leaky injector?????

[UnderdogGN]

Hi guys, i have a question about my injectors. After i drive my car and turn it off, the fuel pressure will drop to 0 psi within 10 minutes. I have heard that is a symptom of a leaking injector. Do you think i should buy new injectors, or try to run some fuel system cleaner through there? Btw i have unknown non-stock injectors.
thanks in advance

 

[skostur79]

fuel injectors yes but you would need to check the fuel supply
to see if the pump is draining back too

understand how to check that?

 

[UnderdogGN]

not exactly sure how, do you mind explaining a little bit?
anyone have some bluetops for sale?
thanks

 

[skostur79]

ok u got 2 fuel line at the engine (driver frame rubber hoses to metal line)
take 2 needle nose vice grips cut a piece of 3/8 or similar hoses
to cover the jaws on the grips to prevent damage to hose

prime the fuel or run the car

clamp down on both hoses

see if the pressure holds if it does not yes the injectors or rail is leaking down

if it does release the return hose vice grip (smaller of the hoses)

if pressure goes down it the fuel regulator leaking

if not release the main hose pressure hose

then if pressure drops you have a fault fuel pump

does this help?

 

[UnderdogGN]

thanks skostur79 for your help, i will try the test tonight and figure out which one is leaking. Is there any possible way that could cause knock?

 

[UnderdogGN]

i tried the test and my fuel pump is bad It is a brand new walbro 340 i just put in. I wonder if i missed something when installing it????????????
If i do have a faulty fuel pump that would explain my knock problem.

 

[pcella84GN]

I think i have the same problem

I just replaced all my injectors along with a adjustable fuel pressure reg, next i'm going to throw in my walbro 340.... My car runs like ****, skips at idle (alot of shaking) All new plugs, wires, coil....reset my IAC. still runs like ****.

When you said "KNOCK" do you mean knock sound under the motor???
sorry dont mean to sound ignorant, kinda new at this whole GN thing.
Because after the few mods i did, along with a oil change with synthetic. i have a knock type sounds at idle, but when i rev the motor up it goes away.
didnt make this sound prior to the mods.... does anybody know what this is, along with why my motor is running like ****.

Also, I'm only getting about 9 to 10lbs of boost... What can i adjust this to
i have an adjustable wastegate.
What fuel pressure should i be running at.

Hopefully someone can help.
thank you
Paul cella
cella11@comcast.net

 

[UnderdogGN]

You may want to check and make sure you have at least 1 screen in your MAF. My dads car had no screens and it would idle terrible and miss and stumble alot. Your knock sound at idle could be your downpipe/exhaust hitting something like the frame or floorboards. Usually you can adjust it to get around 15 psi, but you need to make sure its not getting knock retard, so a scanmaster or something would be a good idea. On my car i can only get about 8 psi before it before it gets KR. I have my fuel pressure set at 40 psi with the vacuum line on and around 45 with the line off. Somewhere in that area should be good (36-42 with line on)
hope that helps

 

[pcella84GN]

thank you for responding, it actually has a new MAF sensor. As far as the exhaust hitting something i checked that as well.... Seems to be comming from the passangers side, the problem is you cant really here it from the top, but you can if your standing beside the car, or listen from underneath... could it be a rocker arm or something... Any other suggestions as far as the idle issue.. it also dosnt seem to get up and go... (it does have a new turbo)
it back fires if you give it a quick throttle. thank you for your help.

PS.. It appears to run pretty stable when i start it in the morning, the hotter it gets the more stumble and skipping it does.
Do you think it could be a fuel filter or fuel pump

thank you
paul
cella11@comcast.net

 

[UnderdogGN]

I have heard that if you buy a new MAF you have a 40% chance of getting a good one. What kind of exhaust system do you have? I bought a 3" exhaust and it bangs against the passenger floorboard under the car. That might be what yours is doing. I cant thing of anything else to add right now but i know alot of other members know alot more than me so im sure someone else will chime in and help you out.

 

[pcella84GN]

Well, when i unplug the sensor from the MAF it sounds like it's going to stall. when i plug it back in it revs up then comes down. Is that an indication the the MAF is working?

AS far as the exhuast goes, it's brand new stainless steel stock replacement.