Imediately starts then stalls R33

[treo]

As the topic said, my R33gtst starts then immediately stalls. The car will stay on if i play with acellerator pedal, though as soon as i take my foot off when the revs come down it stalls.

Ive check it for spark and injector pulse when stalling and its all fine. Fuel pump is buzzing away fine, i tried starting it without the airflowmeter pluged in and stalls at the same time an stays on if i play with accell pedal. I had a spare airflow meter, chuck it in thinking it would solve the problem but hasnt. IS it most likely the TPS?

I dunno but im a little unsure how to check my fault codes, ive removed my LH kickpannel to reveal my ecu. Im aware i need to put it in self diagnostic mode (mode 3) however cant see any led's or somewhere to select which mode to go into. Do i have to remove my ecu to do this because i cant seem to see anything on the side of the ecu that face out into the car.

Any help would be great with extracting the codes, not what each code number represents but just how to extract them ive already found heaps of info on that just no luck with now getting the codes

[riggaP]

I would've said AFM coz a similar problem happened to a mate of mine.

I assume the ECU is standard?

[predator]

you'll have to actaully take out the ECU, because conveniently the LED's face away from you.

I have a feeling the fault codes won't tell you much, but see how you go.

[Downforce]

check your intercooler pipes/silicon hose havent come lose.

[SERIES_II]

yer check ur pipes same happen wif me car

[treo]

cheers il pull out my ecu, i thought it may of been on the other side but seemed silly cos it should be quick and easy to extract codes

yeah it seems like there a big air leak intercooler pipe orsomething

il have a better look around, the other thing i just sort of remembered is a couple of times its stayed on for a minute or so. which leads me thinking its a component rather than a vacum leak

[treo]

yeah and my ecu standard

[treo]

Further investigatrion, and still no fix. My friend of mine who works at a nissan brought there scan tool around, the results. Nothing??? Whilst doing that i check all vacums lines and cooler piping and still nothing. There is nothing in my mind that can be obvious, there was no fault codes in my ecu, all the components i had some doubt about all were operating with in there range with correct voltage, and the graph there scan tool can display over time all appeared as normal, except maybe my o2 sensor was not a 100% but as would any o2 sensor that is still the original from factory. Also it should run even without that.

Im able to run the car with my foot opening the throttle as it tries to stall. So i could test all components at operating temp with the nissan scan tool as supposed too. Also if i sit there reving it anywhere above 2 grand but more like 4 to 5 grand for longer than 15 seconds, the car can hold an idle from anywhere from 10 seconds to say 45 seconds at most after its back to idle and my foot stops operating the throttle.

Anyone with some insite that would be great, another thought i had of what it may possible be is the 'Idle Air Control Valve' however it sort of make sense, i dont know how to check diagnose this correctly. Has anyone got some idea? feeback appreciated.

[paulr33]

unplug the airflow meter, do you have the same problem?

[predator]

Sounds more and more like fueling issue.. mine was same sort of thing.. would die at low revs.. once got going was ok, but could cutout at the drop of a hat. Took me a week of trying nearly everything to diagnose it.

Unfortunately I didn't have a scan tool to look at sensor voltages, etc correctly (something i must get soon) - but i think if you monitored duty cycle you'd see it suddenly dropping off before the engine cuts out

My ECU was reading same "all fine" even while the problem was occurring.. the stock ecu is not going to tell you a fuelling problem basically... as i don't think its part of the monitoring loop (unfortunately)

p.s. a fuel pump can still make noise, even if its fooked.

[BHDave]

It could also be the fuel pump speed control circuit.

I don't know exactly how the r33 runs it but on a 32 you have a big dropping resistor in the engine bay. if that is unpluged you have exactly the symptoms you are describing.

Basically, when the car is at idle it tries to drop the fuel pump speed, goes open circuit, puts no power to the pump and the car stalls.

You can chop the fuel pump speed control wire at the ecu (if you dont mind chopping wires as a check) and the car will then run the pump at full speed all the time. If it doesn't stall then you know the problems is with the speed control.

