[solved] Big Injector fuel leak

[BSOD2600]

Pulled the injectors to have them flow tested / cleaned today (440cc, 425cc, 420cc and 420cc before cleaned). Noticed that on several of them, they had some sort of residue / carbon specs on them. Normal or something else going on with the engine? Oh yea, due to my ECU issues, it's often in safe mode which means WOT runs are in the 10 AFR range.




Edit: now the injectors are leaking big time, post-reinstall
edit 2: turns out, bottom o-rings were too big.

[ericem]

Probably normal as there could have been some oily debree in your intake that made it's way over there.

[Legacy777]

You running stock airbox?

[BSOD2600]

Stock airbox, snorkus delete with K&N.

Got a call back from the injector guy this morning. Only was able to bring them up to flow 432cc.

[BSOD2600]

Damnit, simple things are never easy.

Reinstalled the cleaned injectors. Fired it up. After all the fuel rails filled up it ran. yay.

After getting things warmed up, I noticed it was idling rough and the vaccum gauge was moving around between ~19-16 inHg, which is NOT my normal. If I let it idle a bit, it'll settle on ~18 inHg.

Think the extra ~12cc is throwing the learned fuel values off or I some how got myself an air leak? When I blip the throttle and have my head near each fuel rail, I don't hear an obvious air hissing sound...

[tahiti350]

did you reset the ECU??? When I swapped my MAF it ran like chit at idle until I reset it...

[BSOD2600]

Yes, didn't help.

Something is wrong. I have to crank it a LOT to get it to start. It then goes from barley running to running. If I unplug the injector connectors on the passenger side (1 & 3 right?), one at a time, the engine noticeably runs worse. If I unplug the injectors on the driver side (2 & 4 right), it continues to run w/o a noticeable problem -- yet the AFR does show it got leaner.

[BSOD2600]

Pulled the side cam covers off to quickly check the timing. It looks the same from earlier this month, so I think that's fine.

Next, pulled each injector back out again to re-inspect the seals, etc. Driver side ones looked fine. Pulled out the passenger ones and found that on BOTH, the 'injector seal' o-ring was cracked and/or lodged down the intake!

Cylinder 3


Cylinder 1


Since this damn o-ring isn't standard, I decided to put the injectors back in with out it and see how things go. Will try to find it tomorrow, but I'm expecting a week+ order. *sigh*.

First fire up, it takes a LOT of cranking for it to slowly catch. Then when it does, its running badly as before. With RevScan I see the 'Spark Advance' parameter is 35 deg, which is way off normal. Let the engine run a bit, notice some smoke coming from the engine bay and shut it down. Inspect the area and determine its some fuel that spilled onto things when I removed the injectors. Reset the ECU (via revscan) so all the badly learned fuel trims are cleared out, along with the timing, etc.

Fire it up a 2nd time and it starts almost normally. Notice the vacuum is ~19 inHg -- sweet, I think things might actually be ok...Slowly it starts to get worse and the vacuum creaps back to the 15 inHg range. The Spark Advance stays around 22 deg this time though. While I was paying attention to the dash and revscan, I neglected to notice the giant plume of white smoke pouring from the rear of the car. HOLY CRAP. The whole garage smelled of unburnt gas! Not sure if its just residue from the earlier flooding... but things didn't get better after a good 1-2 min of idling. Turned the engine off and am giving up for now. Hopefully the injector spacers are the fix, but thats a week or more out. I'm kind of thinking they won't be due to the vacuum leak of some sort -- or maybe thats the ECU compensating for the 2 injectors with too much fuel?

[ericem]

Man that's reallly really shitty luck, and what sucks most is there is probably a puddle of gas sitting in the exhaust now!!

The parts should take less then a week atleast at my dealership too btw!

[asc_up]

Yikes! If I recall correctly, those are the ones that fit kind of loosely around the middle of the injector, correct? If so, I found it easier to simply seat those in the rail by themselves and then install the injector because I had a problem with them catching on fuel inlet and outlet at each injector space. If I had continued to install them with them still on the injector, I'm sure they would have torn like yours did.

[BSOD2600]

Well as I suspected, the injector seal rings (costing me $32), didn't do jack. This time I installed them into the fuel rail before inserting the injector.

I also compared the injector rings which Doctor Injector gave me compared to the ones on it currently. While it's hard to see in the picture, I think the OEM ones I originally had on there are just every so slightly bigger. I put mine back on the 2 injectors.


Once again, lots and lots of cranking to get the car fired up. Once again, lots of white smoke out the back. Once the wideband finally warmed up, it was registering a solid 8 AFR (I assume its max range). I idled it for a bit... revved it for a bit... still not getting better. Finally after a few minutes I shut it off. Damn, talk about fuel dump.



Being that I've reinstalled all the injectors 2-3x now, I'm at a loss WHY the hell fuel is still leaking past. Ideas?

