Jump to content
SAU Community

Cold Start Engine Prob

Andyn

By Andyn,
in General Maintenance

 Share

Recommended Posts

NewKleer Mentor

NewKleer

Posted
Posted

uve got a consult interface right?

datalog from as soon as u start car and post here.

does it make a difference if u allow fuel pump to prime longer (leave car on ign on/reds for a few seconds before cranking)?

and do what i said in previous post

Andyn Community Regular

Andyn

Posted
  • Author
Posted

No I don't have a consult interface.

I have reset the ecu and let it go on diagnostic mode, but deciphering the beep codes is difficult.

I tried going to Nissan and their interface supposedly doesn't work with 'imports'.

Wouldnt mind getting my hands on an interface and seeing the log...

UPDATE: Just as an update though - a few days after I cleaned the AAC valve I have noticed the idling has improved. It is sitting around the 1K mark now as opposed to 1.5k.

The only issue now is starting it when cold (it still needs a bit of throttle to get going). I suspect this to be a leak somewhere. Havent had the chance to investigate further.

If anyone has had similar issues and has fixed it feel free to post ur experiences.

  • 2 weeks later...
  • 1 month later...
  • 10 months later...
Bendar Enthusiast

Bendar

Posted
Posted
Bump, any more ideas? I need to get this sorted...

Dragging up an old thread here but I have had the same issue for about 4 years, when I bought the car it was fine then one day it was just really difficult to start. I had the fuel pump checked, AAC valve, Temp sensor, changed ECU's, injectors cleaned, even had a modfied plenum put on there for a while. I'm going back to the thought that it may be my injectors, I have a feeling that they may be leaking from the body of the injector. If it was say the AFM or serious issue with the fuel pump then I would be experiencing issues when the engine is on load or when boost comes on. I have also noticed ever since this issue arose that my fuel economy has gotten really poor, 350km to a tank. The only mods I have are a pod, 3" exhaust and FMIC, so I dont see how that could kill the economy.

R33silverS2 Mentor

R33silverS2

Posted
Posted

my car also struggles to start when cold ever since i changed from the stock fuel pump to a bosch intank item. Even with considerable priming (ignition on for about 5 - 6 seconds) the car cranks and struggles. Once it doesn that it turns over fine. I ve had the fuel pump taken oout and tested and it flows fine. The instal is also fine so i to am scratching my head at this. Basically whats happening is when the car is switched off the fuel lines lose preesure with after market pumps and the fuel drains away. Problem is it doesn't seem to pick up enough even if you prime it to be able to start first go. IT starts fine the second time you go to start it as it has built up some pressure from the first time. I might see if a one way valve of some description will help this problem if i fit it to the fuel line or something.

smiddidR32 Collaborator

smiddidR32

Posted
Posted

funny you started this topic i was about put the same thing up im having the same problem with my 32 i just got it back from graeme west two weeks ago where the problem was ment to be fixed but is still playing up, good to see some different pointers!! mind you its going back in to West this week cheers guys :P

Jmaac Proficient

Jmaac

Posted
Posted

This might be a bit off but could your battery be dying or too small as it seems to only be a problem when your cars starting? If your battery cant hold enough charge/supply enough current during the cranking process this would result in the poor/reduced fuel pressure delivery during intitial stages of priming the fuel lines etc.

Check the voltage over the fuel pump when cranking, the fuel pressure and go from there

Sheriff Wan Proficient

Sheriff Wan

Posted
Posted

All good thought lads,

I have a 32 with the same issues however I can count the fuel pump out as I have a brand new one and AFM :)

Something that hasnt been raised yet is the cold start idle valve....

Just a question:

When your cars eventually start do they idle up around 1.5-2k for a minute or so or do they go straight to the 1k or there abouts?

The cold start thing is a mechanism that works like a line that gets blocked once the car is warm. When the car is cold the line is open to give more revs to start the car... when the car is warm the line closes.

