94 Ciera up and running but...

[Doc Salvage]

Finally got Mihoshi going again.  Been close to a year I think, she has been sitting there.

Running fine,  but since I did the LIM replace, she has been rough idling.  Will try to idle but then will finally sputter out.

Just put new WVE ignition module, and new NGK coils on, as well as a new WVE AIC.  

I'm thinking vacuum leak.      One unknown I am dealing with is the hose running from under the throttle body to the back valve cover opening.
Can I plug  this thing off?  I guess I need to get the wd40 out and start spraying around. 

Any thoughts on this issue?  Thanks in advance!

P.S. I'm off facebook, maybe for good...thing was taking over my brain   I am running a burner account so I can browse marketplace.

[Doc Salvage]

Took the Ciera out again today,  is fun to have her going again    Bit of history for this car,  we got it from mom in law with about 25k on it.  No probs for years until the inevitable sensor issues began showing up.   Fella down the road was parting out a Silhouette, so I got the wheels and the swaybar.  Couple of years later  the LIM goblin awoke and filled my crankcase with antifreeze.  (this is the L82 3100 SFI V6 btw) Had some wagon springs on the back for awhile but finally pulled em back out.  New struts up front, replaced tranny and engine mounts.  Now dealing with the idle issue.  Pulled the fuel pressure reg vacuum hose this morning with no change in revs,  interestingly, pulled the MAF plug and she would sit and idle in gear.     Might fire up my 30mm Avenger parts cannon and get a new MAF just to rule that out.   I'm afraid I've got a manifold leak.  Will update as I go through this,  I am a terrible troubleshooter, but hopefully will eventually iron the idle out.      Went through some curvies on the way home,  pretty amazing how flat she corners

[Doc Salvage]

Alrighty, found an extra MAF and swapped it. No change. Beginning to think I have an injector or two going bad. Will check fuel pressure at the rail sometime this week. Also planning on checking voltage on my IAC wires...odd to me that nothing happens (engine behavior wise) when I pull the plug on it. Puzzling evidence.

[Keith1976]

Hey man , start by engine cold does it do it or when it's hot . You can rule out if it's an open or closed loop by timing . Also if it's an injector she would be smelling like fuel and unstable idle and hear it in the exhaust tone . So many things can cause this . I'd check all vacuum lines especially the line to the transmission regulator . U can get one of those nipple plugs cheap at the part store to rule that out . Pull the line off the upper intake manifold it's by the pvc valve and cap it start up and see . Also there is a u tube video about gm fuel injectors by tapping them with a 3/8 extension and back edge of a screw driver to se rig the engine stumbles as carbon is built up . Being the Iac is giving you an issue could be carbon built up inside where it sits in the throttle body or the throttle plate having carbon build up as well . I find once a year the throttle body comes off and I clean it . So I would do things in small steps before throwing parts at it . If no check engine leak then simple things . About the open closed loop could be as simple as a coolant temp sensor or a o2 sensor out of specs causing it to run rich and having idle issues . Mx67627@aol.com sir as always send a email

[Doc Salvage]

Hey man , start by engine cold does it do it or when it's hot . You can rule out if it's an open or closed loop by timing . Also if it's an injector she would be smelling like fuel and unstable idle and hear it in the exhaust tone . So many things can cause this . I'd check all vacuum lines especially the line to the transmission regulator . U can get one of those nipple plugs cheap at the part store to rule that out . Pull the line off the upper  intake manifold it's by the pvc valve and cap it start up and see . Also there is a u tube video about gm fuel injectors by tapping them with a 3/8 extension and back edge of a screw driver to se rig the engine stumbles as carbon is built up . Being the Iac is giving you an issue could be carbon built up inside where it sits in the throttle body or the throttle plate having carbon build up as well . I find once a year the throttle body comes off and I clean it . So I would do things in small steps before throwing parts at it . If no check engine leak then simple things . About the open closed loop could be as simple as a coolant temp sensor or a o2 sensor out of specs causing it to run rich and having idle issues . Mx67627@aol.com sir as always send a email

Thank you Keith!  Did some troubleshooting  this morning after some cogitation over the last couple of days.  Pulled the EGR off,  resistance on solenoid A was 12.5,  B and C were both over 20,  which I'm not sure that was enough to cause a prob.  However,  hooked 9 volt battery up to terminal D on the valve,  A and C are clicking and opening but B is not.  Guide at easydiagnostics says REPLACE, so I am shooting for that as soon as I cut some grass and get some extra $$$    symptoms of failing egr line up with what I got.  May not be it, will update when I get it replaced.  Thanks for checking in,  hope your Century is still doing well!  oh I'll pop an email to you, thanks for sharing with me!

[Doc Salvage]

Alrighty, popped a new EGR in this morning, and she is idling smooth as glass    took a 75 mile celebration ride.  Now I gotta get back on some little stuff, like getting the glovebox to close. 

[Doc Salvage]

Newer (ish) pic...got to put her back to work toting boats

Also fyi,  EGR design changed in 96,  at least the top connector is different.