my whole bad situation....

[josephg15]

any opinions welcome....so my car bucks right before i hit boost, and sometimes out of nowhere, i check my tps (good), i check my maf beswitching it out with a friends (good), i checked the timing (good), changed out my coil packs with a friend (good), i changed my sparkl plugs with (ngk v-power bkr6E-11), i put injector cleaner in the gas tank. ..........yesterday my car wouldn't start, i poped open the fuse box and tapped on the egi relay, and egi pump relay, and the car started...any ideas...and i took off the piping to my turbo and throughout the intake piping there was oil residue along with the turbine...will a blown turbo cause this bucking...but when i test drive it some times the idle will jump up and down...please i need all the help i can get...thanks

[Morph]

I'm sure that you have put this in other post but what is your current setup?? Oh btw the spark plugs that i run are bkr6es. im sure thats what you ment just fyi.
Modified by Morph at 4:00 PM 9/3/2006

[Luke]

Have you check over really well for boost/vacuum leaks? It could also be fuel, did you have a new 300ZX fuel filter installed when you swapped? Are you still running the stock fuel pump? Are there any other symptoms besides bucking like exhaust popping? Does it just fall on it's face with no power when you hit boost or does it start breaking up?

A little oil blow-by is normal since the valve cover vent is hooked to your intake. My intercooler piping and turbo compressor outlet got pretty oily until i installed a catch can in there.

[Morph]

Is the ecu throwing out any codes???

[josephg15]

no the plugs that i put in are NGK Bkr6e-11 stock# 2756, i changed out my fuel filter and i have the walbro fuel pump (255) my ecu is throwing a code 55...which i believe means no malfunction...everything is ok. what is the best way to check for a vaccum leak....do you think my turbo is bad? ...................ok so pretend im driving...when i cruise the car feels normal...when i punch it, its ok till i come up to about 3700rpm- 4000rpm...it lags for a second and the catches up, and now the car idles at 1500rpm- 1700rpm...this is killing me. i think there might be way too much oil in my turbine thats why i think its blown, but i want to make sure before i spend money for a nother one.

[S13240]

What are your plugs gapped at? Should be about .35 for stock and decrease the gap as you up the boost.

Sounds almost like a boost/vacuum leak. Got any pictures of your engine bay?

[josephg15]

ill post some pics of the engine bay tomorrow...its late right now...please check back tomorrow afternoon.thanks

[Morph]

This is virus77 diy boost leak detector heres the link to the pagehttp://forums.nicoclub.com/zerothread?id=113785

This is something that is pretty handy and costs a few bucks, eveyone should make one. Some people requested it on another thread so I'm posting here so others can see aswell. Here it goes.

Yours will look different but will do the same thing.



Parts you need:

-The coupler you use to connect your intake pipe/mafs to your compressor intake. -a pvc end cap from home depot that fits snugly into your coupler. (so its the same size as your compressor inlet on your turbo)-simple hose clamps to hold things together.-some form of air compressor (personal, shop compressor, foot pump, etc...) Further testing showed you need a pretty decent pump to make this effective, shop pump or home air compressor would be best -a fitting to attach your air compressor of choice to pvc endcap (refer to pictures)

Here are the pics:

The end cap needs to have a hold drilled in it so your fitting can attach to it. This is where you will presurize the system from.



you insert the end cap into your silicon/rubber coupler and clamp it down (I had that extra silicone bend for my new maf piping I was gonna make so im using that for the time being)

The other side of the contraption gets attached to your turbos compressor intake (where the air filter/mafs coupler would normally go).

if you have a bottom mount setup and its difficult to get to the turbos intake you can also pressurize the system from after the mafs and use your cars intake piping as an extension to the turbos intake. However when doing this make sure the any line going to the intake are plugged. For instance if you have a valve cover breather line/ PCV / catch tank going to the intake pipe it needs to be plugged or else you are going to pressurize your valvecover, crankcase, etc and it wont work. Although I did find a valve cover gasket leak like this



Then you attach your choice of air compressor to the fitting on the end cap side and you pressurize the system. Check your boost gauge and presurize the system up to like 15 psi or whatever you would run to see if anything pops off.

Final product



Thats pretty much it. Obviously the motor is off while you do this so If you have the slightest leak it will make a loud noise and you will find it, also if your intercooler connections are leaking it will leak and you will find those aswell. Depending on the size of your leaks you might not be even to pressurize over a few psi, so just keep fixing leaks till you hear no noise. Let me know if I left something out or if you have any questions.

Modified by virus77 at 5:18 PM 1/31/2006

Modified by virus77 at 5:24 PM 1/31/2006

Modified by virus77 at 5:24 PM 1/31/2006