I hate to post a thread about my vague, (once again), intermittent problem. I changed my spark plugs last week and the rear middle chamber had oil pooling up and on the spark plug. I changed the spark plugs, cleaned it out, start the car, and it idles WAY BETTER than it did before (for a couple days at least i think the throttle cables were just too tight). I am running NO IACV and its always been a little low.
A usual cold start up will consist of me revving the car until it can idle by itself just under 500 rpm. During driving before the car is fully warmed up the rev's will go VERY low sometimes even to ZERO and jump back up when i press the clutch in to bring it out of a gear (like coming to a stop). I figured this was do to the lack of the IACV. It never really would stall though, and this may or may not be related to my problem.
Recently I have gotten a hesitation when shifting into 2nd and maybe 3rd gear which i thought to be a slipping clutch (its brand new, 5th gen a couple thousand miles on it) it would remind me of how a misfire felt in my auto 3.0 where it accelerates slowly and then "catches" suddenly and normal power comes back.
well..i was pissed off and beating on the car yesterday on some empty back roads...I took it to about 110-ish and would press in the clutch, bring it out of gear and the car would stall completely...all electronics worked fine..i could start the car back up. It did it about twice..and would die if i didnt rev it up upon restart. It idled fine for the rest of the way back.
today the car was almost fully warmed up and it stalled in the same situation as i was cruising and shifting into neutral. I turned the car back on and it died again...started again and revved it up until it would idle by itself. When i was revving it there was this terrible delay between when i would press the pedal to when the car would rev up...it was as if maybe fuel wasnt being injected but the throttle valve was opening. I could hear the "sucking noise" after the delay and the car would rev up but it was being very slow about it. I revved it for a second and drove normal the rest of the way and then back home.
what could this be...another faulty FPR? it was reading 51 psi when i checked before i left. it runs fine 99 percent of the time...but then i get this crap and i feel like something is on the verge of rendering my car inoperable. I noticed my CAI came disconnected and i thought that might have been the reason for the stalling although the MAF is connected right to the TB.

 

maybe your tb is too closed so your idle is low. how is your tb cable attached? i know mine can be bent a bit, and raise/lower the idle that way. could your maf be dying? i know the hesitation you are talking about, my intake came off the tb. are you getting any codes?

 

i've got codes galore from the 5 speed swap though and some 02 sensors. I'll check the codes again tomorrow since the problem was pretty bad today.
I know when i was setting up the TPS parameters I couldnt get the WOT one high enough or something like that it was off a little bit. I guess it could be my tb too closed the cables are loose than i originally had them but they still dont have much slack in them, it only started doing this recently.
i'm fairly confident this is an intake problem...can anyone remind me of the parameters the TPS is supposed to be at? I just remember i was turning it all the way and could not get the right number from the the PF tb.

 

What do you have your TPS set at right now ?? at idle and WOT ??

I was having the same problem when my tps was off just a little bit.

-matt

 

i dont remember exactly. I'm going to check again today but i forgot the parameters. I just remember i was maxing it out, turning it as far right as the screws could allow it to go and it was still too low. There were secondary spots to put screws, further to the right, but then it would have turned the TPS too far.

 

You may need a NEW TPS.

I have a Pathfinder TB...Having it set to .5ohms at idle, doesnt alow it to be at 4ohms at WOT. I may move it to about .62, where WOT would be 4 exactly....I ran that for a while, and ran great....I had it at .72 idle, and that caused it to stall immediatly like your explaining.

-matt

 

ah i see. well thank you. i'm gonna go play with it in awhile and see what its showing. I know the tps is only a few years old, i bought it new but who knows. I am more worried about setting the WOT ohms first since you can adjust the idle opening with that screw changing the idle ohms.

 

Hey matty, your #s are correct but the units for those #s are in Volts. At idle it should be at ~0.5v and at 100% throttle it should be at ~4.1v.

