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R34 Hard To Start/not Starting.

JiN_MaN

By JiN_MaN,
in General Maintenance

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JiN_MaN Veteran

JiN_MaN

Posted
Posted

R34 Neo Turbo

Car wont start now unless I give it a small bit of 'Start ya Bastard' then it fires 1st go and idles fine.

It has been taking longer and longer to start over the last month and today it wouldnt start at all without some help. Car was having this problem before, but I have just changed, turbo, injectors, ECU, coilpacks x2.

I do get code 21, ignition, but that was when I had a missfire. I changed coilpacks and it now runs fine when started. I haven't rechecked to see if Im still getting code 21.

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Sinista32 Grand Master

Sinista32

Posted
Posted

Have you checked to see if you have any new codes? Link to codes

Just on the issue of hard starting

- Plugs fouled or incorrect gap

- Battery - Cranking power (no dead cells)

When you were changing the turbo, injectors and coilpacks - did you move/unplug the TPS, TCS etcetera ... have you reset the ECU since then and checked for new codes.

Maybe the quickest way to identify your issue/s.

JiN_MaN Veteran

JiN_MaN

Posted
  • Author
Posted

So bit of an update,

Changed spark plugs, no change.

Showing Code 55 (no faults)

I can restart the car if I have had it running within 30 seconds otherwise I have to give it another spray of start ya bastard.

Im starting to thing vacuum leak. I say this because if I give it a rev it drops to 500rpm after and then goes back to idle at 1000rpm. It doesnt catch the revs on the way back down, if that makes any sense.

Kinkstaah Grand Master

Kinkstaah

Posted
Posted

I had this once, after doing pretty much everything in this thread, and it turns out that it was caused by the ECU not giving any timing when starting the car.. even though once started it would run fine...

JiN_MaN Veteran

JiN_MaN

Posted
  • Author
Posted

I had this once, after doing pretty much everything in this thread, and it turns out that it was caused by the ECU not giving any timing when starting the car.. even though once started it would run fine...

Ive got a spare ECU ill change it and try again but I have just replaced the ECU. Had the problem before and after. Ill give the CAS a swap and AFM and after that im offically out of ideas.

Kinkstaah Grand Master

Kinkstaah

Posted
Posted

My ECU was fixed by the tuner who was like "uh oops" but there were plenty other issues at the time. ECU has since been changed and this was quite some time ago. I do recall the problem quite annoying at the time!

In my case it was a piggyback ECU sitting ontop of a normal ECU. You didnt mention what ECU you changed but I'd imagine no stock ecu would ever have a problem like this..

RB25DETC33 Community Regular

RB25DETC33

Posted
Posted (edited)

Checked all vac lines? Even under the charcoal canister, sometimes the vac hose coming out the bottom comes off. I had this happen on my 34. You can't see that its come off unless you specifically feel the underside of the canister.

Edited by RB25DETC33
  • 2 weeks later...
JiN_MaN Veteran

JiN_MaN

Posted
  • Author
Posted

So problem solved thanks to Jaustech.

The ECU gets start signal, and it has an inline fuse. The fuse had gone. Im not sure what the ECU does when it gets a start signal, possibly a bit more fuel to help kick it over im not sure.

To diagnose this you need to print off an ECU pinout diagram, find the 1 relating to starting and check to see if its getting a signal when cracking.

Now im not sure if the fuse is away from the normal fuse panels (drivers side engine bay/Drivers foot well) or not, but apparently that was the issue and it start like a dream now and runs great.

Moral of the story, check your fuses and if they are all good. Get the pinout for the ECU, find 1 relating to start signal, test.

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