no power. when i come to a stop the car will just want to die.new plugs wires rotor wher just done , at that time I check the IAC sensor and its good ( 31 ohms) i even pull it out and cleaned it and inside , i also check the idle sensor and that was good (.5 volts close and 6. volts fully open).The questions i have is , I did a fuel press check last night on it, at key on it was 60 psi when its running its about 50 psi. when i turn off the truck I did a bleed down test and the psi went up to 60 psi. I let it set there for a 1/2 hour and it went down to 40 psi is that right? I have a brand new ac delco fuel pump to put in it if i have to and if i need to i can get a new spider set. i just was wndering if someone could give me some advise if i'm going in the right direction before i have my truck all over my garage .

thanks again

[j cAT]

Originally Posted by gpsguy

I have a 1997 4dr 4x4 tahoe, its has 182,000 on it. the truck has a hard time idling setting still, the trucks idle will go up and down the it will stall. i can start it back up and it will do the same thing over and over. when i drive down the road its fine put when i need to pass it falls on it face no power. when i come to a stop the car will just want to die.new plugs wires rotor wher just done , at that time I check the IAC sensor and its good ( 31 ohms) i even pull it out and cleaned it and inside , i also check the idle sensor and that was good (.5 volts close and 6. volts fully open).The questions i have is , I did a fuel press check last night on it, at key on it was 60 psi when its running its about 50 psi. when i turn off the truck I did a bleed down test and the psi went up to 60 psi. I let it set there for a 1/2 hour and it went down to 40 psi is that right? I have a brand new ac delco fuel pump to put in it if i have to and if i need to i can get a new spider set. i just was wndering if someone could give me some advise if i'm going in the right direction before i have my truck all over my garage .

thanks again

the fuel pressures look good. but i would replace the fuel filter anyway....

i would check vacuum lines and replace pcv as this can cause idle problems as well as the throttle body IAC being dirty and passageways plugged also the portion of IAC where it seats....

with a vacuum guage look /find any leaks...when you accelerate the vehicle bogs down this is a lean condition....too much air ,not enoungh fuel or both...........make sure MAF air ducting is secure no leaks etc....

[gpsguy]

Thanks for your reply, I have check the MAF a couple of times and all is good there.I didnt think about the PVC, but I will today. I did clean out the IAC and the passageway and let me tell you it was DIRTY, I did notice that when i did clean the IAC passage the truck ran good for a day or two. I will check for vacuum leaks today. a while back i did check the fuel filter it was clogged so i replace it, i did check it again the other day and it was good. thanks again

[j cAT]

Originally Posted by gpsguy

Thanks for your reply, I have check the MAF a couple of times and all is good there.I didnt think about the PVC, but I will today. I did clean out the IAC and the passageway and let me tell you it was DIRTY, I did notice that when i did clean the IAC passage the truck ran good for a day or two. I will check for vacuum leaks today. a while back i did check the fuel filter it was clogged so i replace it, i did check it again the other day and it was good. thanks again

if as you say after IAC passageways where cleaned and after this the engine ran good for a couple of days .... logic says clean again!!!!!

[rockwood84]

yeah could have pull some more deposits back in it[iac]