I've a brother with an 89 RS who wants to use the stock injectors from my 87 IROC. I am doubting this, but is their a possibility for these to work? (without an adjustable FPR, and chip mods)

 

Is this just one of those stupid questions that I should know the answer too but dont ? (that happens on occassion)

 

2.8l 6 cyl is .47 liter/cyl.

5.7l 8 cyl is .71 liter/cyl.

I have no idea if they physically will fit, but just from a "size matters" standpoint, it would appear they would be way too big.

But, perhaps the V6 guys could shed some light.

 

They should physically fit, but they will flow way too much fuel for the 2.8L engine. It will end up running really rich.

The injectors on the 2.8L engines flow 15pph (or was it 13?)
The injectors on the 5.7L engines flow 24pph (or it may have been 22, I'm tired today).

That's a big difference. You'll need injectors that flow the correct amount for the engine's requirements. Besides, the ECM is also calibrated to run using those 15pph injectors.

 

2.8 = 13pph
5.7 = 24pph


IIRC, anyway... they will fit (i'm using some) but they flow too much, with no other changes.

 

Print out I got from Cruzin' Performance when I got mine cleaned says they flow 15pph. Or is that just for the bench test and 13pph is in operation in the engine?

 

Correction.

L98 5.7 TPI Injectors are 22-lb/hr.
LB9 5.0 TPI Injectors are 19-lb/hr.

Yes they will fit but you will basically puddle the engine. In return you;ll just wash the bearings. That is if it will run right at all.

 

I have some 19's that I will be trying on mine soon with the new Holley AFPR I just got.

 

Ah.. I see.. then it would not be prudent to attempt this then. Thank you.

 

Unless you do some tuning (computer, not the regulator), its going to be way rich. Redraif's car has a 3.4 with 19lb injectors, with the Holley regulator, cam, ported heads, etc, and they are way too big as is. With tuning, they may be ok...when we put them in we didn't realize the stock injectors were so small ( I had guessed 17lb or so). Hopefully that issue will be corrected soon on her car...as will the restrictive stock intake problem!

 

LT1, Thanks for the headup, but I was already planning on computer work to possibly get them in there. I am going to have a baseline reading done on the computer before I install the AFPR and then try and boost the pressure of the stock 15lbers up as much as I can to see whats happening down low at idle with the prom I am currently running. I really think I am running out of fuel with the rpms I am turning. The new TB is producing a new power gain about 4200 rpms but I don't think I am seeing its potential up around 5-5500k.

I am worried about running the 19's too low of pressure also and not getting a good atomization of fuel due to weak or low fuel pressure going to the injectors in order to run the larger without flooding even with chipwork- I have some local experts that I will be hiring to help with the tunning(Kevin91z & DynoDon: Don & Kevin Lorentzen). I have alot of experimenting and additions to tinker with in the near future and want to get readings off of each progression.

Basically the readings I will get off of the 15's will tell me if I can bump up to 19's or if I'll have to stay one up with 17's. My concern is mainly idling fine AND running 3500-5500(5800?) range with the modification I have and am adding in this learning process.

I know this is a little 2.8 but I am currently running a 16sec flat 1/4 as it stands now. The drivetrain allows and craves high rpms and the header addition (mainly y-pipe) is going to help that dramatically. This car is putting out some decent power right now for a 2.8. when I pop the 3.4 in it with the Supersix heads (big valve versions), & .470" lift I will definately need the 19's at that point