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Cold Start Engine Prob

Andyn

By Andyn,
in General Maintenance

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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.

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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...

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