[BSOD2600]

I went ahead and reinstalled the stock pink injectors. After initial hard starting, it started up. Bunch of white smoke again too. After idling for a bit, it started to seem ok, except a little rough. vacuum settled on 19 inHg, which is good/normal. Engine load was around 10-15% the whole time. The wideband was showing 16-17 AFR most of the time, which is expected I assume due to the smaller injectors. After idling/revving for ~5 minutes, thing seem to be nearly back to normal again. Turned the car off, let it sit and then back on again -- it fired right up like normal.

Well there is obviously something wrong with the 440cc injectors/seals as the stock ones work just fine. I did notice that the lower injector o-ring on the 440ccs is quite loose compared to the stock injectors. But.. they've always been like that and not a problem. I really don't want to take the 440ccs to another flow shop to get confirmation that the first shop possibly messed them up.

[kimokalihi]

So your vacuum leak was the injector o-rings then?

[BSOD2600]

Well either vacuum leak caused by the ECU trying to compensate... or more likely not a good seal by the 440ccs anymore for some reason. While I havent driven around with the stock injectors yet... the car seems to behave a LOT better.

[douglas vincent]

CHANGE YOUR OIL!!!!!!!!


Your oil if filled with gas by now!!!!!

[douglas vincent]

And CHECK by rolling in fingers the O-rings on the "bad" injectors. See any cracks?

[BSOD2600]

Driving with gas in the oil is bad 'eh? Well there goes a bunch of expensive synthetic...

Will check the orings in a bit. For jollies, before reinstalling the pink injectors, I tried placing the lower oring onto the 440cc injector -- it was a LOT tighter. I assume that's how it should be and not loose where it can easily slide off, right? Wonder if that's my problem all along.

Planning on getting a fuel pressure tester, hooking it up and then watching the gauge change as I install a single 440cc injector at a time. Should help to tell me if its the orings or injectors themselves which are the problem, right?

[BSOD2600]

Yesterday, hooked up the fuel pressure gauge right after the fuel filter. With all stock injectors in, right after the ignition is on, the system is pressurized to 32 psi and then slowly tapers off. Put in 1 440cc injector, pressurize the system and right away the gauge drops down. Then, I took the bottom o-ring off the stock injector, put it on the 440cc and retested things -- it held pressure just fine. So it IS the damn o-rings.

Drove back to Doctor Injector and explained the problem. He was puzzled. We went back to his workshop and I saw him flip through his injector book, double checking the correct o-rings were used (book showed the injector for nissan/subaru) -- yet they were clearly too large. Next, he went through his o-rings drawers to find one that closely matched the stock o-ring and gave me a set of them. He also gave me this golden lube stuff (forget the name), which was to be put onto the o-rings during reinstall since its really slippery.

Once back home, installed each 440cc injector one at a time, pressure testing the system after each one. First fire up of the engine took a lot of cranking, I assume due to all the fuel that dumped into the engine after each injector change. After idling a bit, vacuum was around 19 inHg and the exhaust smelled normal. Short term fuel trim was at least in the positive range this time too -- once the O2 sensor warmed up. Oh yea, with all the times I've had to take the injectors in and out, I'm soooo glad I replaced those damn screws (which heads easily strip off) with 8mm bolts. Much better solution.

Today, will try to get the pictures of things posted. Also have to install the stage 2 chip update I got. Then can finally drive the car around and see how it behaves.

[Legacy777]

Good deal. Glad you got it squared away. Damn o-rings.

[asc_up]

Good to hear!

[BSOD2600]

Well, I might have myself a bigger problem now...

Let the car idle till the temp needle shows some movement. Went for a short 3 mi drive around the block. On the return loop home, I noticed there is a noticeable amount blueish smoke in the rear view mirror. I'm hoping it's just because all the gas dumped down the cylinders cleaned some crap off, which is now starting to burn off.

I'll drove to/from work today (40+ mi of highway) and see how things go. Sure hope it clears up.

[asc_up]

Update?

[Adam West]

Chris, Wow, I must have gotten lucky with my 440 injectors - got them flow tested and new orings at Dr. Injector too. But haven't yet had a problem. Are you working with Art down in Renton? He was a really straight up guy...did he charge for the new gaskets? But I guess it's a local franchise and some other locations might not be as good... Cheers,

[BSOD2600]

Here is the size difference of the o-rings. The larger one is obviously the one which couldn't create a seal.



Guess it was just residual crap that the gas cleaned out. Doesn't appear there is any smoke in the rear view mirror while driving. Yay.

Adam: I went to doc injector in Kirkland... think the guys name is Tom. Renton is too far of a drive for me -- north Seattle .

Well its been a good 150 mi since the injector reinstall and ECU reset. Idle is nice and stable now since it can trim out the fuel more (instead of limited to 14.7%). Notice the other fuel learned parameters are not linear either -- kinda funky. Anyways, reset fuel trim cells 4-7 to 5.5% and will drive around more to see how the ECU changes things.

Now I can resume my ongoing ecu learning / knock issues.... *sigh*.

[race_to_live]

ok after reading this i have the exact same problem. the car idles like crap. its throwing all injector codes. when i pull the injector clips on the driver side the car really wants to die. but when i pull them on the passenger side nothing happens. so was the o rings a fix for sure? if so where can i get them and is there a part #?