When you start the car it should idle high for a little while... when I first bought my car the idle was at about 2k constatntly and it was due to the cold start valve being constantly open making the car think it had just started all the time. When this item is faulty or old as most are the heat sensor no longer works and the valve does not close and bring the idle down. It goes both ways when they are buggered they can be open (high idle all the time) or closed (normal idle all the time causing hard cold starts).

My suggestion is that the cold start thing is constantly closed making the car think it is constantly warm already... and therefore not giving the intial revs to bring the car to life so to speak.

The cold start is located (looking at the car head on) on the left hand side of the engine bay below the intake manifold.

Any thoughts...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Watermouse
      Stock rb25det neo questions

      By Watermouse · Posted

      GTSBoy on your suggestion on another thread I had a look at those injectors and ended up getting them because of the quality.  Got the expensive ones.  
    • PranK
      Happy New Year!

      By PranK · Posted

      Happy new year!
    • eli995
      R32 gtr hood latch support/lock part number search

      By eli995 · Posted

      Hey guys been looking everywhere to try and find the correct gtr hood latch support part number but only found the first half and when I search with that number it sends me to an r34. The first part I found was 62515. If anyone could help me with the rest then I’d really appreciate it. Or if there’s some alternative hood latch support that would work even better cause I can’t find any for sale. (Searched on upgarage, partsouq,buyee,rhdjapan) 
    • GTSBoy
      Stock rb25det neo questions

      By GTSBoy · Posted

      If you've only done the upper control arms on the rear, AND you have changed their length (by more than about 1mm) to set the camber you want, then you will definitely need/want to install traction arms also. Adjusting the camber arms on their own WILL introduce bump steer and make the car unpleasant to drive. Most owners have no idea that their car could behave infinitely better than what they put up with. I'm not entirely sure what the Stageas need, but I am thinking that unless you have massive front spring rates and pretty soft rear springs, you have waaaay too much rear bar. Oversteer city, in my estimation. Combined with possible excessive bump steer from maladjusted arms, that could be a recipe for nastiness. ATR43SS2 is not a highflow. It is an outright replacement turbo. It's a little bit bigger than the largest highflow profile that Tao does. Probably a solid 300rwkW turbo where the bigger highflows will be about 30-40rwkW less. Nevertheless, we're only talking about ~300 rwkW, which is well within the abilities of the stock ECu to run with a Nistune on board. I would do so without hesitation - and I will be doing so when I get my finger out and actually get the injectors and AFM installed. But, if you would prefer to drop a whole lot more money on the ECU side, then I suspect you're looking at Haltech. The Haltech fanbois here will all spout on about all the available engine protection you can have, that you can't have with the Nistune option. And they're right. But it doesn't really come for free either. You will spend more money on extra sensors and the like, plus the work to install them. If the engine was built and therefore represented a big investment to protect, then I'd say definitely do it. If you view the current (and forever into the future) shortage of replacement engines as something to prompt similar protection, then also, do it. If you see a destroyed RB25 as an opportunity to put in a Mercedes or other V12 (like I kinda do)... then your perception of the risk/reward might differ. These are good injectors. You can also get a "better" set of the same with more flow matching, for more $$. 1000cc is where you will want to be. You will need an R35 AFM and adapter tube if you want to stay with Nistuned stock ECU. Otherwise, if going Haltech, you can ignore. As for intercooler. Just about anything will do. You're only talking about ~300rwkW. Just put a big core in there. Be aware that return flows do add significant pressure drop and will cost power and will make the turbo work harder to achieve the same goals. If you can manage a proper crossflow, do it. I'm keeping my very good return flow because I'm only expecting to be in the ~250rwkW range, and will live with whatever outcome I get.
    • Millerman
      Jdm toll card reader talky box

      By Millerman · Posted

      I have a heap that i have collected if you want some authentic ones still. Pm me if your interested!
×
×
  • Create New...