michaelnyden

iTrader: (15)

so I just installed a spare de-k TB I had laying around that I had bored out...my question is after the install, my idle is at 1000 rpm...I adjusted the TPS every single way possible, the only way the car will have a stable idle is when it is at minimal voltage according to my multimeter...in other words, only when the tps is adjusted all the way clockwise as possible, will my idle be stable...anything else, and the idle goes higher and bounces quite a bit.

also, when the car is off, my throttle cam/drum lightly rests on the throttle stopper (the brass diaprham on top of the throttle body that has a single vacuum tube coming out of it and a rod with a boot on it)...when the car is on, there is a rather large gap between the cam/drum and the stopper as when it gets vacuum it moves inward towards the diapram...but how much gap is there supposed to be...as when I push the throttle cam further closed in respect to the butterfly plate, and it finally touches the rod, the idle goes back down...also, now, when I rev it to any rpm, it pauses for a split second after I let off and then drops, then stops around 1500 for a second, then back down to 1000 rpms.

I did the IAVL procedure 5 times with a stopwatch and an OBD scan tool to make sure all the preconditioning was 100% right, including the timing and coolant temp as well as my battery voltage were all perfect, it simply doesn't do anything...in addition, with a consult II, it never completes this process it just keeps running the intake air volume learning procedure and my idle doesn't change...I have no vacuum leaks, and my tps checks in tolerances as according to the FSM.

I wish we had screws on our IACV's like the 4th gen's which allowed to them to tweak the idle!

VaporHead

Maybe the TPS is bad? IACV, EGR Valve?

michaelnyden

iTrader: (15)

I switched all of that stuff from my original throttle body which was all working perfectly before I switched them to the new throttle body...in other words, all I changed out was the actual throttle body, but reused all the others stuff which was working perfectly before hand.

VaporHead

This may be a dumb question, but, did you reverse your throttle cables when reinstalling?

nismo_star

iTrader: (8)

you just shorted out your ecm with a bad iac on the TB you just put on

michaelnyden

iTrader: (15)

not possible...my iac is testing perfect with multimeter...within spec readings...and is the one my car came with...if you read above, I switched all of the items off my old TB including tps and iac and moved them to the new TB...which were all working perfectly previous to TB...so I am thinking it has to do with the TPS adjustment or a throttle opener adjustment problem...

vaporhead...what do you mean by reversed throttle cables? how is it possible to do that? there is only one way they should face...

nismo_star

iTrader: (8)

seen it happen before, your best bet is get the iavl set, but the "other" procedure which has worked on situations like this is to have someone sit in the car and rev the car and disconnect the MAF, forcing a p0100 code or even disconnect TB if the other process doesn;t work.
you must kill self learn to 100% and also on consult make sure idle rpm adjustment is set to '0' compensation, and then perform IAVL, if rpms do not
change, shut off the car so it shows INCMP on consult w/ key on, engine off.
restart car and hopefully rpms will be in 800rpm range and IAVL will be able to adjust properly. Last hope is to make sure TPS is dead on as per FSM and do the process all over again. good luck.

note: I have seen others who have modded TBs oversize and were never told that the iac was bad or tps shorted out, from a used TB and once hooked up, cook an ecu or egi relay. I was able to save some of these members, but I hope you have good friends in dealerships

michaelnyden

iTrader: (15)

well, I reused my prefectly working TPS and IAC...of which was working with my oem TB only an hour before...so I don't think any of those shorted...I seriously think it is how I have everything adjusted/installed...

I never plugged in the IAC or TPS in to my car that came with the extra TB I had bored out...

so when the car is off and the throttle stoper doesn't have vacuum, my throttle cam drum/stop rests on the rod coming out of the throttle opener...but when I start the car, there a large gap (1/4") between the opener and the drum/stop at idle...is there supposed to be that much...? and when I rev it, the throttle cam/drum stop never hits the stopper on the TB, there is a gap there as well and I have slack on the throttle cable which is strange...something else is not allowing it to close all the way I think...

NmexMAX

iTrader: (22)

Is the throttle plate as large in diameter as the new TB?

michaelnyden

iTrader: (15)

yes...it's almost too large...it gets slightly stuck on the walling if you force it further closed than the position it sits when your not touching it...

NmexMAX

iTrader: (22)

That could cause an erratic idle.

michaelnyden

iTrader: (15)

well it doesn't get stuck anymore...but I was wondering about the huge gaps...isn't the throttle cam/drum supposed to rest on the stopper when? I'm gonna take everything apart and see what I can do...this situation is difficult cause I can't rule out something physically installed wrong yet or a sensor being uncalibrated...

xx-Marshall-xx

iTrader: (15)

oh sheesh... i hope i dont have this much trouble when i install mine

NmexMAX

iTrader: (22)

Slightly OT, but theres a restriction before the TB, and that would be the MAF... So why coke bottle it without working from the smallest DIA to the largest, and upgrade as needed.

michaelnyden

iTrader: (15)

cause I doubt the maf is restricting much flow, the maf is pretty large on the 5th gen...it's the TB and after the TB that is small...

so I took it all off and put it back on this afternoon...I need access to a consult II again...lol...this do it yourself thing is so unreliable even if you follow the FSM instructions perfectly...I found out that the only thing I didn't switch over from my stock/oem TB was the throttle cam/drum..which is different than the '01 TB I had bored out (I have a '00), mainly the stopper, it still didn't fix everything, but it fixed some things.

