Ok So Here Is A Log Of My Surging Issue And Cold Start

[WogsRus]

well i have had my old and my mates TP on it, and i have set the base voltage on TP form 0.1v to .46 v and nothing changes.

I noticed all those things, but i do not know what that means in the big sceam of things. I think some of the things occur as a result of the ecu responding to the O2 change, saying that having the 02 compleately disconnected from the system did nothing and a near new 02 makes no differance.

By looking at those graphs do you think i am right i stating it's something electrical/tune/ecu related?

Also do a graph of VCT but i am sure it's not that.

[NewKleer]

whats shown in the graph i posted is minus all the data that doesnt matter. ie AAC didnt change, VCT didnt change, all the other registers didnt, temp was constant, etc.

because you can see the changes to injector pulsewidth/duty cycle/timing before O2 changes, the issue is that the ECU is changing injector output. ie, its not a fuel/ignition problem. most likely it is entering closed loop mode, though i dont know if the ecu will not use closed loop at all if O2 is disconnected.

because u said uve used a stock ECU, and a powerFC, and get the same thing, its probably unlikely to be ECU related, particularly if uve used a powerfc, though without output from fcdatalogit itd be hard to confirm whether its the exact same issue.

its also unlikely to be mechanical (aside from mechanical aspects of the TPS). if i had $100 and was a gambler, id put $40 on TPS, $20 on a knock sensor and $40 on "other"

if the temp wasnt as cold as 12C when u had the cold start issue, then coolant temp sensor may be the cause. lower the engine temp, the more fuel goes in. so you might be running too rich if the coolant temp sensor is off.

[TurboX]

well i have had my old and my mates TP on it, and i have set the base voltage on TP form 0.1v to .46 v and nothing changes.

?? - My TPS idle voltage is .30V and the TPS switch says off idle at .32V as soon as I start to accelerate. Dont know why yours would be so high?

I also had surging problems but seemed to come good when I fixed all possible vacuum leaks after AFM and around BOV plumb back.

PS Peter, soldered resistors to each knock sensor lead to fool ecu and no error 34! Unfortunately no knock sensors anymore either!!

[NewKleer]

u should replace the knock sensor rather than use resistor fix (unless you're sure its a wiring issue and knock sensor is fine). i had 34 myself so bought one from ebay USA (theyre nearly all the same part for nissans) for around $100AU all up.

[WogsRus]

my max voltage on the TP is .46v, it has always been around that. the closer to open TP it is the better the car goes for me.

Yeah i will check the knock sensors, hopefully on the weekend. Also need to check the whole system for leaks. If i put cylinder 1 on top dead center, will that mean i can presurise the whole system without any of the valves being open????

I definatly have no leaks from turbo out to manifold in, did that last night.

the hunt continiues.

[NewKleer]

with car just with IGN, watch TPS voltage in consult and ensure that it responds quickly to ur WOT. in those graphs, sometimes it instantly went to WOT (4v+), other times it hung around for a while.

of course if your driving style is such that you give it only enough throttle to be on the border of closed/open loop mode, then blips like that O2 are going to happen. it doesnt look that bad though

so was ur temp really 12C when u recorded that log?

[WogsRus]

humm yeah it was dam cold in the moring it snowed that night. From memory thoug the Water temp was alot higher then 12 deg C though. it looks like 60 to me.

Yeah sometimes i put the foot down, and i tried to see if i stick to a certain TP if it still did this.

[NewKleer]

ur coldstart log starts at 11C. but if that sounds right then no problems there. what car isnt hard to start at 11C?

u said u adjusted tps to 0.46v, but its showing 0.3v a lot, ie its gone down since u set it (and since it was low before, ie it must have gone down from stock setting to 0.1v before u put it back to 0.46v), its probably on the way out? either that or your expecting WOT conditions when you arent using WOT (ie ur not flooring it all the way/quickly enough), in which case there really isnt an issue there.

[Cubes]

Goign by Newkleers xls graph...

What confuses me is the injector duty cycle drop and increase ign. timing with steady airflow and tps values.

What else is taken in to consideration when determining load?

Ignition timing increase and duty cycle decrease is similiar to what would happen if it were using a lesser load point.

[NewKleer]

i would have thought AFM/RPM and TPS (tps more for the determination of cruising/load conditions for o2 feedback/closed loop mode, but also things like throttle enrichment for when throttle suddenly opens)

coolant temp and other things then affect theoretical inj pulsewidth for actual

because they are constant, i can only assume the time required for ecu to decide to jump into closed loop mode had expired before the final TPS jump to 4v occured - then it jumps right back out of closed loop once TPS reaches 4V.

in the logs other times the TPS goes straight to 4v (ie square/immediate jump), and there is no dip in O2

im not convinced that there is actually anything "wrong" with this though, and doubt a tiny blip like that is anything like R&R/fuel cut would be at WOT. i mean u cant expect 100% engine performance when the throttle isnt fully opened...

