Infiniti Q45 Throttle Body [Merged 4-8]

[SilverJester]

first off, I am posting in this forum because this is where I found part of my answer...but please move if it's in the wrong place.


I have a 2g which means I have 4 wires going to the TPS. the q45 tps has one pig tail w/ 3 wires and a short harnes w/ 3 wires. So far what I've been able to find is the the short harness is for the actual TPS and the pigtail is for the "idle validation circuit". I'm not sure what that means but I found it on some supra forums. I know that the difference between the 1g and 2g tps is that the the 4th wire (which ells the ecu if the throttle is closed) is seperate on a 1g. Could this be the same thing as "idle validation"?

So far this is the info I have come across as far as wired and what they are for:

q45 tps harness (not the pigtail):
-Red is the 5 volt input wire
-White is the TPS signal wire
-Black is the sensor return wire

2g tps harness:
1 - Green/Yellow (+5v Sensor Power)
2 - Brown/Red (TPS output voltage)
3 - Yellow/Red (IPS switch)
4 - Black (Ground)

Ok so I'm still a little confused on what wires to connect so if anyone has experience or more info t add I would appreciate it.

 

[GVR4592]

It seems pretty self explanatory to me. Just leave out the idle position wire on the g2 connector and everything else is pretty basic. If you know which connector is for the tps on the Q45 TB, just hook up 5v power, signal, and ground.

 

[97gstnick]

but with the idle switch not connected, will this throw any CEL after a while? how about an erratic idle? does base timing get screwed up with the idle switch not connected? why is the idle switch there? what purpose does it serve?

i am in the same boat as i have a q45 yet to be installed.

 

[pneumo]

but with the idle switch not connected, will this throw any CEL after a while?

Most likely, the 2G seems to throw a CEL if the wind blows from the wrong direction.

how about an erratic idle? does base timing get screwed up with the idle switch not connected? why is the idle switch there? what purpose does it serve?

The idle switch is there so the ecu knows when the throttle is closed. It's used to shut off all fuel when the throttle is closed AND engine rpm is above 1200. So without the IPS hooked up your car might sputter when decellerating. It shouldn't have any effect on timing.

I'm in the same boat as you guys, I just got a Q45 TB for my new setup. I probed the wires with an ohmmeter while moving the butterfly and found the thicker red and black wires seem to go from infinite resistance to zero resistance as the throttle opens past about 30%. That's not quite the same as our IPS. I got nothing out of the green wire.

Since I have a 1G I was thinking about mounting the stock IPS switch on the TB somewhere else. Maybe this would also work on a 2G? How do you 2G guys wire up a 1G TB? If you could use the 1G IPS this would solve the problem.

 

[97gstnick]

Most likely, the 2G seems to throw a CEL if the wind blows from the wrong direction.
The idle switch is there so the ecu knows when the throttle is closed. It's used to shut off all fuel when the throttle is closed AND engine rpm is above 1200. So without the IPS hooked up your car might sputter when decellerating. It shouldn't have any effect on timing.

I'm in the same boat as you guys, I just got a Q45 TB for my new setup. I probed the wires with an ohmmeter while moving the butterfly and found the thicker red and black wires seem to go from infinite resistance to zero resistance as the throttle opens past about 30%. That's not quite the same as our IPS. I got nothing out of the green wire.

Since I have a 1G I was thinking about mounting the stock IPS switch on the TB somewhere else. Maybe this would also work on a 2G? How do you 2G guys wire up a 1G TB? If you could use the 1G IPS this would solve the problem.

ahhh, thanks for the enlightenment.

maybe somehow we could mount the stock TPS like you said.... hmmm. im going to have to experiment. i have some sheet metal laying around, i'll let you know if i come up with something good.

 

[GVR4592]

Ok you guys have Dsmlink right? You don't need the idle switch, you can simulate it with the Dsmlink software, you can also offset the TPS to help get the idle correct. Go to the Dsmlink forums and search for Q45 throttle body, there are tons of threads on how to setup the TB.

 

[97gstnick]

Ok you guys have Dsmlink right? You don't need the idle switch, you can simulate it with the Dsmlink software, you can also offset the TPS to help get the idle correct. Go to the Dsmlink forums and search for Q45 throttle body, there are tons of threads on how to setup the TB.

oh yea, that is true. but the nissan tps might now work.....??? im going to see about using the stock tps.

 

[GVR4592]

The Q45 tps sensor will work.

 

[pneumo]

ahhh, thanks for the enlightenment.

maybe somehow we could mount the stock TPS like you said.... hmmm. im going to have to experiment. i have some sheet metal laying around, i'll let you know if i come up with something good.

No, I said iPS, not TPS. Use the Q45 TPS. There's a chance that we might be able to use a stock 1G iPS if we can mount it in a suitable location. I have an idea that should work, I hope to try it out soon.

 

[97gstnick]

No, I said iPS, not TPS. Use the Q45 TPS. There's a chance that we might be able to use a stock 1G iPS if we can mount it in a suitable location. I have an idea that should work, I hope to try it out soon.

how many volts have to run for the Idle position switch? 5 right?

