So I'm at a loss at what to do now and need to call upon the rotary experts to help out with their advice.

A couple of weeks back I removed my UIM and had it polished. I also bought a Rotary Works throttle body. After getting all the parts back, I reinstalled the UIM and new throttle body only to find when I started it up, the engine wanted to immediately rev up and go into full boost! I realized I had left the TPS unplugged and plugged it back in. That made no difference in the problem at all.

I then proceeded to troubleshoot the TPS and used the Power FC to set the voltages. After some adjusting, VTA1 read at 0.52v, while VTA2 read at 1.21 at closed throttle. Full throttle settings seemed within normal limits.

I then checked if my throttle cable was too tight, but it seems okay to me. I checked operation of the cable while depressing the gas pedal and it didn't seem to be abnormal to me. The last time I had the elbow off, the operation of the butterfly seemed okay to me as well, and wasn't sticking.

So why is does my car immediately go into full boost/throttle right after starting it up? Needless to say, I'm kind of antsy to let it do so right after starting cold and usually shut it off. Which then leads me to having to deflood it.

It should be noted that the Rotary Works TB eliminated the AWS and I believe fast idle cam? The TB only has the throttle and TPS on it.

What say you?

 

AWS runs off the UIM, and feeds to the OEM elbow. You should be able to adjust the TPS such that VTA1 and 2 are right in the middle of their spec----- 0.40 and 1.00.

Definitely posts pics of your setup to help us troubleshoot...... have you tried to start the car with the elbow off to see what the TB butterflies are doing?

Also, what else was deleted off your UIM? Is your ISC plugged in (white connector on middle back of UIM)? If so, try unplugging it and manually adjusting your idle.

 

Here are some pics of my setup:












I had to lengthen the wires for the TPS since the original wiring didn't reach because of the increased length of the RW TB. I have started it with the elbow off but it basically acted the same. As for what's not on the UIM, double throttle was eliminated, as is fast idle cam.

I've seen a video on YouTube with a RW throttle body seemingly running with just the throttle assembly and TPS and it appeared to idle fine. ISC was disconnected but I reconnected it.

Let me know if any additional pics are needed. Thanks!

 

How much slack does your throttle cable have?


Those RW throttle bodies are nothing but problems...

 

looks like your idle screw is all the way in. Might want to start there.

 

Ok, this you might find interesting. That screw is all the way in because that's about how far the throttle sits back when closed. If I screwed it further out, the throttle would still sit at the same place. I've adjusted the throttle cable nuts to give more slack, but it doesnt really add any more so that reaches further down if the screw is around middle. Does that screw even control anything on this TB other than act as a resting pedestal for the throttle?

 

Take pics with the elbow off so we can see the throttle plate first off.

It looks like you are running the idle valve so that screw on the TB to adjust the plate should be all the way out. I suggest disconnecting the throttle cable and setting the plate that way. Then hook the cable back up, the plate shouldn't move. That throttle cable looks way too tight, there should be visible slack on it.

 

Thanks, I'll take pics and try out your suggestions as soon as I can get off work. Nothing like having a case of the Mondays on the Tuesday after a long July 4th weekend!

 

If you disconnect the throttle cable and start it and it still revs up like crazy, I would look for a seriously bad vacuum leak. I thought those throttle bodies had a history of leaking? I could be mistaken though.

Matt

 

Make sure the vac line that connects to the brake booster is connected and not leaking.

 

Would a vacuum leak cause the engine to want to rev to redline though? Wouldn't that be a massive leak? I'm seriously asking, I don't know?

 

Mps_hell
looks like your idle screw is all the way in. Might want to start there.

Did you understand this?

It looks like the throttle stop screw (which is used for idle speed on this POS throttle body) is all the way out keeping your throttle plate open...

 

Yes sir, I did. I'll try that out as well as messing with my throttle cable again when I can get to the car again.

I appreciate everyone's help in this. Thanks guys!

 

Yep..your throttle cable isn't long enough. you will have to change how far away it anchors from the throttle body, then you can fine tune idle with that stop.

My recommendation...put the stock throttle body back on :]

 

I'm starting to agree that my throttle cable simply isn't long enough. When I try to connect the cable with the throttle plate it opens it up a small bit. That's enough to make the idle shoot all the way up. If I start the car with the cable disconnected and the plate fully closed, the idle stays down.

Cable disconnected, plate closed


Cable connected, plate slightly open


I adjusted the screw all the way out but that doesn't really change anything since even with the cable disconnected and plate fully closed, the throttle lever never comes close to where the bolt sticks up.


I tried unscrewing the bolts next to the UIM and TB to give the cable more slack, but it's simply not enough. As it stands now, I can barely get the cable to fit with the TB plate closed but only if I disconnect the cable out of the holder next to the UIM. And even then the idle is crappy and eventually dies, although that might be because TPS is out of whack after I tried troubleshooting.

I'm going to try again tomorrow, but if I can't figure it out I might just put the oem TB back on. It looks nice but I'd rather drive my car than just look at it.

 

It is just the distance from where the throttle bracket that anchors the cable to the throttle body pulley that matters.

You should be able to bend the stock stamped steel throttle bracket forward the throttle body to "make the cable longer".

But going back to stock is not a bad idea at all. I have never heard a good word said about that Rotary Works throttle body.

 

I actually had the Rotary Works TB and I liked it. It seemed like the car reved faster. I imagine it was just the one spring on the RW tb that was weaker than multiple springs on the stocker.

But with my setup I couldn't get it idle quite right. I have no idle valves etc with my setup. It would only idle smoothly above 1100 unfortunately, it bugged me enough to swap back to stock.

You should be able to bend the bracket for the cable to add slack or fab something up pretty easily. I say, give the throttle body a chance.

 

I've seen a friend put one of these RW throttlebodies on a car here near me. The stock throttle cable is too short to accommodate the extra length of the RW body, and this strains the cable out too far. We ran the car on a local dyno and there was no measurable HP improvement with that throttle body, and it refused to idle properly unless a new cable was made.

I think he used the words "expensive shiny paperweight" as he sold it and put the stocker back on.

Even the stock TB setup requires a little bit of cable slack to idle and operate properly. If you completely adjust the slack out via the adjustment nuts on the stock cable, it won't idle and will hunt/idle fast. If you get your finger on a good stock car and push down on the bare cable where it connects to the throttlebody, there should be 1/4" or so of free cable deflection slack. Taking that out will cause issues.

 

I gave it the ol college try, but in the end I think I am calling it on the Rotary Works TB for now. Even after putting in a spacer to give the cable more slack so that the plate is closed all the way and adjusting TPS, now I have another problem. The car idles weird and has a hesitation when I apply a small blip of throttle. Maybe I have to get the Power FC to relearn the idle?

At this point, between having a nice shiny throttle body and a working one, I'd rather have a plain working one. Now I need to buy a new cable since mine looks like ****.

A big thanks to everyone that chimed in. This community rocks! Feel free to continue the discussion though...

 

For the one millionth time....

The RW throttle body is a piece of garbage.
*it is known to seal poorly and cause high unstable idle
*the one throttle design doesn't mate with the stock UIM
*the cnc port job is hilariously bad

It's an easy way to spot a rookie/idiot FD owner.

Stock stuff works
Either get BDC to knife and port your stock TB.
Or
Pick from a short list of legit companies charging a fair price to put bigger blades in the stock TB(RC engineering?)

 

I used these guys years ago, no real complaints..

RotorSports Racing Extrude Hone

 

Excellent, thank you. Rotorsports did good work for me too, on a previous rebuild.