JimMueller

iTrader: (9)

TB is a BlueMaxx and the blade already has a ~7/64" hole. Car is tuned OLSD. I've worked on the VE some, and worked on the RAF a bit. Part throttle in 5th and 6th gear really woke up on the trip back from Vengeance, who did the install. I didn't arrive until 4:30PM and they had it swapped in an hour. Throttle pedal is really sensitive and/or stiffer compared to the previous truck TB.

Some notes I took briefly:

- Throttle voltage range engine off: 0.82V to 4.84V (measured from the scanner, not a DMM)
- tps engine off: 1%
- IAC Position engine off: 143
- throttle voltage engine idling: low is .71V
- IAC position after letting engine warm up to 176*F: 34
- blipping throttle at idle causes tps to drop to zero upon return, jump to 2% as after it overshoots, then drops back to 1%

On my trip back, after I was having some idling issues in the gas station parking lot, I saw the IAC Position was in the teens. Can someone go over what I need to insure is set right phyiscally... TPS voltage, all tables which may need to be adjusted, etc? Right now I still have the original Whisper lid and stock MAF and bellows. I know that's not ideal, but that's how it is at the moment. I'll get a 85mm lid and bellows soon.

Thanks!

DrkPhx

iTrader: (15)

It sounds like you just need some basic idle airflow adjustments and probably open up the TB blade a little as well. The TPS should read 0.0% or no more than 0.4% at idle and engine off, otherwise the PCM might not be using the idle airflow tables which could cause the hunting problem. First, try and reset the TPS to get it lower. Then work on the idle airflow tables.

Ron@Vengeance

iTrader: (51)

Thanx for making the trip all the way up!!! Hope you enjoy your mods and have a Merry Christmas

JimMueller

iTrader: (9)

Ron: I'm sorry I missed you. I didn't get your last e-mail until late Monday and I didn't find out you were out yesterday until I was enroute. I'm just glad Mike and the guys we're still there when I arrived!

DrkPhx: The IAC position is already too low indicating I already have too much air coming in. Why would I want to add more air and decrease the effectiveness of the IAC motor?

tblu92: I'll try that tip.

DrkPhx

iTrader: (15)

That's not necessarily true all of the time. IAC steps are not an actual measurement of incoming air, but how much the IAC pintle is open or closed in steps. The IAC can be maxed out open and the engine may still need more air because the the TB blade may not be open enough forcing the IAC to try and compensate by opening all of the way.

My point was to get the TB set screw set correctly so the TPS was indeed 0% at idle and so the IAC can have the full range of adjustments from closed to open. My experience with the 90mm TB is they almost always require some adjusting of the TB set screw to help get the idle airflow in line. I know every car is different, so this a basic guideline.

JimMueller

iTrader: (9)

I adjusted the set screw, and now it always shows 0% with my foot off the pedal. I also noticed a nut laying loose behind the PCV tube on the intake, found that it had come off the bolt directly above it. So I put that back on and checked all the other allen bolts I could find. A couple weren't what I would call snug so I turned them less than a 1/4 turn to snug them. I also found that the black 90* orifice tube on the TB which connects to the passenger valve cover was barely tight. I was able to turn it a good 3-4+ turns until it was snug.

So the IAC position seems to be better just while idling, time will tell. I need to adjust the RAF again as it wanted at least another gps of air, and it was within .5gps STIT before.

Next question... TPS voltage now ranges from .76V to 4.84V. I've read that that there can be problems if the upper range exceeds ~4.7V. I don't see a method to stop the cam earlier so it doesn't go so high, and I've also read about issues if the lower voltage is not between .4-.6v. Is this where I need to perform the tps reset? I'm not terribly excited about drilling on the TB to slot th eholes, etc.

JonCR96Z

iTrader: (33)

You can adjust the TPS' position to make it read what it needs to.