Yeah sometimes i put the foot down, and i tried to see if i stick to a certain TP if it still did this.

hmm, i guess the important question is then, did this R&R type stuff you noticed happen with the quick WOT (rather than the slower throttle openings?) since the logs indicate when TPS opened fully and immediately, there was no drop in O2 whatsoever (hence everything said about O2 is invalid if the issue was happening outside the places where O2 drops to 0 before u hit max TPS in those logs.

[WogsRus]

there a lot of info you just posted and it's friday morning. LOL.

the tp was reste to the value in the log as i was trying to see if maybe it was that. Yes it was 11 deg C, but the cold start issue had not problems last winter, and the car was eaven snowed in.

In regards to the florring thing, i was seing if it made a differance having my foot flat to teh floor or not, and more or less makes no differance. I am not really expecting WOT conditions down low, i just know that the car never ever did this before.

This morning it was so bad that when cold at 8 psi, i struguled to get up my hill, not only that but it looks like either valve seals or turbo sela is on the way out, as you could see oil plume smoke out teh ass end of the car. I confirmed this a bit by puttign my finger down the 02 hole and there was oil there, but the car doesn't use oil as it is still at the same level as befoe i topped it up, so it is propably the turbo seal.

I did some more checks of sensors, and i could not find anything, all volatges and resistances to and form the ecu to the sensor are OK, i only tested the main ones, there is still propably a dozen to go.

Also i adjusted teh air bypas a little, and added a bit of fuel into the SAFC at 800 rpm and the cr started fine this morning, will see what happens from now on.

I am going to disconnect the SAFC and make sure that it is not at fault.

Keep teh anwsers comming guys, it's teh only thing stopping me from going insane.

[NewKleer]

well then if there was no difference to what was happening at WOT to when u didnt use WOT, that dip in the O2 sensor means nothing, so its not a symptom. ill have a look thru the logs again tomorrow...got a uni assignment due midnight tonight that i havent really started!

[WogsRus]

sorry budy no idea what you mean?

[NewKleer]

if this "R&R like" issue is happening when you were WOT (no dip in O2) as well as when you were playing with part throttle (dip in O2), then the dip in O2 is meaningless/doesnt help work out what it is. ie the cause is not the ecu switching to closed loop mode (particularly if it happens on powerfc, as i dont imagine if they have closed loop, that it would work exactly like the stock ecu).

[WogsRus]

aaaahhhhh I C Now, sorry it is friday. Yeah full TP or part TP it's all thesame.

I am not sure but is it possible that is it fuel injectors being cloged up or something, possible a fuel pump failing, eaven though it is newish?

[docang]

coolant temp and other things then affect theoretical inj pulsewidth for actual

I've a gtt auto and its now having starting difficulties. Initially its was just the wiring to cas which was temporary rewired & after running for about 2 weeks there was problem starting. It cud still start with some diffculty, so got the fuel pump and regulator chged but also unable to solve. The starting diff was then traced to the water temp sensor.

Cold starting is fine but when engine got hot it cudnt start and upon disconnect the plug to water temp sensor the car started straight away. Connect back the plug the engine's still running with the TCS and slip check lites on. There cud be a circuit joinning the temp sensor to the TCS control module which is connected to the throttle motor control butterfly flap which wl not open if there's any problem with the circuit.

The engine's EGI wire loom is prbly screwed and have got a new loom on order to try and solve this problem totally.

So perhaps cud try this trick of disconnectg the temp sensor connector, start the car, plug it back, check lites on, warm up car, off engine, turn it back on & check lites off.... But really need to find out the actural problem affecting cold stars.

[NewKleer]

aaaahhhhh I C Now, sorry it is friday. Yeah full TP or part TP it's all thesame.

I am not sure but is it possible that is it fuel injectors being cloged up or something, possible a fuel pump failing, eaven though it is newish?

if it only happens around 3600rpm or whatever, but is fine at higher rpms, its less likely to be a fuel pump/injectors clogged.

try disconnect the knock sensor and see if that helps?...though its hard to get to.

checked that no wiring is shorting, particularly when engine moves a bit?

[WogsRus]

If i disconnect the knock sensor it goes to a defult 3000 rpm limit i think and set timming.

The wiring seams ok. will check some more.

It seams to be eaven worse now on cold weather.

[MANWHORE]

Newk, some really excitign knowlegeable stuff you've posted here. My car exhibits exactly the same doozy that wogs' car does. Might have to see ya during holidays (last exam is the 20th), so if you're free

[WogsRus]

HHHHHHHHHHHHAAAAAAAAAAAAAAAAAAYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY, guess what, the cars cold start is fixed. IT WORKS, all i did was well i don't know, i can't remember the last thing i touched, but it worked. IT WORKED, still splaters like a dog. LOL.