NmexMAX

iTrader: (22)

It's the same size as the 4th gen.
My TB is larger than my MAF (A33B)

michaelnyden

iTrader: (15)

really? my TB seems considerably smaller than my maf...maybe it's just an illusion

michaelnyden

iTrader: (15)

marshall...I doubt you will have as much trouble...you have many different solutions to idle correction, whereas the 5th gen is all sensors and crap...so it's very hard to get working unless you have a consult II handy...

NmexMAX

iTrader: (22)

Things aren't always what they seem.

Perform a measurement to make sure, as the 3.5L may actually have a larger TB.

michaelnyden

iTrader: (15)

okay, so I talked with a recently retired nissan master tech friend of mine today that told me the big bore TB would throw way off the iacv...he also said that if the TPS is within spec, the iacv will self learn after a bunch of drive cycles...but it won't be a gradual response, it will all of a sudden drop to normal idle and act normally...or you can use the consult II as he was saying, but since I don't have access to one anymore...I have to wait to drive out to his house and use his...

my only problem right now is I have to burn the hell out of the clutch off a stop in 1st gear as it takes a lot of revs to get going smoothly...if I give it only a little gas like I used to do as I slip out the clutch, the car will rev to about 1500/1600 and bounce, then buck hard/jerk once or twice and then will be fine after that in every gear...it's only when I am at a complete stop and have to get going again....

NmexMAX

iTrader: (22)

I bet a larger MAF would've been easier to accomplish with similar results, with a safc or some other tuneable entity of course.


FYI, the DEK TB is smaller than the 35DE (72mm vs 65mm, so in essence, it is the same size as the 4th gen TB), so I guess getting the Tb larger is a good option in your application.


This self learn feature, what exactly is the IACV self learning? I would like to know specifics, such as sensor paramters (i.e what data values were affected with the boring?).

And once you know that, you may be able to change/compensate and bring it back to normal without any drivecylces)

By drivesycles, what does he mean by that? X amount of startups, self learn via the CEU which is dependent on driver characteristics?

michaelnyden

iTrader: (15)

yes...he means x amount of miles and cycles of the ignition as well I think...but thinking back again, I think I may know of some other issues...I don't recall replacing a gasket between the TB and intake manifold....so that is probably an issue as well...and I should then check to see if I put the gasket back in that attaches the iacv and bypass to the bottom of the TB as well since I don't exactly recall putting any gaskets back in after the install which would mean unmetered air...I think I will just stop by my local nissan dealership after work 2morrow and pick up some new ones...since I don't even remember where mine are...

he also did say that since after I try and do the self induced without consult II learn procedure...it pulls the IACV engine code P0505, it does not mean my sensor is shorted or faulty or the ecm is fried in anyway, he said this is simply because either the stepping motor is dirty and stuck (which in my case it is not since it was working one hour before the move to the new TB)...and since I never plugged in the iacv from the bored out ecu, it is impossible to have fried anything, rather the code is pulling cause the sensor is giving off readings outside the expected norm for the ecu previously learned map and hence is thinking the sensor is faulty, therefore I need to either have it learn or force it with the consult II...

NmexMAX

iTrader: (22)

It shouldn't be a big deal, as I didn't change it when I did my MEVI (4g). So, with that said, the said unmetered air entering should not be significant enough to skew MAF(a/f) readings.

What is the new diameter of the bored TB?



Explain self induced? Sellf learn? Throttle position? Air Volume learn?


I'm sorry but,
I'm familiar with A32's and A33B's, but it seems as if A33's(5.0gen) are a semi mix of A32's and A33B's with respect to electronics. me=

michaelnyden

iTrader: (15)

no, I mean, I don't recall putting one back in there at all...so it's TB to manifold....no gasket...same thing for the iacv on the bottom of the TB...

but your right about the electronics, in large part, the 5th gens blend 4th gen sensor and ecu programming with some new stuff as well until it was all thrown out the window and new in the 5.5gen...

self induced meaning, inacting a learn procedure upon the ecu by using a method stipulated in the FSM (factory service manual)...

self learn meaning, the ecu learns on it's own without inducing any procedures over time...

throttle position meaning the position of the TB (the butteryfly valve from fully closed to fully open) which is metered by the TPS (throttle position sensor) which is basically a pentiometer which outputs specific resistances based on the position of the butterfly valve in the TB...

air volume learn is a self induced procedure commonly done with the consult II diagnostic system/computer that they use at dealerships to help sort out sensor issues/problems...it causes the the ecu to learn the new range of readings it is receiving from the iacv and save them in memory and then offset the iacv motor to correct the idle based on the difference in previous range and the new readings...

NmexMAX

iTrader: (22)

I know what all that means, I was just asking you to clarify what your master tech did/performed and how he came up with what he stated.

Can you do the self learn on your own(DEK), or is that only a consult II procedure? I can do it on my own in my A33B...that's why I ask. Could be because I have TBW, and well, that =/ IACV.


Do you have a wb to monitor and clarify?

michaelnyden

iTrader: (15)

oops...sorry, I guess I miss read your questions...

the master tech didn't perform anything yet...I called him since he is a friend of mine...he told me to go over my installation and make sure everything is perfect with no vacuum leaks and then the car should self learn over time, or I could come to his house some weekend and he will do the IAVL procedure on his consult II

there is a way to self learn on your own on the dek according to the FSM but it is highly unreliable since everything has to be done perfect (there are too many variables/steps that could be missing something along the way which would inhibit the IAVL to proceed)...whereas with the consult...it is forcing your car to do it...

but in my case, I don't remember putting back either gasket as I mentioned previously which would make a huge difference in senario...