Put a set of Accel 23# injectors in my 88 with the L98, very lightly modified, K&N filters, air foil, cat back exhaust, 3:23 rear axle. Factory set fuel pressure. Car runs OK, no problems and it is much smoother than before with the shot RP multec stock injectors. Three tanks of gas so far and ave. mpg is 23.4, probably one mpg at least better than before.
Scanned the ECM at 60 mph:

Int. 128
Blk. Learn 114
O2 CC 164
Inj Pulse 1.9

Looks like the 23# are about right for this engine.

 

It looks like you are rich in that particular cell. You need BLMs around 128. Your INT should be trying to pull your BLM up.

 

I am wondering if 21's would be better for a bone stock 350. 114 is rich

 

Any inj rated more than 22psi will force the block learns rich :-)

period

swapped svo 24# onto my GTA which is stock and had to adjust the onj condtant to 24.5 in the chip to compensate.......

forced blm's to low regions , past 108 it no longer compensates when stock, mine hit that occasionally and ran around 11o-114 otherwise...

Its on the edge, way to close foir my liking so I fixed it.

check the prom board for more info on how to get started
later
Jeremy

 

Interesting. Did note the first tank of gas gave around 21 mpg, the second over 23, and the third was 25 something. Maybe it's time for a set of headers? I'll run it some more and keep an eye on the numbers. Should have scanned it before I suppose.

 

Would 21lbs be good with an AFPR for a stock 350 (except ehaders)?

 

In regards to Toms numbers he posted, its tough to tell anything when only 1 small piece was posted. You need to have a complete datalog while driving and at idle so you can see what the tune is. You might be lean in some cells(doubtful but you never know) and on other cells you could be closer to 128 on BLM's. Mind you you could be pegged at 108 as well. Its impossible to guess. If you can post a CSV file of a datalog I am sure someone here can let you know whats going on!

 

Last time I checked, 21 pounders were STOCK on an L98.

 

Last time I checked it was 22lbs/hr at 43.5 psi. This refers to the RP multecs found in most l98's.

 

19lbs. = 305, 21lbs. = 350


thats the way it's been as long as I've known my tpi.

 

It looks like your tpi is an LB9 so you are forgiven. Its 22lb/hr for an L98 .

Scroll down to almost the bottom for factory GM specs:

http://members.shaw.ca/s15/Fuel%20Injector%20List.htm

And yes the 1990-92 L98's had 22lb/hr injectors as well. Do a search on TGO and hundreds of references will come up.

 

22's 21lbs is 40.5 PSI I believe

 

Yeah you can drop them down to 36ish without too much fueling problems to achieve a desired flowrate. I know on the 22lbers I sold you don't like it much over 50psi. they seem to want to lock while under load. I have heard a few guys mention that with the RP Multecs. I have injectors from an LS1 now. They can hold 60plus psi all day long. I just wish I had the need for that much fuel. I run mine at 44 with a constant of 25lb/hr. That seemed to be the best starting point for BLM's when I started tuning with my prominator.

 

I have the slp 25's nd witha 25 constant I was at 108 alllllllllll day. needed to put it at 28.5 to get it nthe 120's

 

I believe they were the same injector. What psi do you run yours at?????

 

Stock pressure , whatever that is With the constant et to 28.5 my blms a idle are 122 and driving around down 126-127 Highway is about 129-129 Whn I let off the gas it goes to 118

 

I just got a 91 Z with an L98. the car has full SLP exhaust with 1 3/4 headders and ported and siameased intake. the guy I bought it from aslo said he put in 26lb injectors and gave me a fuel preure regulator with it. He said the Presure was in the low 40s but could be bumped up to like 46 lbs when I took it to the track or something. Does this sound right?