Back fire at start

[1990 quasar blue]

Unless they have changed the accells are 21 lbs. I believe factory are 22.8 lbs. Something you should tell Marc when you order the chip, if accells are what you decide on. Another thought regarding Marc and your chip. Does NH only have 10% ethanol like we do here in ma?

[GOLDCYLON]

Originally Posted by efnfast

Thanks GC, you missed my point. Not GM injectors, but the actual size and rating of the injector. Like diferent size jets in a carb. Can I put in an injector that will flow more fuel and give me a bazillion more hp?

Only if you add a Turbo type R sticker to your rear window.


The real answer is no unless you have had porting and headwork you need more fuel delivery in those situations because the flow has improved and changed. Simply adding larger fuel injectors wont do the trick.

[efnfast]

GC, already put the type R sticker in the rear window, didn't add nearly the hp they advertised. Nothing ever does.
1990 QB 10% ethanol for now.
So it sound like, unless my hand is forced, I'll wait until the car goes to Marc for porting to do the injectors, then Marc can pick them, seems he kinda knows what he's doing.

[GOLDCYLON]

Originally Posted by efnfast

So it sound like, unless my hand is forced, I'll wait until the car goes to Marc for porting to do the injectors, then Marc can pick them, seems he kinda knows what he's doing.

Concur

[scottfab]

Originally Posted by efnfast

Thanks GC, you missed my point. Not GM injectors, but the actual size and rating of the injector. Like diferent size jets in a carb. Can I put in an injector that will flow more fuel and give me a bazillion more hp?

This has already been answered but I'll add that if you ask the RC folks they will confirm unless you're upward of 500hp already then the flow will not benefit from higher flow injectors. I replaced all 16 of them 12 yrs ago and have had no problems with them since.
=D>

[XfireZ51]

Originally Posted by 1990 quasar blue

Unless they have changed the accells are 21 lbs. I believe factory are 22.8 lbs. Something you should tell Marc when you order the chip, if accells are what you decide on. Another thought regarding Marc and your chip. Does NH only have 10% ethanol like we do here in ma?

The difference in fuel flow is actually non-existent. The Accels are rated at 20#/hr w 39psi FP. At the more typical 48-50psi in our Z's they flow ~23#/hour. So no calibration change is necessary.

[Paul Workman]

Originally Posted by efnfast

Thanks GC, you missed my point. Not GM injectors, but the actual size and rating of the injector. Like diferent size jets in a carb. Can I put in an injector that will flow more fuel and give me a bazillion more hp?

Negative. The proper AF ratio is what will give you the best performance; somewhere around 12.8 to 13.0:1 reading on a wideband sensor while tuning. Bigger injectors in closed loop will require less dwell time to satisfy the pre-determined AF ratio. As injectors get bigger, the dwell time gets shorter (in closed loop, i.e., idle) until the dwell time gets so short that the injector doesn't function well anymore and idle quality goes to hell.

Dom's right. On the WOT side, the stock 22# (or the 21# Accels) are more than adequit. Best power is made when the AFR is usually around 12.6 to 13.0 (varies with motor and atmospheric conditions at the time of testing), and there's plenty of dwell time left, even on a 500+ hp LT5. (Besides...IF it were that easy, we ALL would have spent a couple hours to swap injectors to some mega flowing injectors by now, instead of doing all that porting etc, etc. Just a thought.)

Just another thought... Take it from one who had a single injector go bad, you can end up burning a valve on that cylinder, especially if you're running with the secondaries intact. (another reason to chunk the secondaries, IMO). So, at least do a (hot motor) injector resistance test - all should be about 12-12.5 ohms for stock injectors. At 10 ohms, you have trouble on the way, and at 7 ohms...your idle may be the least of your worries!! Do whatcha want. I'm just sayin the 90-92 stock injectors can result in more than "minor" issues with idle/performance.

P.

[efnfast]

Marc is going to have a chip for me at BG. He's going to calibrate for 12.8:1 AFR.
I asked about a custom tune, he said not at BG, too busy.
I'm going to send a letter to the p.o. and see if he'll share any info. He may have already done injectors.
So if I change injectors now, I'm still covered when I get to the 500 hp range?

[RHanselman]

Originally Posted by efnfast

Marc is going to have a chip for me at BG. He's going to calibrate for 12.8:1 AFR.
I asked about a custom tune, he said not at BG, too busy.
I'm going to send a letter to the p.o. and see if he'll share any info. He may have already done injectors.
So if I change injectors now, I'm still covered when I get to the 500 hp range?

He tuned mine in 3 pulls @ BG several years ago and did a great job! I even got 4 more MPG on the way back to Vegas. 28 vs 24...