ncsi

So I have a turbo gsr. Stock fuel rail with Aem fpr and precision 1000cc injectors. From the car im parting out I took the an line from fuel filter to Aem fuel rail, the fuel pressure regulator and the precision 1000cc. Installed on my car because I was thinking I had a leaky injector.

Well got everything installed noted the fuel pressure he ran was 60 so turned it down to 42 which is what MY car has always been at. Well the car idles like ****. Wideband reads really lean. Really the only differences are the Aem rail and an line. I switched to the same fpr and injectors that were known to be good...the car sounded like it was running on 3 cylinders but all plugs and injector clips we're on tight. Any ideas?

non-VTEC

if the car was tuned and running on 1000cc injectors @60psi then you should leave the pressure at that. lowering the pressure will throw off the tune on such a large injector and will cause it to run like ***.

nealnanoHX

Big plus one. Set it back to the fuel pressure it was tuned on are try again. You are giving the motor less fuel now with the lower fuel pressure. You either need to put it back to 60psi or increase injector duty cycle in the tune.

ncsi

The car I got it off was at 60 mine has always been 42 at idle that's why I turned it down...

darkhorizon

ncsi

Please keep bs out of my thread. Im on my droid sorry for initial post being confusing!

nealnanoHX

Are you sure the injectors you changed out are the same size as the ones you tuned with? Did you have theses injectors tested and cleaned before you used them? Never trust used injectors always send them out for testing and cleaning before using. I mean its only the life of your motor that depends on it.

ncsi

I know they are good. Only have 200 miles on them. All the parts came off my buddys car I helped build that's turbo took a **** after 200 miles. The rail and fpr only have 200 in them as well. Both sets of injectors are precision 1000s!

h22apwrd95

iTrader: (1)

Are you using the same FPR or a different FPR? Could be an issue there as well. Where is the gauge mounted as compared to previous? I would definitely look to the injectors being a possible issue. What fuel was it run on and how long have they been sitting?

ncsi

Both are Aem fpr I just wanted his cause it matched his fuel rail. Gauge is mounted on fuel filter like it always has been. The injectors sat for maybe 2-3 months and we have both been tuned on 93...

h22apwrd95

iTrader: (1)

Change the FPR out for your original FPR. I personally would still have the injectors cleaned. Mine were in my car all winter, sitting in the garage with E85 in the rail the whole time. I sent them in for a clean and flow check. Will make sure to pull them and dry them out next winter.

ncsi

Well I think im gonna throw ny injectors back in and if that doesn't work ill put my rail and fpr back too!

nealnanoHX

If using the AEM fuel rail the pressure gauge should be on the fuel rail not on the filter, this gives you the most accurate fuel pressure. Even sitting for a few months can cause the gas in the injectors to go bad, have them sent out and cleaned.

ncsi

I have a b&m gauge so it will not be going on rail

Whiterice-gsr

why wouldnt u try it at 60 psi before changing everyhting again.

ncsi

Because mines set up at 42...

ncsi

It did the same at 60. Wideband was very lean

Whiterice-gsr

gotcha, strange.

m3tech95

Umm are you sure the injectors you swapped out are of the same resistance? If the precisions are low and the ones you removed were high it would explain the crappy idle...if that doesnt work then get the injectors flow tested....WHY? Because injectors flow at different rates especially USED injectors. You may have a situation were the injectors you tuned with were all flowing at different rates (2-6%) of each other, and now you have newer injectors flowing closer to say (within 1-3%) of each other... do a little research on injectors and I guaruntee you will send them out to get flow tested and be glad you did. Its a very overlooked issue and a reason many setups blow up...$20-50 is not worth cheaping out on to risk having inaccurate fuel flow to resist detonation. Just a thought.

ncsi

Im just gonna throw my injectors back in when I get a chance they worked fine. Thats what I figured since injectors are matched as a set when sold. Both are peak and hold precision 10000s!

the_penetrator

so its running lean hmmmm fuel spark or air try advancing or retarding the time at 42 like u had it tunes but make sure u mark it with white out or marker so if it doesnt work u know exactly where it was for when u put the old ones back on,, u also put on there u thought u had a leaky injector before changing them y would u say u had a leaky injector? was it missfiring? or it smelled like gas? 1 check for spark 2 the injectors should be good like you said, and 3 the intake is the same so that shouldnt be a dealing with after that take your sparkplug out look for rust or milk lol u know what that means HG or look for the one that doesnt smell like gas u could have a failed spark plug as well so check those plugs since u were running turbo. and if its lean and u have a wideband keep adding pressure until its reads right then work from there if it isnt doing a differene when adding pressure then im sure its gotta your spark plugs. but a leaking head gasket will cause it to missfire too like drops of water on a candle,, look for steam in your exhaust im sure you know all this stuff...i know you want to save money and not spend so thats your best bet if not i would just put the old injectors back on lol hope the issue doesnt continue after the old injectors are on. and also in consideration of the comments above on the duty cycle and difference in injectors for used and new and percentage on each set

ncsi

Before I just has a small misfire /hiccup around 3500 rpm partial throttle. All spark plugs looked good except one making me think It was injector related since my dizzy was rebuilt and we tried another one. Leak down and compression results were perfect. 200 across board compression. Maybe just something in spray pattern or possibly tune but I trust my tuner...oh well ill get to it this weekend. Gonna throw my spal fan ob as well

mechanix619

This is a long shot but did you replace or at the very least make sure all the o-rings were in good condition and seated properly? You might have a fuel leak, though I'd expect you'd have smelt fuel.

the_penetrator

hmm missfire around 3500 rpm check all your hoses vaccum all of them follow all of them as well even the ones that you know are good look for a leak or also look at the hoses and make sure they are all the size they are soppose to be if its not getting enough air somewhere that will cause it to do that check the gromets like mechanix said if u have that one spark pllug that u said looked different from the other ones then you know exactly wich cylinder it is so check that spark check the gap on the plug check that fuel injector turn it on with out the spark plug make sure theres fuel being put in it whats good is that u know wich cylinder it is so its 1 of those 3 issues spark fuel or air

boosted_D

iTrader: (1)

This a very simple thing to isolate and fix......swap each component back to the way you had it before one at a time, as soon as it runs good again you have found your faulty part....Start with injectors, then fpr, I doubt its the rail, but I suppose it could be if it's clogged.