sounds like the fast idle cam to me. When mine was idling at 1500 or so I couldn't figure it out either. Apparently when I rebuilt the engine I somehow messed up the fast idle cam. I never touched the damned thing but somehow it got messed with. and you are positive that the throttle plaes are fully closing even with the throttle cable hooked up?

reread the thread, yes we took it out, and the plates are closed https://www.nopistons.com/forums/pub...1047683664.gif

lol I know, Its just I went through the same crap about a week ago. Gotta be a leak somewhere though....

yeah I took the uim back off, double checked all vaccume lines, double checked everything on the TB mod and its all good. made sure evrything was clamped with metal clamps, then adjusted the TPS a little. Got it all put back together and it held a solid idle at about 950-1k. After about 3 minutes of solid idle it started surging up and down from 1k-1500-1k-1500 ect. I think its got to be the TPS. I'm going to work with that a little more and see if I can't get it to hold a steady idle. I don't believe there could be a vaccume leak, I have checked everything over and tightened everything down over and over again.

you say tou did the throttle body mod, did you happen to polish the area under the throttle plates themselves? you may have a little air leak there. Also check to make sure your o-ring between the TB and the elbow is still there...

Also a quick thought, is your recirculation valve open to the atmosphere? the stock BOV. If it is, put your hand over it and see if you have vacuum pulling on your palm... they are not the best pieces of plastic...and commonly over looked when troubleshooting.

Hes got a blizt unit open vented. But the thing is the car was FINE before he dove in. https://www.nopistons.com/forums/pub...DIR#>/wink.png

Ok so Now the car is still surging. It starts up and holds a solid idol at about 1k, then after a few seconds it will drop to about 800 and jump up and down constantly from 800 to 1500. 1Revvin7 and myself have inspected all work done on the TB mod and everything looks good, I have clamped every single vaccume line and hose on the motor, and have went gunhoe with starter fluid and havn't been able to find any leaks. We also adjusted the TPS to spec today, and still no help. This is driving me crazy!!! https://www.nopistons.com/forums/pub...1047683358.gif https://www.nopistons.com/forums/pub...1047683358.gif https://www.nopistons.com/forums/pub...1047683358.gif https://www.nopistons.com/forums/pub...1047683358.gif https://www.nopistons.com/forums/pub...1047683358.gif https://www.nopistons.com/forums/pub...1047683358.gif https://www.nopistons.com/forums/pub...1047683358.gif https://www.nopistons.com/forums/pub...1047683358.gif

I kinda still have this problem. I KNOW it isn't a vac leak and i have isolated many electrical things. I know its got to be either tps or something electrical in the emissions system for me. Seeing as you have removed all emissions that narows it down quite a bit. Try unplugging the tps and see what happens. my idle drops about 300 rpm when I unplug mine and it just idles that much better. Try that and see what happens.

Well whats so strange is it idles steady for a different intervals, 5-25secs, then goes surging. I cannot figure this out. We need to decifer the codes the ecu is giving off.