One could indeed check it through ohms, but I dont recall the equivalent ohms #s off the top of my head.

EDIT- Mine is set to .570v at closed throttle, and 100% throttle is like 3.95-4.0v. Runs just fine though. My SAFC1 reads 100% thorttle so Im happy.

And yes, while I had the e-TB with a rigged on TPS braket that allowed for play, I experienced the same exact stuff. Also, find a better way to rig that throttle cable. It being loose doesnt help one bit. Also, use a screw or find a way to stuff something bet'n the idle screw and the butterfly spring thing to raise that idle. That is way too low.

 

Notice what Im using for a throttle cable bracket, that's an ubber thick piece of metal from an exhaust hanger. You can get it at any parts store. Made one hole large enough to run one of the elbow's bolts to the IM through the bracket, and made a V-notch at the end for the throttle cable itself.

That sucker does NOT move one bit one bit :-D

Labor credited to streetzlegend

 

I'm using the stock bracket bolted into a thick piece of aluminum.ill take a picture, I know its not the problem.
it usually idles around 650 but it variates...the needle will move up and down...the car has a lumpy idle which I've figured just to be due to lack of iacv.
Still haven't gotten around to checking the tps..I will later this afternoon.
Thanks guys

 

sorry about getting back to this thread. i've been busy.
when the car is cold, i get the stalling...when it is warm, i rarely do if at all. today it happened twice upon driving my car right after a semi-cold start. The rpms dropped, and i sat there cranking, pressing the pedal for minutes repeatedly until it FINALLY started up. And when it starts up it has the most horrible idle for about 3 seconds while i'm revving it and then it returns to normal. what it started to feel liek actually...was an intake leak. I was afraid at first (always thinking the worst) that a chain tensioner failed and my timing was off. but the way its intermittent is starting to make me think i have some ****ty gasket failling me and causing enough of a leak to stall the car when its cold but not when its warm. I have gasket material between the TB and adaptor plate as well as between the manifold and adaptor plate. I had to remove my manifold recently for the spark plugs and maybe i messed something up? The bottom of the PF TB is sealed with gasket material and a metal plate.
anyway, tomorrow i'm gonna tear it down, mess with the TPS, and see if it stops...i really hope its this simple.

 

I had the same issues(the car stalling and sometimes dying on me) and I replaced the right bank front O2 sensor(because it was throwing the code) and the problem went away. I still have the hesitation problem when transitioning from 2nd to 3rd, sometimes from 3rd to 4th, and when I give it half throttle right away in fifth.... its kind of like a juking feel, like if the car is starving for gas. I know my TPS is slightly off.... at WOT it read 3.6 volts, so I need to fix that.

I also had the idling issue, and I dont have the IACV connected. Now that the O2 sensor was replaced, I really dont need to give it gas for it to idle properly... When I start it, the car starts up right away... the rpms drop to about 300 rpms but quickly jump up to 700rpms ans stays there.

IMO, replace your O2 sensor(if its a primary) and you should resolve the idle issue and the dying out on you issue.

 

yeah my o2 sensors are bad...even though they arent that old. it sounds weird that they would cause that kind of thing but your symptoms do sound like mine, "it sounds liek its starving for gas". I'm gonna try the free **** first haha and then get to the 02 sensors.
thanks...and why is your tps off? did you have the same problem as me? it wouldnt turn any furhter?

 

Its just that I went with the ETB and I made a custom bracket for it. I need to loosen the screws and re-adjust it. I never really checked the voltage when I installed it until I got my VAFC II and it read 3.6 volts. I just looked at it and it seemed to look okay and aligned(i know I know... thats not the right way)
YOu might have banged the O2 sensor or something... they're sensative sensors... When I did my swap, I had one of them hanging from the engine bay and I think it might have touched water or ice, becasue it snowed during the swap.

 

haha i freakin hate the tps. I know on other cars you cant adjust them if you wanted to, they only bolt in and stay in one place...why the hell cant ours be like that.

