Idle issue

7thousandpiecesMGTE

Boostin USA
Apr 9, 2007
469
0
0
Harford County, Maryland
Its a newly rebuilt 7mgte, 87 5 speed. Pretty well stock, just have a new 255lph fuel pump (stock FPR).

It Idled high when I got it back from Toyota, so i used the adjustment screw and got it down to where it should be 650rpm, but its rough here. Starts fine every time, idles around 1300 until it warms up, then it goes down to about 650 and surges slightly from 500 to 750, not horrible, but not right, and there seems to be a slight miss. Idle at 1000+ sounds much better.

No codes.

New plugs and plugwires installed by toyota.

Checked all vacuum lines everything is now hooked up correctly and no leaks(that I can tell). Egr modulator and valve all hooked up, no Charcoal canister (this line capped).

Car runs pretty good, boosts fine, and runs well overall. If I give a quick tap on the gas pedal when idling it stumbles and dies. WOT is fine, and a steady rev increase is fine also, again a slight miss if held steady.

CPS is making some bad noise, dont know if its the bushing inside or the old gear (not) meshing with the new cam gear, I have a replacement but i havent installed it yet. This is next on the to do list.

Could the cps cause this or should i look at other areas? IAC, ISCV? Looking for some help diagnosing this, done alot of searching and reading but not sure what to check next...

thanks for any input
 

dumbo

Supramania Contributor
Jul 16, 2008
1,911
0
0
Albera, Too Far North
What did Toyota do to you car?

Better yet, take it back to Toyota and get them to FIX THERE FUCK UP!
Shit I wouldn't of even popped the hood, I would of turned around.
But I'd never bring my car to the dealer...
 

7thousandpiecesMGTE

Boostin USA
Apr 9, 2007
469
0
0
Harford County, Maryland
dumbo;1227403 said:
What did Toyota do to you car?

Better yet, take it back to Toyota and get them to FIX THERE FUCK UP!
Shit I wouldn't of even popped the hood, I would of turned around.
But I'd never bring my car to the dealer...

Its a long story, but in the end the dealer put the car back together and then I drove back home 16 hours away. This car will never see another dealer as long as I hold the title.

So as much as I want to take it back it is not really an option, besides that I'd like to learn alot more about the car and the systems that keep it going too.

I have searched but all the idle threads I found had alot more problems than mine along with codes...
 
Oct 11, 2005
3,815
13
38
Thousand Oaks, CA
It is (slightly) possible that if the bearing the CPS is bad, then it will wobble enough to give a noisy signal to the ECU. Since you have a new one, swap it in and see if it helps.
 

7thousandpiecesMGTE

Boostin USA
Apr 9, 2007
469
0
0
Harford County, Maryland
UPDATE:

Ok finally got around to looking into this in more detail. I'm posting what i found for future searches (because it pisses me off to read through an entire thread thinking "this is exactly my problem only to have no last post with a resolution as to if they fixed it or how they did it....).

Ok got a new ISCV because I tested mine and it was bad. I learned not to F*%k with the idle "adjustment" screw as this should be turned all the way to the drivers side (closed).

Also replaced the CPS at the same time.

The miss is gone but i dont know for sure which one fixed it. Im guessing the iscv did it.


EDIT: Also cleaned up the throttle body, intake manifold inside and out, and check valve behind the ISCV (it was really gunked up, practically closed). If you have a similar problem check all of these things. Although Im thinking the cps is the least likely to have caused the slight miss I had, but who knows:dunno:
 
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shiftysupra

New Member
Nov 4, 2008
180
0
0
Tucson, AZ
had the same issue, mine would sometimes die if i went into nuetrel form driving on the freeway. so rpms around 3500 - 4000. also would hesitate on WOT around 3000 rpm all the way. and idle when warm (sometimes) would be at spec 650. i replaced the iscv and it solved the problem.