91 240sx : Recent turbo install on KA. Idle and vaccum problems.

[MATT41178]

I have turbo charged and rebuilt my 91 240sx ka24de

First problem is my vacum is low and I cant find a leak any where.

Second is my idol is eratic (from 750 to 900) and it dies at stop lights.

Third I am not sure if I am setting my boost contoller right, I have a greddy profec b-2
Modified by MATT41178 at 10:12 AM 9/18/2005

[NISTECH]

Try pinching off you fresh air PCV line to see if it improves your idle. If it does you may have a stuck open PCV valve.

Have you checked your intercooler for leaks? try spraying some carb clean around your intake piping and on the intercooler see if your idle jumps when you do. When this happens you found the area of the leak.

I dont know much about the boost controller. You may be better asking or searching in the KA-t forum for that.

[MATT41178]

Ok I just replaced my PCV valve and now I have two more problems,and that PCV valve sucked!

When accellerating at half throttle my engine stumbbles.

and when I stop at light either the idol will go really low or it will die.

And now afer it dies it wont start right back up.

Please help I am about spend alot of money and have some tuner shop do it but Idont really trust any of them in my area.

[NISTECH]

Did you ever try pinching the fresh air like I metentioned? Before you bought and installed a new PCV valve.

[MATT41178]

No I couldnt reach the hose it was to far for down to reach and I figure I needed a new one any way.

also when I first start up my gauges dont start working up for about a minute.
Modified by MATT41178 at 12:42 AM 9/24/2005

[NISTECH]

The PCV fresh air hose is the one at the front corner of your valve cover going to your intake tube.

I assume you might have digital gauges insted of analog?

[MATT41178]

Im sorry I did try piching that hose and got no improvement, my idol is much better now but it stil goes to low when stopping and dies and wont start back up.

and I do have analog gauges.

[Florida240sx]

How is your BOV run? Coming off boost I have to "blip" the throttle so my car doesn't stall. I'm running crappy wires and open exhaust and atmospheric bov. ALso I gapped my plugs to small.However it's fine as long as I leave the fan on. You say your car is breakign up?You mean starts to sputter? What is your plug gap? When I replaced my plug i had a 64 gap. stock is 44 and turbo should be 28-36.So maybe your car if flooding out and that's why it won't crank. You smell fuel? got AIM?

[MATT41178]

I have a RFL BOV to atmosphere and I have new NGK iridiums and new wires gap is at .028

but yes I do smell gas after it dies I am running a JWT ecu and msd 50lb injectors

[Florida240sx]

Well being your bov is atmosphere you ar goign to have that problem of it trying to die.I think your gap may be too small. JWT runs a bit rich. and could be flooding your motor. My gap is 31 and i have a bit of idle issue.i cna imagine being at 28 how much worse it would be. Try takign your plugs up to 32 and see if any improvement. Do you have a wideband? Are the ngk spark plugs as well?(they work best with nissans)

[MATT41178]

yes my plugs and wires are NGK I found out on this forum those are best for nissan so thats what I got and no I dont have a wide band.

I will try changing my gap right now and post results.

also I am using BKR6EIX plugs.

Thanks
Modified by MATT41178 at 2:17 PM 9/24/2005

[MATT41178]

changed gap to .035 runs alot better but it still wants to die when I stop.

Istill have some hesitation at half throttle from 2k to 35k but after that its fine.

[NISTECH]

sounds like you may have an issue with your IACV. Try running a seafoam treatment if your havent yet.

[MATT41178]

I have done some searching about seafoam and I read that you cant clean your iacv with it.

How would I use it to clean IACV?

[NISTECH]

The reason they say you cant use it is your feeding it through a vaccum line on the manifold rather then feeding it through your intake tube. There is a 1 inch hose coming off your intake tube [not the one going to the valve cover] If you send some of that or even carb clean down that tube it will at least partially clean some of the carbon out of the valve.

[NISTECH]

also do it once the car reaches full operating temp so it wont get sucked through the aux air regulator. Once the car is warmed up the aux air reggulator will be closed.

[MATT41178]

Ok I tried spraying carb cleaner down that tube as soon as I pulled it of my car died and It wouldnt start back up.(as usual every time it dies it wont start back up for a while!) I still sprayed some in it to see if it works.

[MATT41178]

also there was alot of air being sucked through that hose.

[NISTECH]

umm oops guess I forgot to tell you to spray it down there when the car wasent running. Then you hook it back up and start the car. Sorry. That is the air source for the engine. When you disconnected it the air flow meter no loinger saw air getting into the engine and cut the fuel to it. Again sorry bout that. When you go to restart it try holding the throttle open to see if it will fire up.

[MATT41178]

No problem.

I have tried every thing when it dies and it just turns over and wont start unless I let it sit for about three or four hours, It seems like it has vapor lock or it is flooding out.

I will try spraying it in before I start it

[NISTECH]

Its time to break out some test equipment. hook up a fuel gauge and see if you are getting fuel pressure when it wont start. USE A GAUGE, do not just feel the line to see if its getting hard. That really tells you nothing. If that checks out see if your getting spark. Your doing those tests when it wont start.

[MATT41178]

Ok

I know I have fuel, I have a gauge on my FPR today when I stalled it I pulled the fuel pump fuse and cranked it untill It started and let it die then put the fuse back in and it started right back up.

so I think its flooding some how, the carb cleanier did not help.

do you think I need to replace my IACV?

[MATT41178]

bump!

[NISTECH]

What was your fuel pressure when it would not start?

[MATT41178]

At idol, psi is at 36, with key on it is 30.

[NISTECH]

#0 is too low with just the key in the on position. It should initially hit about 40 when you turn the key from off to on and not drop more then 10 pounds with in 10 secs

[MATT41178]

when I first turn the key on it is right at 40 untill the fuel pump stops,as soon as the fuel pump stops it goes to 36 and stays there for around 10 seconds.

[NISTECH]

Is this when it wont start?

[MATT41178]

this is all the time I have checked it when it wont start its the same.

[NISTECH]

next time it wont start hold your foot to the floor and crank the hell out of it, do not lift your foot till it starts to sputter like it is going to start. Even then gradually bring it back to idle or just off idle position. Dont let the engine redline though back out if it start to rev up. Crank the car 10 seconds each time. Let it rest for 15 secs in between cranks. After 2 or 3 times it should start if its a flooding condition. If that works look at your coolant temp connector and see if you got corrosion in it.