Need some install help for XFI

[jdpolzin]

I am in the process of installing the XFI into the GN. I have read a few things about people installing IAT sensors. Do I need to install a new one on the upper plenum? Anybody have any pictures of where they put theirs? Where is the best place to buy a new one? Or should I be using a MAT sensor? If so will this plug into the factory harness and where do I get one?

Also my car is a digital dash car, how do I go about a MAP sensor?

Also, where do you guys run the WBO2 sensor through the firewall? the fender is off so I can always drill a hole if need be.

And last but not least, I noticed there is one black wire cut on the Caspers box, is this normal? Doesnt seem to me like it would be.

Any help would be great, I'm new to this so if my questions seem dumb, please work with me on that!

Thanks for your help guys! -----Jeremy

 

[GNAT87]

For the IAT I drilled and tapped a hole into the dog house. I will try to post pics soon. I believe the wire on Caspers harness is normal. As for the WB02 I had to drill a hole ran it through under the carpet and sealed with silicone because the end connector is pretty big to fit through any existing holes. HTH

This is the way I did it, I'm sure others will chime in to help

 

[Chuck Leeper]

Use the stock IAT sensor, and the harness.

 

[turbojimmy]

If so will this plug into the factory harness and where do I get one?

Use the IAT that's installed in your air cleaner now and plug up the hole. I put mine in the back of my doghouse, which magically makes it a MAT. If you're interested, PM me and I can loan you my bit and tap. Used once - bought for this job and now collects dust. I think the bit and tap together were almost $40. Shipping to and from wherever you are has to be a lot less than that.

Also my car is a digital dash car, how do I go about a MAP sensor?

You need a 3-bar MAP. I put mine under the dash by the glovebox so I could plug it right into the Casper's harness. I tapped into my alky controller for vacuum/boost. My only complaint with Casper's harness is that he could've given us another 3-6 inches on the MAP and ground wires. This would make the installation of the interface box and MAP a lot more flexible. I soldered an extra length of wire on both the MAP and ground pigtails.

Also, where do you guys run the WBO2 sensor through the firewall? the fender is off so I can always drill a hole if need be.

I drilled a hole just above the frame rail. It came in precisely where I wanted it totally by accident. There's a wiring harness there so be careful. If you have the fender off you'll be able to see it.

And last but not least, I noticed there is one black wire cut on the Caspers box, is this normal? Doesnt seem to me like it would be.

Yes. IIRC, there are at least two. I think there's a pink one as well.

Good luck!

Jim

 

[jdpolzin]

For the IAT I drilled and tapped a hole into the dog house. I will try to post pics soon. I believe the wire on Caspers harness is normal. As for the WB02 I had to drill a hole ran it through under the carpet and sealed with silicone because the end connector is pretty big to fit through any existing holes. HTH

This is the way I did it, I'm sure others will chime in to help

Just a thought, would drilling this into the doghouse change the way the air runs through the plenum, making the Power Plate less effective???

 

[jdpolzin]

Use the IAT that's installed in your air cleaner now and plug up the hole. I put mine in the back of my doghouse, which magically makes it a MAT. If you're interested, PM me and I can loan you my bit and tap. Used once - bought for this job and now collects dust. I think the bit and tap together were almost $40. Shipping to and from wherever you are has to be a lot less than that.



You need a 3-bar MAP. I put mine under the dash by the glovebox so I could plug it right into the Casper's harness. I tapped into my alky controller for vacuum/boost. My only complaint with Casper's harness is that he could've given us another 3-6 inches on the MAP and ground wires. This would make the installation of the interface box and MAP a lot more flexible. I soldered an extra length of wire on both the MAP and ground pigtails.



I drilled a hole just above the frame rail. It came in precisely where I wanted it totally by accident. There's a wiring harness there so be careful. If you have the fender off you'll be able to see it.



Yes. IIRC, there are at least two. I think there's a pink one as well.

Good luck!

Jim

Jim, I will take you up on that offer for sure! I was just thinking that last night, "darn that drill and tap arent going to be cheap"! Every little bit helps cause I'm dead broke right now!!! Do you mind if I PM you a few questions as I install this? Thank you ----Jeremy

 

[turbojimmy]

Jim, I will take you up on that offer for sure! I was just thinking that last night, "darn that drill and tap arent going to be cheap"! Every little bit helps cause I'm dead broke right now!!! Do you mind if I PM you a few questions as I install this? Thank you ----Jeremy

Sure no problem.

As far as air flow with the sensor installed, I don't know if it's materially impacted. There would have to be some effect becuase you're interrupting the smooth inside of the doghouse, but the effect is probably negligible. Lots of people mount it back there. You can also put it in the intake itself, after the power plate, but the same question arises there, too.

Jim

 

[TURBO 6]

The wb02 connecter needs to be removed, then you can snake it through where the vac lines come through the firewall. Look way under the dash to the right, there's two vac lines coming through. You have to pinch the inner part and pull it toward you. Mine was really hard, but right before I gave up it came out. That will give you enough room to get the WB02 harness through. Get a coat hanger, fish it through, tape the WB harness with connector removed and then pull the hanger back inside the car. Done. No holes drilled.

 

[turbojimmy]

The wb02 connecter needs to be removed, then you can snake it through where the vac lines come through the firewall. Look way under the dash to the right, there's two vac lines coming through. You have to pinch the inner part and pull it toward you. Mine was really hard, but right before I gave up it came out. That will give you enough room to get the WB02 harness through. Get a coat hanger, fish it through, tape the WB harness with connector removed and then pull the hanger back inside the car. Done. No holes drilled.

I forgot to mention in my post that the hole I drilled was small. I used Casper's extension cord w/ the user-installed connector. Routing through an existing hole is even better.

