Mechanic Help!!!

[krisw]

Does it sound like it’s revving at 2500 rpm, or is the tach showing that? Could be a loose connection or something like that for the tach.

[Goldeneagle]

Does it sound like it’s revving at 2500 rpm, or is the tach showing that? Could be a loose connection or something like that for the tach.

Could be this. Is it actually running 2500rpm or just what the tach is showing? I have a '93 1500 and my gauges are starting to do goofy things. I need to remove the cluster and check the wiring on it.

[IAFFHunter18]

Oh no it definately is reving at that. But I can go to D,R,3,2,1 and it idles down. P or N is revs back up.

[6.5 shooter]

Check the o-ring where the brake booster locks on to the manifold.

[540 MM]

Yes, has the spider injector set up however it is poss to pull injectors up out of port and install in incorrect location. Have seen this a bunch of times from local shops incl dealerships causing erratic idle, random misfire faults etc. Since you left them alone, ck oring around injector pass thru connection. Make sure no debris made it down throttle body affecting blade travel. How did you stab distributor?? Remember dist is only for cam reference with that being said you must set initial dist location with scan tool. You have to initiate it and set it. Even if u marked dist before you removed u must set it with scan tool! Cam retard will make idle stick due to base idle timing fail!

[540 MM]

How did u adjust valves? Why did u replace heads? Where did u get heads? What are ur head and intake gasket part numbers? Just trying to help

[IAFFHunter18]

Ok ill do my best at answering...... distributer was marked and reinstalled by a a mechanic buddy who also set the timing with his scan tool. I had a bad intake gasket leak on the ds and the ps head had several cracks. So I replaced both of them with new heads and complete new gasket set. Not sure on model number on the gaskets but after it was all done and the idle did what it did and we checked everything else, i figured crap maybe we got something off or not set right so we went all the way back down a second time replacing the gaskets again and still no change. The heads, valve springs, all the hardware was replaced with new parts and adjusted by a well known and respected local motor guy. What I dont understand is that running it sounds really good, smooth, no ticking, no missing, etc. just idles high in park. Im lost.......

[krisw]

My 97 z71 will idle kinda high in park sometimes. Usually around 1000 rpm or so. But only when I first crank it and it’s cold.

[IAFFHunter18]

Ok changed changed/checked all vacuumm lines and orings. Still cranks up and runs very smooth. Just idles at 2500 rpms. I dont get it. Just left it with a mechanic that has a computer.

[mastercraftka]

Isn't there an idle sensor on that year model? So when it is cold it revs up and then after it warms up it goes back down?

[IAFFHunter18]

Isn't there an idle sensor on that year model? So when it is cold it revs up and then after it warms up it goes back down?

Im not sure. If your talking about the Idle Air Control sensor then I have replaced that one with know change. Unless I am missing something which is highly possible, everything else I have found has to be adjusted electronically.

[BIGTERRY75]

From a mechanic....................

















Take it to a mechanic.

[kurt68]

Could you have bent the control arm on the throttle body? I know i was doing work on my old truck and it was idling high, I bent the bracket barely that the throttle cable rested against with the adjusting screw. Might check that or if it has that kind of set up.

[kingranch]

u sure throttle body butterfly isnt getting stuck slightly open? I could see this happening and the load when in gear is enough to keep the engine loaded down a bit-
try wiping the inside of the tb out with rag that was soaked in tb cleaner esp around the contact points

[540 MM]

Need more info; short term fuel trim correction, IAC counts, minimum TPS voltage, desired idle with actual idle rpm that ECM is seeing or commanding, O2 voltages and swings, etc. To properly diagnose a prob u need proper tools. JMO.