vrracing

iTrader: (1)

JDM S5 Tii

We're doing a baseline adjustment of the TB as part of our diagnostics for why the car idles at 500 and wont rev without stumbling. In the FSM it starts on F2-35.

The FSM states the the fast idle (I think yall commonly refer to it as a cold idle) when at 77 degrees should be adjusted so that the upper tick mark should be aligned with the upper tick mark highlighted in red below to the cam roller highlighted in green. It's not even close on ours.



I just wanted to confirm with yall that it is the red mark and not the black mark that we align with at 77 degrees.

We did use a blow dryer on the fast idle device and it did pop up so the thermowax works.

Do yall put any grease on all these sliding parts? Seems like they'd be prone to binding.

Thanks

HAILERS

Once the thermowax roller leave the cam...................it has no part in idle anymore. So that probably isn't your five hundred idle problem. The fast idle screw/cam are only related to a cold engine, not a fully warmed up engine.

IS your five hundred idle with the initial set coupler in place? or? not. If it five hundred without the initial set coupler in place, fully hot engine, then I'd suggest you have two problems. ONe would be a non functional BAC and the other the need for adjusting the rpm to five hundred with the initial set coupler in place.

Pull the BAC off if your not getting any input from the BAC screw. See if the BAC gasket isn't covering the small hole that feeds air from the BAC screw. Blocking the path is what I mean.

vrracing

iTrader: (1)

Yes, I know. I have to figure it is something stupid so I'm going methodically over everything.

It won't rev either, it just stumbles and bumbles. So the BAC wasn't on the top of my list. I'm starting at the LIM (isolated pressure test is next), then working up I'll go thru the ACV, then BAC.

We pressurized the system again and found the air leak at the front butterfly shaft covered by the fast idle device. So we replaced the gasket on the fast idle with a homemade one without the slot and then it idled at 500 and on rev'ing bumbled and stumbled and dumped smoke like crazy it was so rich. So now we've cut the slot back in.

I've already rebuilt the fuel injection system (professionally cleaned injectors, all new rubbers, swapped out the fuel rails) and replaced the fuel pump with Walbro. Before I put the UIM back on I'm going to do yet another round of fuel pressure tests and then I'll do the tests with the injectors pulled and wired to the rails.

I also did the vacuum test on the boost sensor. It read the 2v at the 100 vacuum.

Like I said, it's something stupid. Once we got the first problem solved the car ran beautifully for maybe 15 minutes. Then suddenly it went back to surging and wouldnt accelerate.

It's driving me nuts.

HAILERS

Series five. Have you checked for any fault codes? Like MOP? or AFM being bad.

Also, do you have the ability to get a meter out, full get the engine HOT and while at idle, check the narrow range and full range TPS inputs to the ECU? Narrow range should read approx one volt dc idling and a hot engine.

The RED line should be over the roller at 77*. You may fudge a bit one way or the other so the roller will fall off the roll pin earlier or later. Whatever you fancy. Falls off sooner........fast idle stops sooner.

And does this throttle body have the THROTTLE BODY mod where they rip out the outer set of secondary throttle plates?

vrracing

iTrader: (1)

JDM S5 Tii

We have the normal codes for a JDM Tii swap into an NA. But the MOP is ok. The NA's AFM had a big ohm spike right as it started to move so I put in the 370 AFM. I haven't tested it yet but will.

The TPS was accurate before. I'm going to do the ohm tests again and then we'll do the LED test again (already have done it a dozen times).

The throttle body appears to be stock. It's here on the counter and there are two butterflies at the front on the bottom and then there are three butterflies on the back.

HAILERS

Was the engine fully HOT when you did the LED setting of the TPS?

My personal preference is to look at the output of the TPS with the engine idling fully HOT. Should match the FSM, CONTROL UNIT page for the narrow range TPS. As in being one volt dc at idle fully hot engine.

Primary injectors not mixed up with secondary injectors? I mean the elect plugs on the wrong injectors.

Bad stummble when taking off sounds somewhat like a afm problem or TPS with a faulty pot. It's too hard to say not being there. YouTube sounds don't do much for me either.

vrracing

iTrader: (1)

Ha! Yeah, YouTube does terrible things to sound.

No, it wasn't fully hot when we set it. It was 100 out though. It was running well when it suddenly went bad while we were driving it. Maybe it got hot and went out of adjustment. But you'd think it would be good when started up cold. We'll redo it when we get it all back together. Get it hot and reset the tps.

I dont think the injector wires are mixed up. The primaries are very short and the secondaries very long. I did make sure the brown taped ones are on the front rotor.

I did the ohm tests on the NA's AFM but didnt when I put the 370 AFM I had gotten for the swap.

Thanks for the help, HAILERS.

immanuel__7

iTrader: (8)

any new updates on your prob, cause im having the same dang thing, i cant rev mine ok, but if there's a load after hitting boost once then il will do the same thing yours is doing, and some times i cant hit 5 psi in 3 or 4 gears then it will start to stumble. im starting to think its the map sensor that's messing with me as i was missing a TPS and it was stumbling after i installed the tps it started being worst where i can barely hit boost at all im lucky if i can hit boost once. but if i take off the tps il get boost at least once, and if i shift fast enough and keep the boost up it get 3 gears of out if then i have to shut off the car and back on to get an other chance at boost...

thanks for your help in advance as wel.

vrracing

iTrader: (1)

No updates. I tore apart the ACV but we had family in town so didnt make any progress. And now I'm at my son's college freshman orientation so probably won't get to it until next week.

immanuel__7

iTrader: (8)

im trying some today il let you know how i make out, the FC engine is installed in my FB, so i did not know i needed to have a pill installed before the map sensor (pill "restricts/stops of boost surges to the map making it hit fuel cutoff and making it change its timing all funkey)
il keep you posted

immanuel__7

iTrader: (8)

well i did try the pill trick and still the same thing, i did use a 0.055" hole i seen some ware that a 0.02" might work so il that that this sunday, an other thing im seeing is that my timing is jumping allover the dang place, its so odd