fuel injectors stuck open

Post by **srpowered240sx** » Mon Oct 10, 2005 8:17 am

i have now dropped 3 fuel injectors due to them getting stuck open. runs on 3 cylinders, tons of white smoke, then it will start spraying fuel 6 feet behind the car. am i the only one this has happened to, i have searched, but to no avail, no one seems to say it has been a problem for them. it has been 3 seperate cylinders about 4 months apart, so, i dont know what could be causing it, and the new inj. fixes the problem. is it a common sr20det thing??

Post by **Nismo_Freak** » Mon Oct 10, 2005 10:10 am

Odd, it's not normal for 3 to fail.

Post by **ca18det_boy** » Mon Oct 10, 2005 6:32 pm

what psi are you running? is it the factory turbo?

Post by **TogueDrifter** » Mon Oct 10, 2005 10:22 pm

white smoke would meen that he's burning water/coolant... blown head gasket or some gasket?

Post by **srpowered240sx** » Tue Oct 11, 2005 5:39 am

im running the factory t25 turbo on stock boost, except on the occasion when i wanna push the button to 11psi, but not often. compression checked clean across the board a month ago before all this injector shenanigans started again. ive been doing this long enough to know the difference between the aroma of burning coolant, and a spray of fuel coming out my exhaust. it was raw fuel getting blasted out the exhaust, the white smoke was some of it burning and vaporizing with the heat. the injector fixed the problem, i am just trying to figure out if i have a deeper underlying problem that makes the injectors get stuck open. i put on a new filter for the hell of it, but it was super clean so i dont think my tank is dirty. im just confused on why i continue to kill my injectors.

Post by **ca18det_boy** » Tue Oct 11, 2005 5:48 am

only thing I can think of is check the voltage going to the injectors and make sure they're getting the right signal. At 11psi your not even close to maxing out the duty cycle on them so I don't know why they would be stuck open. Try checking that and get back with us.

Post by **srpowered240sx** » Tue Oct 11, 2005 6:34 am

i'll do that today, is there a certain voltage i should be looking for, or just uniform numbers accross the board??

Post by **TogueDrifter** » Tue Oct 11, 2005 6:28 pm

sounds like it

Post by **Hijacker** » Wed Oct 12, 2005 5:27 am

one question i'm surprised hasn't been asked yet is what PSI your fuel lines are running at. This could be a problem of an FPR getting stuck.

Just trying to eliminate one more variable

Post by **srpowered240sx** » Wed Oct 12, 2005 5:50 am

tenkawa_akito wrote:one question i'm surprised hasn't been asked yet is what PSI your fuel lines are running at. This could be a problem of an FPR getting stuck.

Just trying to eliminate one more variable

word, i like your thinking, i was actually gonna get a nismo adj-fpr, but havent gotten around to it. i do however have an inline gauge, and i am running 38-40psi, then bump the throttle and it goes to 45psi. i thought this was kinda high, but it runs good, so i dont know. another oddity is my fuel pressure is perfectly solid, then i shut the car off and it drops, within 30seconds it is at about 5psi, then holds for a half an hour or so, then goes to 0psi. my roomates turbo crx will hold fuel pressure for a few hours, which is more normal??

Post by **ca18det_boy** » Wed Oct 12, 2005 6:08 am

HAHA and here comes Bart to the rescue....I don't know why I didn't think of that...I guess I always want to do things the hard way.... Good thinkin!

Post by **PROJECTRB240SX** » Wed Oct 12, 2005 9:31 am

STOCK WITH OUT REFERENCE IS 43.5PSI (OR 44 FOR EASE). WITH THE VACUUM REFERENCE I GET AS LOW AS 35PSI AT IDLE (PULLING 20 INCHES OF VACUUM).... SO TO ME IDLING AT 38-40PSI IS KIND OF HIGH BUT NOT HIGH ENOUGH TO BLOW AN INJECTOR.

ON THING TO THINK ABOUT IS YOU MAF.... MY WAS WATER DAMAGED AND THE COMPUTER MAXED MY INJECTORS TO COMPENSATE EFFECTIVELY DAMAGING THEM (LEAKS CONSISTANTLY AND ITS NOT THE O-RINGS), YOU MIGHT WANT TO SEE IF SOMETHING SIMILAR HAS HAPPENED.

Post by **Hijacker** » Wed Oct 12, 2005 9:42 am

fuel pressure is fine.

Get a noid light. It's a test light that you can put in the injector plug. It will pulsate as the car fires that injector. Test all of your plugs to make sure they're working properly. It should just flicker, never actually staying on and getting bright.

What I'm trying to get you to check is to see if any grounds have been futzed up. Sometimes, a ground wire may be grounding out the injectors and they stay stuck open.

One other option is to try a different ECU. could be that yours is on its way out and is doing some funky things with the injectors.

These are, of course, just a couple of possibilities.

Post by **srpowered240sx** » Wed Oct 12, 2005 10:37 am

thank you guys for the great help. i am gonna find a noid light as soon as i get back to work. the maf is a good idea to check, i am running a sohc maf now, but just got my new sr20det maf, so i will swap those after work and let you know. yeah, my pressure sounds normal, i too am leaning towards something electrical. my grounds all seem good, i have a grounding kit, maybe i will relocate the ground on the intake mani and see if that is effecting it. small town syndrome limits my ecu swapping, but i know one guy that has an sr, so ill talk to him about switching them up. thanks again and keep the suggestions coming, i will keep you guys posted.

Post by **Hijacker** » Wed Oct 12, 2005 6:19 pm

the injectors are supplied with constant power, and the ECU grounds them for the pulse duration. So if say one of the grounds from the ECU gets a hole rubbed in the sheathing, that injector will get grounded out and stay open constantly.

Of course all of this is based on having no knowledge of what's been done to your car. ALl I know so far is that you've had the motor swapped, a fuel pressure gauge, and a grounding kit installed.

I've seen where someone had installed a stereo unit, had done some drilling in the firewall, nicked the wiring harness, and started burning up injectors and fuel.

Similar incident on a GM that a friend of mine worked on, except the harness had been rubbed from wear and tear and wore holes in the sheathing. He could literally make the car run perfect, or run horribly by moving the harness around.

Post by **srpowered240sx** » Thu Oct 13, 2005 5:04 am

wow, then i have some wiring to check. the harness connecting all the injectors looks good, no rub marks or cracks in the loom. ill have pull the ecu to check the wires on that and the ground. good suggestion. i also changed my maf to my sr20det for giggles since i had one. so far so good. there have been a lot of things installed, but the problem never presented itself as a consequent of a new part.

fuel injectors stuck open

fuel injectors stuck open

Re: (TogueDrifter)

Re: (ca18det_boy)

Re: (tenkawa_akito)

Re: (tenkawa_akito)

Re: (tenkawa_akito)

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