ElkySS

iTrader: (6)

iv been running around on a base tune for a while now and am getting ready to go get my car retuned. i have the new style SVO red top injectors. there was something someone told me about them to make sure i told my tuner but i forgot what it was. something about the operation pressure i think?

ss.slp.ls1

iTrader: (36)

IIRC the SVO injectors are rated on a 3 bar system while LS1's (and as far as I know LT1's as well) run on a 4 bar system. But any knowledgeable tuner should have experience with SVO injectors on a LT1/LS1, if not, I would be worried.

EDIT: Now that I think about it, the LS1 usually run at a high fuel pressure than LT1's so the LT1's might in fact also run on a 3 bar system like SVO injectors were intended to. But I would do some research to be sure.

ElkySS

iTrader: (6)

do you think if just a base tune for 30# injectors was applied it would cause a missfire only at WOT in the higher rpm ranges? my tuner isnt very close to me and im trying to make sure im not gonna have any problems once i get there

ss.slp.ls1

iTrader: (36)

Could be anything really, coil, plugs, wires, opti, fuel pressure, etc. You could try to get it data logged, but if you are only running on a base tune, I wouldn't know exactly what to expect to see.

ElkySS

iTrader: (6)

well i tested the fuel pressure at wot and it stayed at 40 psi then slowly dropped to 30 psi at 6300-6500. this was with the hose off the regulator. i replaced the pump and it fixed it for like a day. then i put on a hotwire kit, fixed it for another day, new pump regulator, injectors, filter. the pump is an airtex tho. i might just call up warrenty and pay a couple more bucks for the delphi.

ss.slp.ls1

iTrader: (36)

The fuel shouldn't be dropping off at all (as far as I know). I remember when I had a high rpm stumble, I thought it was an ignition problem...turns out my fuel pressure was dropping to 20psi at around 5800 rpms. Swapped in a Racetronics kit w/ a Walbro 255lph pump and the stumble went away.

I don't know if 30psi is enough of a drop to cause a stumble or not.
I would check out everything to be sure.

ElkySS

iTrader: (6)

well the car does have a really crappy tune on it right now. im just trying to figure out if a tune can fix this. i have the racetronix kit. everything but the pump. my pump is making a little noise tho. i might warranty it just for the hell of it

blackz93

iTrader: (2)

Those injectors are rated at 39 psi and LT1s are 43.5... if that's what you were wondering.

DAVE00

iTrader: (10)

Correct and on our cars, the SVO 30's are actually rated at 32-33# flow due to the higher PSI in the LT1 fuel system.

Puck

iTrader: (17)

SVOs are rated at 43.5 just like lt1s. Back in like 02 we all thought they were rated at 39, but after multiple people flow benched them they found them to flow the rated #s at right around 43psi.

Also, they noticed that even though they perform better at low pulsewidth, high rpm use, the injector to injector variation was slightly higher then standard rochester type LT1 injectors.

ElkySS

iTrader: (6)

ok well i just got a message from my tuner. he said this problem isnt caused by a tune. so what else could this be? im getting ready to just buy a racetronix pump. but i dont wanna spend the money right now.

blackz93

iTrader: (2)

I'm sure the new design injectors are better, now.

ElkySS

iTrader: (6)

ok well i just said **** it and bought a racetronix pump. it will probably be hare l8 next week. ill install it and let you guys know if it fixes it. if it doesnt im fresh out of ideas