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Cold Start Fluffiiee. Update

WogsRus

By WogsRus,
in Engines & Forced Induction

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WogsRus Veteran

WogsRus

Posted
Posted

HI all, well I have had these ongoing Cold Start issues with My S1.5 R33 GTST.

http://www.skylinesaustralia.com/forums/in...=160180&hl=

http://www.skylinesaustralia.com/forums/in...=157857&hl=

Basically, when I go to start the car when it is below 18 Deg C, the car splatters, sounds like it’s a bit flooded, revs at 300 rpm, then coughs, splatters and is fine from there.

I have done many things, and over the weekend what I did was to turn the fuel pump off, and pressurize the fuel system with air, to remove all fuel, you will be surprised to hear that the car will run for 2 minutes on the fuel in the fuel rail alone.

So after ensuring that there was no fuel in the rail, or injectors, I was hoping to solve my problems of cold start, but figuring out that it’s a leaking fuel injector.

WELL, I reconnected the hoses, primed the lines and the car still started like crap.

So I figure it’s not the injectors, but can someone shed some light on if what I did could prove that it was not the injectors.

ALSO I got Nissan Consult but i can't seam to upload the log file as a txt. All I can see is that the O2 sensor keeps saying rich when starting up cold, which seams weird.

Can someone look over these files and see if there is something REALY obvious that is wrong.

Please help me, I am going out of my head.

ALSO, how much water/moisture, would I need in my engine to cause starting issues?

One this i did notice badly, is that while cranking the voltage drops to below 8 Volts, 7.1 to be exact, i presume this is not good. If somone hads a means of analising the datascan logs, let me know i will send the log to them, i can't seam to upload the .log files.

There is now also a squick in the car, like a vac leak, but it's not a vac leak, and as soon as i touch the throttle it disapears. I have checked for leaks, can't find any, could be a belt or something.

HELP.

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https://www.sau.com.au/forums/topic/162820-cold-start-fluffiiee-update/
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Cubes Grand Master

Cubes

Posted
Posted

Have you tried adjusting the IAC's cold start idle. There's a screw on it that allows you to apparently allow more air through when cold.

Mine stops spluttering if I push in more cranking injector time at 10degree's. From memory standard is 24ms, I pushed mine up to 35 and it starts instantly. But thats on a PFC. My stock ecu did the same but obviously not remaped so I wasn't able to test.

Its normal for the o2 sensor to read rich when cold. Since I put the new genuine o2 sensor in it reads 3.98v when I first start the car, then as it warms it quickly drops to 0.2-0.9 and begins cycling.

It can't help doing a vac/leak test. Grab a bit of exhaust pipe, weld a top on to it, 2 t-bolt clamps, either an aircompressor attachment screwed in to the top or drill a hole and use a tyre valve, remove the afm to compressor cover pipe and place the little tool you just made on to the front of the compressors inlet. Spin the motor over to TDC and compress the system to around 10psi. Soapy water and spray it looking for bubbles. :( You can also use a piece of fuel hose shoved in your ear to listen around the IAC and those hard to get to bits (inlet manifold etc)

WogsRus Veteran

WogsRus

Posted
  • Author
Posted

hay cubes, thanks, that is how i find leaks anyway, will have anothee look see tonight.

I have an SAFC II and a remaped computer, so no go on the cold start enrithcment change, but I THINK i have nailed it down, when cranking my VOLTAGE drops to 7.1 volts, THAT IS BAD i pressume.

I am goign to try another battery to see if that helps.

From some of teh genericl RB25DET logs i have, the lowes cranking voltage i have seen is 9.6V.

Cubes Grand Master

Cubes

Posted
Posted
So having a shit batery voltage drop is A BAD THING, i presume this can couse a whole lot of problems with igition coil charge times and so froth?

No idea... :S

I had a crapo battery that head a dead cell from new, that was dropping to 9v odd and was sluggish to spin the motor over when cold. But with the correct cranking time at that temp it would still start without a stumble.

  • 1 month later...
  • 3 weeks later...
MANWHORE Grand Master

MANWHORE

Posted
Posted

I reckon on my car, it's the cold start/aac/aircon valve. I have never cleaned them, and i'm gonna give em a go in the holidays. I know you've done all those, but can't hurt to try doing the ones on my car.

Strangely enough, mine hasn't been doing it either, and it's been crazily cold these past few weeks. so strange. I haven't changed anything.

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