High idle and cutting out @ idle

[CanMan]

Quick recap: Reciently replaced my stock intake manifold and TB with a non EGR intake manifold and a 1G throttle body. FIAV has been blocked off as well, with JB weld. Rebuilt the TB with MIL.SPEC seals, new OEM FIAV gasket, new OEM TB gaskets, new ISC o-ring. Replaced the intake manifold gasket with an OEM one as well. New BISS o-ring. The manifold has been ported to match the intake gasket. Also replaced the plugs with NGK BRP7ES. Nothing else major was changed except for the TB and intake manifold.

I have done a BLT with good results, no leaks. Ive set the TPS at 0 ohms with a .0175(closest I could get with the feeler gauges I have) shim under the throttle stop. I have also tested the ISC for resistance at the coils, and there is only a difference of .3 between them. The MDP is gone(no boss for it on the intake manifold). I have also swapped out the MAF for a known good one and seemed to help some until I took it on a test drive and the idle went back up. Have checked the pins to see if any were bent/depressed but look good. BISS is screwed in all the way, any unscrewing of it will make the idle higher.

Idle starts off around 1150 RPM's and slowlly climbs to around 1400-1500 as engine temperature rises. When I swapped the MAF, idle went down to 950ish, but kept cutting out momentarly for a split second and would drop to around 800, stumble, then right back up to 1150 or so, then come back down to around 950 and run crappy.

Only code I'm getting is a P0141 for the rear O2 sensor(its been on for 9 months). No MDP code, no MAF code, no other codes. Battery has been out so codes have been cleared, but decent mileage(25 or so) have been put on the car since the battery was out.

At this point I'm stumped on what it could be(without taking it to a shop). Knock sensor? Crank/Cam sensors take a $h!t when they got unplugged?

Car is stock other than what is listed in my profile. Any help would be greatly appreciated!

 

[Tooltrt87]

I would just try an idle air conroll valve. The mass air sensor changing the idle would seam to rule that out though.... Try third mass air and see which one of the others it has the closest relation too.

 

[CanMan]

This is my DD, and I'm not one to keep throwing parts on something in hopes to fix it, especially when there isn't much available locally in junkyards or from other DSMers.

I doubt 2 different MAFs would cause the same problems. Going to put the 2G TB back on and see if that helps. I did notice that the TB butterfly had the ever so slightest gap all the way around the TB bore when I finished rebuilding it. Might as well rule out that possibility.

 

[Tooltrt87]

Any results on changing the tb?

 

[CanMan]

Decided to throw an ISC at it after testing everything else possible. Fixed the problem. Guess you can't always trust an ohm test. Even with the ISC removed and turning the key on, it moved in and out, but if you did it over and over(roughly 5-8 times), it would hardly move. Suspected that 17 years of use took it's toll and just became weak. Kinda weird it only acted up after doing nothing but moving it from one TB to the other.