I am starting to experience an idle issue where sometimes the car idles @ 550 as it should. Other times @ 750, and still others @ 1000. Once the idle comes up to say..1000 rpm it will always idle there until I shut the car off and restart it and let it idle in park for a sec. until it comes down to the correct idle (550). Sometimes it idles just fine and others it will idle high..nothing in perticular sets it off. I'm thinking worn shafts in the throttle body (70,000 mile motor)and I'm looking to see if anyone has a place in the great lakes area that rebuilds them. I've not heard alot of good things about the aftermarket stuff (bbk, holley etc) so I'm not really looking to go that route. Thanks in advance.

 

Naw. Its kinda hard to wear one out esp at the low mileage one you have. I would look into cleaning it all out and adjusting the iac

 

Sorry should have given more info. Bought the car last year. Had a fluctuating idle. Intake leak. Went through the top end... New cap, rotor, wires,plugs, egr valve, intake gasket set (upper and lower) injectors, checked iac and tps (all well within spec) 02 sensor, ecm ( origional failed) maf burn off and power relays, fuel filters and set timing. I bead blasted the lower intake, runners and plenum and cleaned the TB. The car runs strong but this idle started this spring and has gradually gotten worse over the summer. I do get a little play in the throttle shafts (but if I spray intake cleaner the idle doesn't change) but not much. I also have the typical leaking valve seal blues but I'm going to freshen the bottom end and install the sdpc vortec head kit over the winter. I'm wondering if I'm poisoning the 02 but I wouldn't think that would effect idle quality and I'm not getting a code. I just want to correct this now so when I redo the motor this winter I now all is working ok.

 

You said the original ECM was fried. Did you ever find out why? Typically, it's something such as a solenoid/injector which is out of spec that causes the ECM to fry. I'd recommend placing a meter across a few select terminals and making certain they're all good. Specifically, check the injectors and mnore if you feel like it.

 

Thats exactly what caused it. Hence the new 'puter and injectors. Once the fuel delivery issues were corrected the car ran really well. Since late spring of this year the idle problem has persisted and its gradually gotten more severe as the summer has gone on.What are most people on the boards running for a TB? Are you happy with it. I don't really need a 52mm TB as my plans for the motor are the vortec head kit with a custom chip. I plan on retaining the stock cam for drivability and fuel economy. This ain't no race car and I'm not looking to turn it into one, but I think I'm reasonable in hoping for 3-310hp and 25 MPG. I just want it to idle properly. I'm wondering why, when it starts to idle high, if I shut off the car and restart it, and let it idle for 20 seconds it will resume idling at 550RPM. Strange.