You could also listen for the pump when you have the car running, if it suddenly stops when you let the car return to idle then it could well be the same thing.

There are also some aftermarket pumps that dont like having a lower voltage and could be struggling to pump the fuel (if you have one that is)

hope that gives you another lead to follow anyway.

Cheers

[treo]

Cheers guys thanks for your input

paulr33

You car should run without the airflow meter, it wont really drive but will hold idle.

I always thought car will stall without afm but when we tried it on my friends R33 the other day ran fine at idle, also i had a spare an chucked it on straight away an nothing.

predator

Cheers for your input, im glad your thinking fuel. It seems logical to me also, what about fuel regulator being faulty??? Could this be the cause. I know what you mean by the fuel pump also, they have a tendency of shitting themselves especially if its buzzing becomes louder. The fuelpump is the standard item and im pretty sure its not the problem, however touch wood. Il have to do a fuel pressure test which i should have already done however i dont have the gauge.

BHDave

Thanks thats another logical possibilty 'fuel pump speed control circuit', something i know very little about but definately worth looking at it tommorow. Thanks for the explanning. However my only doubt being when the car stalls you can still here the fuel pump buzzing away when you put your head next to the tank cos the ignition still on. However it could stop for a couple of secondsthen run on again straight after, hence being faulty the 'fuel pump speed control circuit'.

Thanks guys

[paulr33]

when my car is running and i unpug it, immediate stall. when i start car with afm unplugged immediate stall

[rob82]

When the car holds the idle up pull the IAC plug and see if changes RPM sounds like your IAC might be stuffed, blocked ect.

[INASNT]

when my car is running and i unpug it, immediate stall. when i start car with afm unplugged immediate stall

Thats right, coz as the afm plug is unplugged the ecu wont detect the air signal voltage so it doesent know how much fuel to add so it will stall.

If you ever go for a epa test this is 1 of the things they also check

[treo]

The ecu will compensate for know afm meter signal but will run in fault mode, hold idle like a pig but it will run. Unplug your AFM and start your car, and see what happens.

[INASNT]

It might run but it wont rev past 2000rpm.

Sorted the problem out yet?

[treo]

Ok i had a good look at quiet a few things on the weekend, yeah thats right about the afm i think mine limits at 2500rpm. It will run if unpluged before started. So the other day i had cleared all the fault codes with a nissan scan tool, so on the weekend i recheck it for fault codes the old fashion way with leds. It came up with nothing, code 55, like predator said codes wont tell me much.

Anyways my friend at nissan told me to clean my throttle body out and to adjust base idle again and it may not stall, he seemed to think it was very important to adjust the base idle. I had cleaned my throttle body the other week but never readjusted the base idle, so i tried to however appeared to be fully adjust as low as possible manually. So i adjusted it out a bit to idle at 1400rpm an know my car holds idle, the idle previously was 800rpm at operating temp, so that should have all been fine. I adjusted it back down when warm at what it should be and it began to stall again.

So i look into BHDave and Predators advice about the fueling issue, it seems as though BHDave may be onto something, i listen in the boot to see how the fuel pump was operating it was running then all of a sudden for about 2seconds you would here the pump switch off, then as the car would stall the pump was switching back on.

So now i need to find out where the fuel pump speed control circuit is exactly, how to fix for the problem, and im really curious as to where this big dropping resistor is in the engine bay is exactly?? And after all that about the last 15 start ups it hasnt stalled, however im not one to ignore the problem so i need to find the fix even if its not doing it now.

So anyone with any knowledge of fuel pump speed control circuit would be of much help.

Thanks guys

[sigsputnik]

this may sound dumb, but what does the fuel pump sound like? i'll find it in the boot, won't i?

[knore]

Im currently having a similar problem, except mine will idle for awhile then just drop in revs and stall for no reason.

Its definately something to do with fuel, i just drove for 30 mins without a problem.

But then went to accelerate after turning and stalled again

tis always something simple, just gotta find it