Imediately starts then stalls R33

[treo]

Sigsputnik, In the R33 gtst the fuel pump is located in the boot, if you open the boot act as though you are trying to access your battery an you will see to the right off the batt a small flat piece of metal held down by 4 screws underneath that is your fuel pump located in the top of yuor fuel tank. If you turn your keys on to ignition but dont start it, it will make it easier to here what it sounds like should be able to here it at the petrol flap if the cars not running or even in the drivers seat if you listen carefully.

The way i did it was stick my head right in the boot, so i could still here it operating when the car was running, then while the car was actually idling i could here the fuel pump go of then a second later the car would stall and as it stall yuo could here the pump switching back on. Weird loosing power to the fuel pump for a second, so far know one but BHDave can really tell me anything about the fuel pump speed control circuit and ive got the standard pump so the voltage shouldnt be a problem

[Cubes]

I had a dodgy AFM wire connection at the ecu plug.

That was causing exactly what you describe.

Luckly I had a PFC plugged in so I was able to watch the AFM signal drop to 0v.

[BHDave]

Heres the pinout diagram for the rb25 ecu, it has a few holes in it but shows you which pin is which. Combined with the wiring diagram it tells you everything you need to know, except where the unit is mounted. Best guess is it will be in the drivers side rear quater panel behind the boot trim.

I cant upload the wiring diagram as the file is too big but you can find it here http://www.meggala.com/rb25detenglish.html

Basically, pin 104 is the one that controls the fuel pump speed. By chopping this wire (as mentioned above) it will stop the pump trying to drop it's speed.

You may find now that the tps isn't reading 0V after you cleaned the TB and so the ecu thinks you have your foot on the throttle and so doesn't drop the pump speed.

On the wiring diagram down the bottom, just left of centre you will see the dropping resistor with RB25DET and a bit of jap next to it in brackets. Looks to be connected via a 2 pin plug, same as in an r32, where the resistor hides i have no idea.

Alternately you should be able to disconnect the control unit (4 pin plug) rather than chop the wire.

good luck

[BHDave]

http://www.skylinesaustralia.com/photopost...&cat=500&page=1

Heres a shot of my r32 engine bay with rb25. Top right next to the turbo you can see the dropping resistor. I know the r33 doesn't have it here though as i had to wire my r32 one into my rb25 engine loom.

[predator]

Are we talking about that dirty big silver square can thing ?? I have always wondered what that was for ..

There is a fair bit of info on diagnosing this particular area in Section EN-307 of the RB20DET engine manual, as well as some good block diagrams.

[BHDave]

yep

[sigsputnik]

ta for that, treo.

might interest you to know that i've had it with my car doing this so i'm 'taking it somewhere' tomorrow for them to check it out. will report back.

[treo]

Thanks BHDave, il have a good look at it when ive had a proper look at the diaghram. And aslo the only thing i can see thats silver in the back left near the turbo is the wiper motor, and i know thats what you mean but cheers anyways thanks heaps

[cav]

had a similar thing happen to my 33 it would start but not run after saying every swear word i know (and that is a lot) i found a blown fuse caused by the o2 sensor shorting out. so check ya fuses. hope it helps.

[BHDave]

Thanks BHDave, il have a good look at it when ive had a proper look at the diaghram. And aslo the only thing i can see thats silver in the back left near the turbo is the wiper motor, and i know thats what you mean but cheers anyways thanks heaps

theres a little box looking thing below the wiper motor mounted to the back of the strut tower. It may be a bit dirty

[sigsputnik]

my 32 is back from the mechanics - it stalled about 14 times on the way there, turning a 15 min trip into a 25 min trip.

he found two things:

- turbo inlet leaky

- AFM fuct

replaced the AFM and fixed the turbo inlet and it's fine. no jerkiness or stalling. idles just fine now.

i have the old afm here and may dismantle it to check the circuit board.

[treo]

sigputnik, your turbo inlet leaky, what was there fix just tightened it up or something. That seems pretty wierd to me however if there was a big airleak it would make sense to why you trip took so long

cav, i check all my fuses ages ago they are all fine. Cant believe that was making your car stall, mine runs ok with out it even plugged in

BHDave, what i ment to say before was i know the wiper motor was not what you ment but thats all i could really see, i got a better idea off what you mean now though. I have a good look for it on the R33 to help kill my curiousity. cheers

[sigsputnik]

treo that's a good point about the inlet - not sure if it was tightened or just replaced the gasket...but mostly it was the AFM.

[treo]

good to see your car is fix, mine seems to be running ok right now. however if done nothing and it seems to idle, i havent driven it any further than a couple times around the block though since i walk to work. My afm is all ok, so i got know dramas there and if i do i got a spare i had on a couple weeks ago.

[knore]

No more dramas for me

Running perfect now, think it just needed some running in, was sitting for 2 months

[BH_SLO32]

Treo,

I had to fault find what I believe is the same problem on my sisters R33 about a 2 years ago. The car would start ok but once it dropped to idle it would stall after about 30s. Turns out when the idle drops sufficiently to activate the idle contacts (associated with TPS but not an ECU input or output) the fuel pump idle speed ciruit takes over and adjusts pump speed. In my sisters case the resistor pack mounted on the inside face of the left boot kickpanel (where the jack is usually kept) had been disconnected thus failing to complete the fuel pump circuit and causing the fuel pump to switch off. The car would run for 30s thanks to the residual fuel pressure in the fuel rail.

If you have the problem again this is good place to start. Make sure you haven't got a faulty connection at this point.

Cheers

[treo]

BH_SLO32

Cheers its started doing the problem again, with my head in the boot i can here the fuel pump go off for a second the the car runs for about 5 10 seconds.

I know exactly the tihing your talking about in the lh inner quarter. About a month ago a new ariel was put into my car, maybe they have ****/ knocked some of the wiring. Ive seen the thing your talking about and its directly behind the ariel by memeory il go out and have a look right now

[treo]

Finally fix the problem!

thanks to BHDave and BH_SLO32 i finally fix the problem. There was a bad connection at the Fuel Pump Speed Control Circuit, i pulled it out and sure enough one of the wires was hardly in one of the plugs, fix it and now the cars running like a treat. Now you can here the fuel pump running constantly when you listen carefully for it. It no longer stalls and is running like it always had which is perfect

thanks for all your help

[BHDave]

Nice to hear. It always seems to be the odd ball controllers in these situations.......

Cheers

Dave

[sigsputnik]

that's great treo - i was real happy when mine came back to life. like a new car!