Idles ROUGH

[knightrider]

I have a new to me 2.5 auto 4x4 200,000+ miles with new cap rotor, plugs, wires, alt oil change and such.

Truck is idling rough as hell, but smooths out once above idle.....any clues?

I'm sure the O2 sensor is original. Any other places to look?

[mjtjnj]

Is the IAC motor working? That would be the first thing to check. If it does extend when you turn the key, turn the bolt in it out a few turns, to turn up the idle speed. I don't suppose you have a tach on the vehicle?

[knightrider]

Correct, no tach. As for extending, I will check, and adjust it, if it doesnt, I'll buy a new one.

[Pete M]

While you're in there, try cleaning out the throttle body with a throttle body cleaner (meaning that it's o2-safe) and a toothbrush.

[attaboybob]

maybe you moved the Distributer and knocked the timing out.

Or, maybe you have a vaccuum hose loose or cracked.

 

BOB

[knightrider]

I do have a vacuum leak I haven't been able to find yet....could be the culpret. As for the timing, I can't adjust it in any way....it's fixed.

[FxRacing282]

possible vacume leak could be on the brake booster. spray starting fluid around the "conections" for vacume lines and when themotor runs a little better or worse then there is the problem

[knightrider]

After replacing all but the elbow style vacuum lines (gonna buy from dealer) I realized.....the MAP sensor wasn't even hooked up. The line 'appeared' to be hooked up but once I touched it it moved due to just old cruddy dried out hoses.

 

I went through most of the other vacuum driven parts on the truck to make sure they were in decent shape for the upcoming winter.

 

As for the truck.....idles smooth as glass......need to adjust the idle stop solenoid (sole-vac) and should be good.

 

Can't believe it's been running at all. Now it's happy as can be and idles, sounds good.

 

Anyone have any 2.5 (h) code vacuum line hose part numbers for the manifold and hoses on the back (firewall) side of the engine?

 

Thanks again for the help!