JimMueller

iTrader: (9)

I hadn't gotten around to following up, but I ended up slotting the screw holes in the sensor, now the range is .49-4.71V. Reset the TPS so it's 0% at the new closed position. Hopefully that's close enough.

DrkPhx

iTrader: (15)

Did the idle stabilize? If not, you can increase the values in the Desired Airflow Table to see if that helps.

Correct. Mine seems to work fine at .4 %.

1bad lad

u need to have the tps at close to .5v at idle. if ur sayin that the tps was at .74 and the iac was in the teens then this tells me the computer is tryin to cut off some air. close the throttle blade i little bit so the tps is down to .5 then u will also see your iac come back up. should around 30-50 counts. after u accomplish that then adjust your idle airflow tables.

JimMueller

iTrader: (9)

DrkPhx: Idle really hasn't stabilized, but I haven't had time to mess with the RAF much since addressing the mechanical issues. I've never understood the throttle follower/cracker tables, how to adjust them and by how much.

1bad lad: TPS was in the mid .70's, after elongating the bolt holes on the sensor, now it's at .49-.51 at idle and 4.71 at WOT. Although I haven't logged due to my laptop battery dying, the new IAC position seemed to be in the 60's at warm idle.

It feels noticeably stronger in 1st, 5th and 6th gear, without any knock. 3rd and 4th are getting audible knock at WOT but not much showing on the scanner. 2nd doesn't seem to be getting any audible knock but for some reason it doesn't seem to be real strong yet. That'll be next on the checklist after I resolve the whole idle issue.

1bad lad

well thats good ur tps is down to .5ish. yea u need the iac to be on the low side of 30-50ish. this will allow for more correction if it tries to stumble or stall. if the iac is already at lets say 100 and the car is idling but then stumbles then it has lesser amount it can open to try to save it. some people don't know how to correctly set up idling controls. they just automatically assume they need bigger holes in the throttle blade. well then they end up with the ecu tryin to close the iac completely then opening it and closing it. then the car ends up hunting for idle. ***** anoying. gatta get the iac and the blade in the right spot then adjust idle airflow tables

Gh0st

iTrader: (3)

Sounds like my experience.

The TB is a pile of ****. I've had one replaced and it's still getting stuck all of the time. Very annoying to drive. Only way i can get it to feel good is to make the throttle cable very tight which isn't what you want.

My intake bolts were also loose and the throttle body bolts were completely backed out by the time I got home. I tightened all of the bolts per specifications and they haven't backed out since.

JimMueller

iTrader: (9)

What are the tightening specifications for the bolts? Same as OEM? The blade seems to only have begun sticking once the cable slid off the cam guide, the end of the cable was still in the hole. I'll have to admit I don't like the throttle cable so tight because it brings the throttle pedal up to the same height as the brake pedal, and it makes it easier to press both simultaneously. I think I'll call Ron tomorrow to see what my options are. This should have been one of the later model BlueMaxx's which had the previous sticking problem resolved.

Gh0st

iTrader: (3)

Intake manifold is 7 INCH pounds and for the TB itself, not sure, I tightened it "good and tight". I have not had a problem with the bolts since then, it's been a while. Ron suggested I apply loctite to the bolts too to help prevent vibration backing the bolts out again.

If you're having issues I'm sure Ron will swap the TB for you as he did for me.

JimMueller

iTrader: (9)

I spoke with Ron and he offered to send a replacement but for now I'll try to slightly sand the interference spot(s) on the housing to cure the sticking blade.

Gh0st

iTrader: (3)

That's a good idea, I may have to do that. Does your TB whistle at all during startup?

JimMueller

iTrader: (9)

Hmm, can't say I've noticed it whistling... you're talking with everything installed, right (baffle, lid, etc)?

Gh0st

iTrader: (3)

Yeah, I've got an open element filter so I hear it, it's just the IAC passage. I keep forgetting the F-bodies have a closed intake.

JimMueller

iTrader: (9)

I sanded the bore and it's no longer sticking