Jim

 

[jdpolzin]

Ok, where do you guys think the best place on the plenum would be to put the IAT? In the back would be nice becuase the wires can be routed back into the harness and it would a nice clean install but that seems like it would definanately interupt air flow.

 

[jdpolzin]

Another question I have after fiddling with the car today is how do I identify a 3 Bar versus the factory 2 bar? I have a spare from a previous car and I'm pretty sure it's a 3 bar. Another question is my car has a digital dash, is there I place to just simply plug the new MAP sensor into to use the factory wiring or do I have to splice it in with a jumper off the plug on the Caspers Box and then just not expect the digital dash part of it to work?

 

[TURBO 6]

I spliced my map wire cause I didn't want my map sensor under my dash. Green wire on the big clear connector behind glovebox. Tie that into the middle green wire on the adapter module. Done.

 

[turbojimmy]

Another question I have after fiddling with the car today is how do I identify a 3 Bar versus the factory 2 bar? I have a spare from a previous car and I'm pretty sure it's a 3 bar. Another question is my car has a digital dash, is there I place to just simply plug the new MAP sensor into to use the factory wiring or do I have to splice it in with a jumper off the plug on the Caspers Box and then just not expect the digital dash part of it to work?

You can check the part number on the MAP against 3-bar MAP P/Ns that have been posted here to see what you have. You can check it with compressed air, too. The MAPs will put out 5V at their maximum. So, a 3-bar MAP should read around 5V at around 29-30 PSI (29.4). A 2-bar MAP will have the same 5V at around 14-15 PSI (14.7).

If you have a digital dash, there is an unused MAP plug sitting next to the Hobbs switch on the RH fender. Caspers has an adapter that you can simply plug into the factory wiring behind the glovebox that will allow you to make use of that unused, factory MAP plug. Or you can wire it up yourself. You don't have to mess with the wiring for the boost 'gauge' (orange and yellow lights) in the digital dash.

Jim

 

[jdpolzin]

OK so there is a plug behing the glove box? Is it a black and green plug? Or does anyone have a picture of it? I can pretty much make a jumper just as Caspers if I can figure out which plug it is. Where is a good place to drill in the IAT sensor into the plenum? I'm going to go ahead and work on that tonight. Hopefully the motor will be able to go in the car this weekend!!!!!

 

[turbojimmy]

OK so there is a plug behing the glove box? Is it a black and green plug? Or does anyone have a picture of it? I can pretty much make a jumper just as Caspers if I can figure out which plug it is. Where is a good place to drill in the IAT sensor into the plenum? I'm going to go ahead and work on that tonight. Hopefully the motor will be able to go in the car this weekend!!!!!

It's the foam-wrapped pair of connections (it looks like one big block, but there's two connectors there) above the ECM, near the glovebox. Evidently the MAP plug under the hood runs to this block. I don't have the schematics, but the Caspers adapter plugs into this block and has a pigtail that then plugs into the XFI interface MAP plug.

Jim

 

[HighPSI]

Here is a post describing EXACTLY what you are trying to do:

http://www.turbobuick.com/forums/performance-ecm-upgrades/209945-dfi-tunning-digital-dash-gn4.html

Here is the schematic for the (foam wrapped) C437 connector:

http://www.gnttype.org/techarea/electrical/connectors.htm

 

[northerngn]

It's the foam-wrapped pair of connections (it looks like one big block, but there's two connectors there) above the ECM, near the glovebox. Evidently the MAP plug under the hood runs to this block. I don't have the schematics, but the Caspers adapter plugs into this block and has a pigtail that then plugs into the XFI interface MAP plug.

Jim

just installed the harness the other day...
now the map sensor is back where it belongs
UNDER THE HOOD:wink:
have fun with the foam man thats stuff is glued on good...even after 20+years...wow
-dan

 

[turbojimmy]

just installed the harness the other day...
now the map sensor is back where it belongs
UNDER THE HOOD:wink:
have fun with the foam man thats stuff is glued on good...even after 20+years...wow
-dan

I never had a MAP sensor so mine didn't 'belong' anywhere. The instructions said to mount it away from engine heat and vibration, which doesn't make much sense to me. I'm pretty sure they're designed to live under the hood.

I have Casper's adapter/harness but it was too bulky for my liking. There's a lot to jam up behind the glovebox already without introducing that thing.

Jim

 

[jdpolzin]

Ok sorry to bombard you guys with questions. I am trying to figure out whether this spare MAP sensor is a 3 bar or not. On the port side, it has the numbers 43 17406 and on the back side it has the numbers 466 where it says GM and on the connector base it has the numbers 749 3356. Is this a 2 bar or a 3 bar?? Also, DR BOOST talked with me today and said I can just plug this directly into the MAP connector on the Caspers box and run a vac line to it. Is this good or bad? Then I can leave the Hobbs switch where it is and not mess with the Caspers harness. Sound good?

Also, just a question for ideas, in what position did you guys install you IAT sensor in your plenum?





Well, I just found out this is a 3 bar SWEET!! DR BOOST said the last 3 digits of the parts number were 749 but I didnt see the full part number on here. But anyways, any answers to the other questions?

 

[GNAT87]

Dr. Boost sounds right. My map is under the dash with a vac line run to it and pluged right in to Caspers harness. Everyone has a different way of doing things, that is just how mine is. If you do it that way try to run a dedicated vac line to it with no tees or any interuptions. Also, I dont believe it matters where the IAT sensor is placed. Some put it in the back, mine is on the passenger side. Its not a must, I ran it in its stock location for a while before I even put it in the doghouse. Of course with it in the doghouse the Fast gets the exact reading of the intake temp after alky and whatnot. I just remembered about the pic I was going to try to get for you, Ill work on that.