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Hey Ska,

The R33 has NO map sensor. The small hose comming from the plenum and plugging into a sensor is purely for the boost gauge on the dash. No input from it goes to the ECU. Your relatively lucky finding such a simple solution to your problem :D

:D look there is a new smiley.... i'm gonna flog this one! I didn't know that the map sensor is for the gauge only, where did get that info?

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...straight from the JPNZ R33 engine service manual electrical schematics. There is NO connection to the ECU from this device. There is an AFM and a TPS so there is no need for an additional MAP device for engine control. Also the PowerFC hand control has no diagnostic readout for the device as it is not part of the ECU system, whereas both AFM and TPS do.

The only way this device can cause engine running issues is if the tube splits, which the do eventually at the connection to the plenum. The resultant vacuum leak can cause issues...

That is what i had worked out myself, It's always good to have it confirmed!

The weeny hose from the plenum was used to run my boost controller and the result was numerous repairs until i replaced the entire hose with newer rubber that would not split every week or so!

:D phantom!

i had that stalling problem for ages, like driving in slow traffic stopping and starting every time i of the go pedal it would stall, embarssing at drive through's to. today my friendly mechanic replaced the oxygen sensor and cleaned the air flow meter. my stalling has gone , and the car runs like its brand new.

  • 2 weeks later...

Does anybody know where is/how to service the cold start idle valve (or whatever is used for cold start)

I replaced the mesh on the back of my AFM (on advice from a Japanese performance mechanic), as he said this will be causing the idle problems I was having (air reverting off the compressor wheel) - it worked very well, on my car and another guys (who both had the mesh removed from the AFM) - the car has never idled so well. But still there is one niggling little anomoly that I would like to sort.

The idle is almost perfect, except when the engine is warming up, and is sitting around 78-79 deg C, so I am thinking this last piece of the puzzle has to be to do with the valve that bleeds air on cold start.

Anybody got any ideas?

Cheers

The cold start valve is in a pain in the ass position under the intake plenum. It can be removed if you have the right size tools. It can also be pulled apart and cleaned. A whole lot of crap collects here over the years. I had mine siezed shut and thus provided no cold start. There is also an adjusting screw, and you can physically bend the internal spring to get the characteristics required. Once apart you'll quickly understand how it works. I remember doing adjustments, running it, the taking it off, putting it in the freezer, adjusting and trying again. It picks up heat off the plenum assembly, but it also has an internal heater element which gives a time based function. The ambient heat then overrides the operation in warm engine conditions. Hope that helps some...

Now we know having a atmo vent BOV can cause the stalling. But would say having NO BOV do the same thing? My stock BOV has a metal plate compleatly covering the BOV hole. I have an after market fuel pump, so Im guessing its not the wiring for that, we turned up the idle to where it should be that helped, but didnt solve the problem.

Im going to be replacing the BOV with a quality plumb back soon, but I just want to know if it should be sooner rather than later. Or if even in the mean time I should remove the plate if only to stop the stalling.

on some cars the reversion steve was talking about earlier especially WITHOUT BOTH mesh pieces on AFM can be amplified by no bov, but it is rare. your tps voltage after adjusting idle up. i dont use a bov to help with throttle response, not between gears but mid corner with rapid on off throttle the bov causes soggy response. i no longer have a prob after getting tps and afm mesh shite sorted. check it i think it is .5 -.6 pm steve he knows his skyline shite inside out.

I'm completely lost in all of this...

This problem is definately an issue with many different things.

My car does this but doesn't stall. It just bounces when its idling for more then 2 minutes.

I've been told it's usually a vacumn leak in one of the pipes in your engine bay...

But shit i dunno thats just my 2 cents.

  • 1 month later...

Recently I have been getting stalling issues and after reading over this thread it appears I can be added to the list. Some days my car is perfect and then other days it will stall 3 or 5 times in the space of a dozen sets of lights. I originally thought it was bad fuel (I always go to the same petrol station to fill up with BP98) so I started using Optimax again and that didn't make any difference. My car has always has a superb idle by only moving around 30rpm when the car is warm however these stalling issues have been pissing me off majorly.

I thought i'd adjust the idle screw just for this weekend until I can get a chance to go back to my mechanic whom installed my Bosch 040 to do the ground wire theory however I can't even get to the idle screw because I don't have the right tools and the strut bar is in the way grrr.

Did anyone manage to answer which colour the ground wire is as I can't recall anyone mentioning it?

Benm, how'd you go with your mechanic? ive had this problem for a long while, but my car doesn't idle at all... not just every now and then.... very annoying!

had a look into the fuel pump connections.. there are 2 plugs

one with 2 wires, and one with 3 wires...

my guess that the 3 wire plug is for the fuel level sender attached to the fuel pump assembly +ve -ve and sender wire..

if thats right then the 2 wire plug is the one we need and i would say it is the black wire! havent looked into it too much more but i will get the multimeter out tomorrow and check it out, and mod it to see!

Hi Chris,

I have my car booked in at an auto electrician on Saturday morning (in Kingswood opposite the Cemetary next to the mechanic with the big blue fence). He fixed my driver-side electric window at the beginning of the year and the mechanic next to him installed my Bosch 040 about the same time so between the 2 I don't think they will have any issues finding the correct wire. I'm getting a kill switch installed at the same time, should cost me about $100 all up.

If you work out which wire it is let me know eh?

I tried adjusting the idle screw as a temporary fix only to realise it has a bolt to stop it from moving itself (I didn't have the right tool / time to adjust the bolt then the screw), But have noticed that my car is revving higher when putting the foot on the clutch so not sure what is up their because the screw can't move without the bolt being adjusted first.

Edit: You can come down to the electricians whilst im there if you wish or I will just let you know of the outcome afterwards.

as an addition....

i know that i have a cracked exhaust manifold atm, which is pretty bad, providing alotta noise under load.

now i do have an AFR meter installed that shows it go lean on idle and stall.. now this could be caused by the exhaust manifold whixh shows the 02 sensor a wrong figure causing the computer to do something and cause the stall... wont know til i get it fixed but any comments on it would be good !!!!!

Ben,

i'll be at Oran Park on sat, so if i dont get it done tomorrow i'll contact you and see. Ive been to that auto elec before to get my air con regassed and rewired and check out why my car had huge load on the battery.. good blokes but i did most of the work as i had to get the car fixed asap..

strange about your idle screw, mine doesn't have anything stopping it from being adjusted!!

My mates racing his Formula Ford, there should be the HQ's, Improved Production (raceworx should be there if everythings fixed) formula Vee and some historics... allways a good weekend! sometimes there formula 4000 there too have to wait and see!

it's sat and sun, what else is on?

  • 2 weeks later...

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