 

FTMFW! Thank you! lol

 

i went by the haynes specs and adjusted it that way 4-k ohms at wot and .5 k ohms at closed throttle. It was a little high at WOT but like i said, i had it turned all the way clockwise that it would go...it was at like 4.18 or something..thats as low as i could get it to go. I left it there and decided to adjust the idle instead since it was at like .3X which seemed low and could possibly be the reason for the stalling. So i adjusted it with the TB idle screw and got it to .5 but now the car idles at like 1500 rpm. I know the TPS takes a minute to adjust, so i drove it around the corner and back and it still idled real high. I didnt re-set the ECU, not sure if that makes a difference. I dont know what to do if i cant move the tps any further clockwise and the car will idle too high at .5k ohms. Maybe i can bring it down to .4? Matty mentioned his was actually higher (.6)....

 

alright...i took it all off the car again, I made sure the TPS "Tab" was in front (being pushed) by the throttle and it was all mounted on there right. Heres pictures of my throttle cable mount (because i said i'd post them) and pictures of how my tps is set up. It can be mounted where the harness connections are facing the passenger side or driver side but the ohms read the same. I have the TPS pushed as far clock wise as the screws will allow it to go and it reads 4.18 at WOT..thats as low as i can get it...but to make the idle right i'm going to have to lower the idle screw again and bring the ohms for that down to .3-ish range again...
i've been worrying more about the WOT setting since i can adjust the idle screw for the idle setting...but I think i've hit a wall here...
maybe i should just hook up my IACV...although i dont know how that would change the fact that the car does NOT want to start whenever it dies due too this problem.
next time it does it i'm gonna unplug the MAF and see if that changes anything..my CAI did come detached and i noticed some debri on the filter screen of the MAF yesterday.

 

yea IACV has nothing to do with it as long as the idle screw is set at a reasonable level and the TPS is in sinc. I dont have one and when I start the car it revs to 1300 then drops to ~920 on a cold engine. Warmed up it sits around 750ish with no problems.

You mentioned that while adjusting it the idle shot up. Same thing happened to me while I used to adjust my TPS with the ghetto brackets on the 3.5 eTB. Sometimes I'd push it too far CW or too far CCW and idle would go up to 2500-2000. Just a matter of getting it within spec, then adjust the idle with the crew like you're saying.

 

no the idle didnt shoot up while adjusting anything...it raised to 1500 because i opened the TB too much at idle even though thats what it took to get it within specs. I dont know what ohms its reading at but i have it idling at about 750 now (although it still sounds like its idling too high) It used to idle at 650 and have a little bit of a lumpy sound to it. When my car starts from a being completely cold usually i have to rev it up to keep it from dieing and then it will idle at like 400-ish and raise up to 650 when warmed up.

i dont know if your understanding what im saying but its pushed as far clockwise as the screws will allow it to go and its still not within spec for WOT (off by about .10) the idle is definently not within spec its probably down at .42 range. I guess it doesnt matter as long as the the car is idling okay but Im starting to doubt its the reason for the stalling. If nobody else has their TPS turned all the way CW then something aint right with my set up.

ugh. this is frusterating. i'll see if it stalls out tonight when i'm at the track and letting the car sit between runs.

 

Check the PCV valve, that might be contributing to the oil pooling and it definatly can lead to hesitations if the pressure is off in the crank case.

 

Yeah I'm gonna go ahead and change that, I've also been advised to change the o-ring gaskets inside the valve covers...I hope those things prevent the pooling..
The hesitation doesn't bother me as much as the car stalling and then not re-starting. When the car stalls while rolling it'll start up fine...but when it stalls while the car is not moving its so difficult to re-start.

 

car has been fine all today even at the track, it does not dip down at all between shifts anymore and idles decently (although louder than before and higher). I still get a little delay when i quickly press the gas where you can hear a brief sucking of air and then the car revs up....that still sounds like a TPS problem huh...