Sluggish 3.5 swap
 

Let me start with a little preface.

I have a hybrid 3.5 swap. With de-k fuel rail and injectors. I am also running a EU so i can data log ect ect. I havent hooked up my WB yet due to lack of funds and i need to get a y pipe to eliminate the precats.

so ive had a 3.5 swap done for about a month. When i first installed it, it had good power.

But lately it seems like my timing is being pulled. I have been using the 470k resistor for the KS. It seems like it does well for a day or two but after a few days of driving the ecu seems to pull some timing. Today i cut the harness and wired up the resistor right where the harness goes to see if its the harness is bad.

When i first swapped i was running mid 20*s at wot all the way to redline. I can feel it being slugish around the 3k-4k mark

Now from 3k-5k it will bounce around and i will be in the high teens for timing. I think it is related to my KS. But im not sure if something else could be pulling my timing. IE another sensor.

As for codes.

I have one for a TPS(not running one, Very well could be the culprit but i havent had one hooked up since i swapped and it seemed like the power was there when it was up and running) I modified the 5th gen TB to cable driven and didnt fab up a bracket for the TPS

P0150 which could be from diking around with the KS. I recently tried the 3.5 KS which didnt work. I will probley swap out the o2 sensors any ways when i put a y-pipe in. If the code still exists. I will reset the ECU again to see if it will pop back up. But even if it is bad i still dont seeing it pulling timing.

Also when i add timing into my EU, It will add timing but not all of it.

IE say i add 10*, I will data log and it will show a adjustment in timing of only say 9.2* and not the full 10* of advancement

I will datalog a base run today and post it up to show whats going on with it

Im sure i will add more to my symptoms but this is all i can think of for now.

Mods if you feel this should be in AM section by all means move it.

Any suggestions, opinions(good or bad) are more than welcomed.

http://i248.photobucket.com/albums/g...02/rpmbase.jpg

http://i248.photobucket.com/albums/g...k0002/base.jpg

No timing added anywhere. Just the 4th gen ECU controling the timing

P0150 shouldn't be due to messing with the KS.
Code: P0150 | Description: Closed Loop Control
http://boredmder.com/ecucodes/1996/0308.png


You're just not running a TPS? I'd definitely use a TPS, then see what sort of issues you have. It's designed to run with a failing/failed TPS as a 'safety' precaution, but certainly not designed to run without one indefinitely.

Yeah i know. Im contimplating on just whipping up a bracket real quick for it. The thing i dont understand that ive been running w\o one since i swapped and havent had issue's up till now. Im still going to put it in to eliminate the possiblity.

Thats good to know that it does have a fail safe mode and what not. Do you think it would pull timing though??

The reason why i "think" that messing with the KS set off the o2 cel is cause every thing i searched on about p0150 came up with the KS right next to it. Everytime. Thats why i just assumed that a bad KS also throws a code for the o2

i think i read that its recommended for 4th gen 3.5 swappers to ground the KS directly to the negative terminal of the battery to have 100% timing. is this how u have the KS now?

uh.. what difference does it make... the entire car is a ground

Do you expect the block to be as great of a grounding point as going directly to the negative terminal of the battery?

Thread: http://forums.maxima.org/all-motor/5...y-request.html

That's irrelevant, he has a resistor.

I would get a tps on there and fix your primary o2 popping up that code before anything else. As for that code popping up with the knock sensor code, you will hear that mentioned with nearly every code because people usually had no clue the ks code was there all along.

yeah, i had that same code w/ the knock sensor. read the same things about it that you did so i changed the ks and haven't seen either one since.

Due to the thinner walls in the vq35 there is more noise going on therefore the 3.0 KS will pick up on that as a knock therefore retard timing


Im on top of that. Actually i think you can help me. I was reading in some previous posts about you doing the TPS bracket out of some JB Weld bar.

could you please elaborate on this and possibly post some pics?

uh yea i do.. if is grounded correctly... that's why when you do a jump start you put the negative to the engine not the battery... that's also why the starter has no ground running directly to the battery.. and if it can turn my engine when its 0 degrees outside then yea i think its just as good as the ground terminal..

the only thing that this might be good for is like the tread says.. to get rid of the vibration caused by the thin walls of the engine...

The center of the block will never be as good a ground as the battery terminal. It may be close, but never the same. You speak as if there's no resistance between the two at all.

And as far as the jump starting thing, that's all personal preference. I never have and probably never will see the need to put the negative clamp on the engine instead of the battery.

eh thats warm out here when its the middle of winter.

Measure the difference in resistance with an milli ohm meter and with meger tell me how different they are compared to going directly to the negative post..

What the hell is a 'meger'?

If I cared enough about this to prove my point, I would. As it is, there will be a difference.

megger is a mega ohm meter... sorry 2 g's..

anywho the difference will be less than an ohm.. or unmeasurable

Like everyone else stated, get a TPS sensor on there. i know my car ran funny when the tps sensor was off voltage. Someone correct me if im wrong but without a tps sensor how does your car know its going wide open throttle? it doesnt AFAIK. The ecu could very well possibly running some defaiult map to keep the motor from detonation, thus the reason for being sluggish.