R33 Rb25det 1.5 - Dramas

[Nissan Maaaart]

Hi there Guys,

It's been a while since i have posted a question and i have done some searching through the forums but i can't seem to find what i'm looking for.

Problem -

1995 Series 1.5 Skyline RB25DET

* Issues started with low idle - and engine stalling when cold (By the way it's an automatic) Engine would stall if any load was put on it.

* Investigated timing and all timing marks line up for 15Deg

* I've had fun by doing the following - re-Gapped sparkplugs; Got a 2nd hand CAS; Got a 2nd hand AFM; Brought new plugs

I've just been playing with the car today and managed to get it firing by itself but i had to hold my hand over the AFM to restrict the flow Engine was able to idle for 3-5secs before stalling again - I repeated the process and when firing took my hand off and died -

I'm thinking in my mind the following -=-

Either I have a break in the pipe work (Intake) but when i had my hand over the AFM the pipe was sucking in and i couldn't hear any other air. Or the AFM is cactus.

Does anyone have any other thoughts -

Regards,

Ashley Neal.

[Adriano]

Check trouble codes then

check fuel pressure

[Nissan Maaaart]

Check trouble codes then

check fuel pressure

The ECU did show me Code 55 - Everything OK -

The Fuel Pump is working - I disconnected the Feeder pipe and put into a bottle plenty of fuel went into the bottle - Is there a spec on how much presure should be there?

[Adriano]

Connect the bottle to the return hose, not the feed

[Adriano]

Fuel pressure should be about 45psi with the vac hose disconnected off the reg, but if you are getting fuel out the return then there is enough pressure to start it assuming the reg isnt stuffed

[GTScotT]

whats it like when its warm?

is it on a stock ecu?

if its always idling very low and is on a stock ecu, perhaps try to adjust the idle up a touch. theres also a mixture screw on the back of the ecu that you could fatten up a touch, that makes them run a little easier when their cold. But if you add fuel on base idle you will also want to up the idle screw.

GL

[Nissan Maaaart]

whats it like when its warm?

is it on a stock ecu?

if its always idling very low and is on a stock ecu, perhaps try to adjust the idle up a touch. theres also a mixture screw on the back of the ecu that you could fatten up a touch, that makes them run a little easier when their cold. But if you add fuel on base idle you will also want to up the idle screw.

GL

Hi mate,

The car seems to be racing when warm - sitting just shy of 1000rpm - when spec say's 650+/- has a slight sputter every now and again.

The ECU is a completely sealed unit with no trimpod for adjustment. I also checked for Dry-Solder in the AFM - and everything checks out there = ECU still giving Codee 55 = All Ok.

Edited June 13, 2010 by Nissan Maaaart

[lookingforboost]

check all hoses/ lines for boost leak and vac lines mine played up not as bad but it was a split vac line, then mabe have a look at your coilpacks next

[jjman]

id go for fuel pump.

They can throw up an array of symptoms but seem ok with prelim testing like you did.

Otherwise vacuum leak...

[Nissan Maaaart]

id go for fuel pump.

They can throw up an array of symptoms but seem ok with prelim testing like you did.

Otherwise vacuum leak...

Thanks mate, I've checked all the Intake piping and there is no apparent air leaks - does anyone know what type of presure should be coming from the rail --

I also did some further testing and with doing the following - blocking the Intake - and allowing a small vaccum of air into the AFM - the car would start with timing retarded - engine would fire on it's own for a moment - but if i removed my hand or made the vaccum less the engine would stall --

The suction from cranking felt quiet faint - can anyone comment on this?

Thanks.

[Nissan Maaaart]

.

[lookingforboost]

did you look at all the piping cooler etc? my freind had a problem with his for 3 weeks before finding a pin hole in the intercooler.

try changing the fuel filter as well my turbo pulsar wouldnt run and idle and it was a blocked fuel filter but it still primed etc

[ARTZ]

+1 for fuel filter...im assuming you've checked your air filter..

My mates car wasnt starting, and racing at idle, i blew out the air filter with a compressor and it ran great for another couple of days..cheap prick wouldnt spend 20$ on a new one

[rb27dets14]

I had the same problem on my rb25det s14 240sx it turned out to be a crack in bottom row of intercooler from bottoming it out

[Nissan Maaaart]

Righto - Still Not anywhere -

I've replaced - all clamps, enusres tight- checked Cooler for leaks - new fuel filter -

And still no go - does anyone know how much New AFM's are and where to get them -- as I got a price from a crowd and it seemed a little steep at 780$ex out of Melb.

Or does anyone on the Northside of Bris have a 3 pin (Pink Lable) AFM that is known good that i could try?

Thanks.

[Pal]

try clamp the fuel return fuel line after the regulator so it gives full fuel pump pressure to fuel rail and see if that makes a difference. if so then its the fuel regulator. only a idea

[geraus]

Try a diffrent AFM had a simular problem on a mates car, Go to a wreckers or something and you might be able to test it, also AAC valve is clean? check that as well. Do you also have a BOV? or is it stock standard?

Edited June 19, 2010 by geraus

[lookingforboost]

wreckers or on the forums here in the forsale section find a pink AFM for your car then try it let us know how you go with that.

AFM will cause a whole heap of problems

[paulr33]

just unplug the AFM and see if it idles

the engine will run with no AFM and should idle OK, but it wont drive very well and will rev cap at 2500RPM

if the AFM is the culprit when you unplug it, it should run to normal idle

if the AFM is NOT the culprit when you unplug it, the same problem will be present and it will stall

[Nissan Maaaart]

just unplug the AFM and see if it idles

the engine will run with no AFM and should idle OK, but it wont drive very well and will rev cap at 2500RPM

if the AFM is the culprit when you unplug it, it should run to normal idle

if the AFM is NOT the culprit when you unplug it, the same problem will be present and it will stall

Hi buddy,

The vehicle wont even start - or run enough to test this theory.

I'll try the fuel line thing shortly.