 

[GVR4592]

The idle switch on a dsm doesn't have voltage, it's switched to ground. You don't need it, I'll say it again, Dsmlink can simulate the idle switch, you don't need it.

 

[pneumo]

Just for the record, I don't have DSMLink. I burn my own eproms, though I'm not sure if I have the skill to make this part of the code work for me? Hmmmm...now you've got me thinking again.

 

[VTEC_THIS]

I just bought my dsm off someone that has all the mods done to it including the infamous q45 throttle body. The idle is very rough, I start it and it bounces up to 1200 rpms and down to 200 rpms. If I drive it until it is completely warmed up and stop at a light my idle is consistently at 100 rpms. I never tuned these cars, and don't want to mess with the dsmlink too much since I don't really know what I'm doing. Plus I was planning to bring it to a shop to get tuned. Is there a way I can recalibrate it or adjust it through dsmlink without messing with the timing. Or a step by step thread because I didn't see anything. Also I heard there's two screws that allow you to adjust the idle but I didn't see them. Any help appreciated.

 

[cc4ever]

On the dsmlink cd there is a read me text that tells step by step how to adjust for new injectors and how to control your idle. Take a look at that and see if you can solve your own problem. When you figure problems out by yourself you have a much better understanding of what you are doing than someone telling you what to do. Just make sure your read everything carefully and do not go WOT or anything close till you know you have made the correct adjustments. If you still have problems or are still confused after trying that, I or someone else would be glad to help.

 

[VTEC_THIS]

I don't even have the dsmlink cd. I just bought the car, and the chip is installed and I downloaded the firmware on my laptop. Trust me if the information was right in front of me I wouldn't ask other people.

 

[da_reeseboy]

I don't know how much I can help since I have no real knowledge with your setup, but lets see what we can figure out.

You said the idle jumps from 200 to 1200 rpms when its cold, but when its warm it stays at a consistent 1000 rpm (I assume you meant 1000 instead of 100). If this is the case, you should start by checking for boost leaks. Those are the symptoms I had when I had boost leaks. It caused my car to idle like crap (even stalling) when it was cold, then just idle high when it was warm. Here is the tutorial on VFAQ -
http://www.vfaq.com/mods/ICtester.html
Let us know how that turns out.

- Jesse

 

[VTEC_THIS]

No, it wasn't a typo. My car does idle at 100 rpms when completely warmed up. It's a hair over zero, it comes very close to stalling but manages not to most the time.

 

[nanokpsi]

Did you log the TPS values/volts?
Just do that and follow what was said on the DSMlink forums. After calculating what needs to be done (i think they did that in your thread) just go into ECU>------------TPS
and the table will pop up where you need to input those values. If that doesn't help you idle, the base set screw for the q45 tb is on the bottom left front corner. You can loosen the lock nut and then scew the adjustment screw in a bit. Then lock it back down.

 

[VTEC_THIS]

I'm now having problems connecting to DSMLink, so I'm trying to get that done. Always something.....

 

[1992awdlaser]

I have the opportunity to buy a JMF intake and q45 tb combo for less then the price of the manifold would be new and have a few questions. When installing a q45 throttle body with this intake manifold what are the modifications required for the sensors? And what sensors do I need from the q45? Or should I just stick with a 1g throttle body. The goals for the car are a mid 11 second pass with the parts listed this coming summer. And a 10.80 or so the next summer with a Forced Performance turbo setup.

SBR 50 trim
Buschur fmic
Pte 1000cc injectors
ACT flywheel
SBR 3500 clutch
GM 3" MAF and MAFT
DSMLINK
TIAL bov
Ferrea stock size valves
Crower springs and retainers
Mildly ported head
Comp 101200 cams or Forced performance 2x's (need to decide)
SBR exhaust manifold (ported with wastegate on #1 runner)
Turbonetics external wastegate
Walbro 255 pump
Aeromotive FPR
Prothane motor mounts
Buschur 3" turbo back with no cat
Buschur o2 housing

I think that is about it for the parts but something might be missing. The only thing I don't have is the cams and I need to decide on which ones to go with also if you want to add your thoughts.

Also what head gasket do you reccomend? I was looking at the cometic gasket but don't know anything about which one to use.

 

[Syndicate]

My car is currently not in the condition to move anywhere for custom fab piping etc , I was wondering if anyone has gotten a kit to work with the 90mm q45 TB . I have contacted ETS alough no answer . And I will not be buying from SLS due to an issue .

Anyone know where I could possibly order a kit or at least the upper IC pipe ?

( I am not looking for fab work or match and fit kits. )

Thanks

 

[Boosted98gsx]

You can use any kit to the GM-MAF, then just use a 3" 90* silicone coupler to go in between the MAF and the TB.

 

[spinz4]

Buschur has a 3in upper pipe for use with a short route fmic. It is 150.00 and stainless.

 

[LilBeanTSI]

That pipe is meant to be used with the Buschur Race FMIC and Buschur sheetmetal intake. It most likely will not fit with another fmic or sheetmetal.

 

[Syndicate]

Yeps , thats why I need to find a "complete kit" :/