Well a couple days ago i installed the TB and frankencar midpipe,then started it it ran very rough. Then a look at my scan tool showed me it was running very lean i took it to the dealer to see if they could fix it, they coudnt spend real time today because they were very busy. But they checked my car on there scan tool and they confirmed what i knew the car is running 20-28% in lean condition thats how much air i am getting extra .If the dealer cant fix the lean condition will a super AFC solve my problem? They cant work on it till next tuesday If i can get the fuel i need sounds like a big power gain is on the way. I guess the track will have to wait.

 

im not going to pretend like i know a lot about this, but just to throw up an idea....Would higher flowing fuel injectors help to even out the ratio???

keep updating your progress, im very interested in what you find.

good luck

 

i dont see how because so many guys run boosted set ups using the stock injectors. they seem to push enough fuel when needed. I can't imagine a TB that is 10mm (is that correct) larger would require that much more fuel. sounds like a different problem than just fuel delivery to me.

 

how hard was it to switch the tb's

 

Maybe you just need to clean your injectors? I don't think you should be having that much of a problem. Ya how hard was it to install pathfinder throttlebody, someone should make a write-up for this.

 

did you reset your computer, or is it still thinkingyou have the old one installed? I don't know if this even matters.

 

It makes perfect sense. The MAF is calibrated to a specific volume of air and when you expand the diameter of the TB, the MAF ends up getting confused. Didn't Mardigras bore out his MAF to compensate for the size of the new TB?


Dave

 

I did that also ,10 mm doesnt sound like alot but it looks like night and day. My fuel flow with my scan tool was fine before the TB but after i started it the fuel was lacking instantly. Its not that im lacking alittle i am lean by alot. I also ported my intake manifold.

 

ohhh i'm really interested in this my mom is about to junk her Finder and i'm about to go rip her tb off. i wonder how much this will really help though....

 

Well just now for the fun of it i went outside and started checking and moving things around a little bit while checking the scan tool, when i thought i would play with the TPS sensor with the car running i moved it foward then back then tried to center it then my fuel trims went from 28% lean to about 10 % lean , but when i got on the gas it would spike into the 20%, but drop fast to around 10% and one more problem it idles at 1500rpm. I took it for a ride at that point and i can say for a fact that is the fastest my max has ever felt. And another thing i noticed is it puilles harder up top.if i could only solve these problems.

 

is it possible to install the pathfinder TB along with 370 cc injectors, and a SAFC and calibrate this to work on a NA application? If so will this net any signifigant gains?

 

and oh yeah, hey krismax, I badly want one of those adapter plates if you decide to produce them.

 

WOAH!! From what you just said, this sounds like an awesome and possibley simple mod.

I don't know much about MAF sensors, but I think dave b had the idea. If the MAF detects a certain amount of air passing through it, the ecu compensates for a certain amount of that air to go through the TB. With a larger TB, a larger amount of air is actually going through and the ecu isn't realizing this.

For example, say with the normal stock setup, your MAF detects X air and it tells the ECU "X air is passing through". Your ecu says "based on the size of the tb, when X air passes through the MAF, Y air passes through the TB" and then it sends the amt of fuel needed for Y amount of air.
With your current setup, the MAF detects X air, and tells the ecu "X air is passing through". Your ecu doesn't know the new TB size and figures, based on the old one that "if X air passes through the MAF, Y air passes through the TB" and then it sends the equal amt of fuel needed for Y amt of air. But with your New TB, Y is actually Y+something and you have more air but the same amt of fuel.

You might want to try fooling (those cheap things on ebay that say they give you 20+ hp come to mind) the ECU into thinking that more air is coming into the MAF than it is detecting (even though we know that more air really is coming into the engine).

im real glad youre persuing this as well. I say thanks!

 

Did you adjust the TB butterfly plate back stop? Try and adjust it so it sits more closed, I had to do this, I just eye balled it compared to the Max TB. I bet that is the problem. Or you may have a leak at the TB mounting point?

 

I always thought the throttle body was a major factor in holding the max back, got any pics, great job on getting this far?

This will be first priority when the waranty runs out

bump

 

Mardisgras, did you ever dyno before and after only the TB and MAF boring was done?

IanS

 

Thanks for the reply,did you leave the TPS sensor in the same position as it was when you got it? One of my problems probably also is the fact i was messing with the TPS clocking position. Now in regards to the butterfly plate back stop are you saying the PTB butterfly needs the same opening as the max TB , im not exactly sure how to do that? Another thing my car is lean from idle to redline. I thought mayby i needed a SAFC.Thanks. Chris

 

If you look at the PTB (MTB has a similar set up) plate when it is at rest, their is a back stop that is resting on a screw with a lock nut. Losen the lock nut and then turn the screw so the plate closes more. I am saying that it needs to be closed more than the stock plate because it is bigger. You need to set the TPS using a voltage meter. The Haynes or factory service manuals show how to do this. If you have not set the TPS yet, do that first. Its easier to do this with the TB unbolted from the intake because the TPS electrical plugs are in an akward spot. Take it off the intake and plug the electrical plugs back in, then set the TPS.

 

To everyone who was looking for a write up for the TB project, MardiGrass has some pictures on his homepage.....

I do have a stupid question though, what does it mean to "port" something (as in "ported MAF sensor")?

 

on your homepage, in the tb project there is a pic of a tray in your engine bay with, what looks like metal shavings in it. my question is what is this from and why? just out of curiosity. maybe im just missing something here, i dont know.

 

it is where he had to widen the opening on his intake manifold to accept the larger TB.

 

That might have caused the lean condition right there. It is a known fact that increasing the bore inside the MAF will lower the voltage given the same air flow. Going to a bigger TB might cause the MAF volt to go alittle higher but it shouldn't cause the car to run rough. I when I upgraded my 50mm TB in my 87max to a 60mm one, it didn't run rought at all. Actually it idled the same but throttle response was way better! As soon as you hit the gas the engine jumps . You should try a stock MAF to see if the car still runs the same. Generally if you bore the MAF the ECU has to be reprogrammed to run correctly.

 

Hello, when you backprobed the connecters was it from the gray plug or brown plug or one from each? From the voltmeter the black goes ? and red ? Thanks ,the haynes is not clear on this. Thanks for your help.

 

I dont remember which plugs it was, sorry.