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Cold Start Again. Continuation Of Previous Posts

WogsRus

By WogsRus,
in Engines & Forced Induction

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WogsRus Veteran

WogsRus

Posted
Posted

In relation ot previous post

http://www.skylinesaustralia.com/forums/in...57857&st=20

Here it goes again.

So basically, lately, it seems like the car in the morning simply does noo want to start, it coughs and so forht and carries on for 5 seconds, then fine, smooth as silk idle nothing. Almost like it only runs on 4 cylinders first and then all 6 come into line.

It only does this if it has been standing overnight, but lately also during the day. Once hot or anything no issues.

So so far i have done the following.

-New plugs, All good.

-Checked compression, still all 150psi eaven.

-Checked for vacume leaks, but vacume appears to be as per before, still to do more searching.

-AAC valve cleaned, and rechecked, and appears to work correctly.

-Redline fuel injector cleaner, special stuff

-Checked for head gasket, and all good.

-Put a new ECU temp sensor in, no good

-rechecked timming, and still as per before.

-cleaned air filter

-Fuel pressure and floww correct

-Spark plugs all look even and nicely coloured.

-Can was tuned 4 weeks ago, this started 2 weeks after.

Still to check AFM and fuel filter, but filter was redone 5k ago.

What i did was to reset the computer, drained all the fuel out of injectors, oped all the air bleed vents, and then restarted it the next morrning, and it still did it.

If i turn off the ecu temp sensor, it is fine, if i disconnec the AFM it is fine.

I have not checked Consults yet.

What i need to know is, how do i check the Cold start Valve and the FAST IDLE VALVE? Apparantly the skyline has these.

I am at a losssss???????

HELP.

infamous_t Veteran

infamous_t

Posted
Posted

My R32 GTR does the same, on mine I don't think its really that bad.

I put it down to old(stock) coil packs on mine, that and maybe the cold weight of the oil being to thick?

Otherwise give a respectable tuning shop a call, won't hurt to ask.

Murry33 Experienced

Murry33

Posted
Posted

Have a a similar problem on mine, the cold start valve was adjusted to it would rev a little higher when started, which seems to help a bit. however i'd check out your afm and clean it thoroughly with "start ya bastard" or somethin similar, could just be dirty? but you have gone through most of the main things, so you must be close!

Cubes Grand Master

Cubes

Posted
Posted

I noticed with my PFC if the load points 4-8 @ 400rpm were leaned out it would cause this stumble.

Richening them up rectified the problem OR another way around it was to dial in more injector cranking time (ms) at the relevant 'stumble' engine temperature which for mine is ~10-20degree's.

Have you tried turning off the SAFC to see if it still does it?

Cubes Grand Master

Cubes

Posted
Posted

Mine always had a hard stumble start with the stock ecu.

PowerFC allowed me to tune it out so to speak.

I think there's definitely a problem underneath that is shared by both the R32 and R33's.

Just what is it? In my instance I have worked around it but really its just a patch up.

I'll be a little more clear. :P

Stock ecu.. Hard start stumble. Occasionally it would start nicely.

PowerFC Untuned.. A little stumble but no where near as bad as the stock ecu.

PowerFC tuned.. Hard start stumble on par witht he stock ecu. (noticed load points 4-5 @400rpm were leaned out, richening up these load points reduces the stumble)

PowerFC tuned but with my fiddling.. Cranking time increased to around 35ms.. Perfect start no stumble just vrooom. :P

From what I've seen it appears it doesn't get enough fuel. Pushing in more via the cold start cranking time sorts the stumble.

Rekin Grand Master

Rekin

Posted
Posted
nope not yet, the thing is it never use to do it, it just progresivly got worse. like something is not working correctly, but not sure what.

same here,

When my car came fresh off the boat, it started on colds no worries and was perfect.

Then after the first couple of weeks it started to struggle and it pretty much got worse and now happens every morning.

I wonder if the r32's in Japan have the same problem?

I also heard that if you leave your car untouched for 2-3 days it will start much easier than when you start it the next morning. Another rumor i've come across :(

nick81xd Community Regular

nick81xd

Posted
Posted

might wanna check the battery voltage on start up and idle charge and reving around 3500rpm could be not enough charge getting to battery

my 32 used to occasionally have a start problem i ran a 125amp cable to the battery(in the boot) and it has been good every since

voltage should be around 10-11.5 on start, 13.5-14.8 on idle and around a lilbit more on reving

WogsRus Veteran

WogsRus

Posted
  • Author
Posted

it has the stock fuel pressure reg and and aftermarket one. However the reg has beenon there for 6 months with no warries, it has always worked fine. I am not sure about the priming, but tyhe fuel priming sounds thesame as it has always done.

HOWEVER, this morning the problem has seamed to iron itself out, no issues what so ever, so who knows, will see how the car goes.

ONE more thing, i notice that my car vacume is about 1-2 mm HG lower then before. I have a SPARCO guage, and did a test, and the pressure line, when you put pressure in it, doesn't hold pressure. SO basically if i pressure rise it, it bleeds off to zero slowely. So i redid the lines, and still does it. I can't hear a hiss, but was wondering if they are suppose to do that?

I don't think i have a leak, but need to check.

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