Can anyone give me some advise on the correct flow rate for the L98
Fuel Injectors. It seem that some companies reccomend from 21-24lb/hr. My car is pretty much stock. I have one shorted and thought I may as well replace them all. Also any inputs on Bosch over Accel or etc. I appreciate any inputs. SB

 

The stock flow is 22lbs/hr. on my 90.You can run 24lbs/hr. but any higher than that will run rich without mods. I've been running Accel 24's for about 1000 miles now and am happy but some forum members say they dont hold up. I've heard that ford SVO injectors are good and If I had it to do over I may go with them just because of what I've heard about Accels in here, but so far my car is running super good on them.
http://www.madvet.com has the accels on sale for $299.00 per set of 8 which is pretty good.

 

You didn't mention the year, but you shoud be able to run the FMS 19#injectors without any issues. The 24's are going to be too much for a stock engine. The FMS injectors are rated at 39psi, if I'm not mistaken. The GM numbers are based on 43psi. So bottom line is that the FMS #/hr is underrated compared to the stock GM #/hr. rating. Check out Five 0 Motorsports for reasonably cheap injectors, and Summit Racing as well.

 

This may be true with the FMS injectors or the Ford SVO's. I know the SVO 24's are like truly 26lbs/hr. Which may be a bit rich for stock. However, the Accel 24lbs/hr. are the reccomended for 1984-93 Vettes and the 26lbs/hr. for the 1994-96. Your ECM will trim excess if needed as long as you dont go overboard, and the little extra is good to have, if you do ad some mild mods, you wont have to change to larger flow injectors. Just my opinion though, but the Accel 24's are making my slight mod 90 L98 run awesome. Proof is in da' pudding.

 

If you buy injectors different of 22 lb/h (the stock on your car) you should change your chip.
A stock car with a 22 inj. running with a 24 lb/h and a constant in the chip with the 22 lb/h value can acts like this:
in closed loop the ECM attempts always to achieve 14.7: 1 AFR.
The constant (Injector Fow rate) is at the stock value 22 lb/hr
The ecm say to the injesìctors to saty open an X amount of time knowing that the injector installed is a 22 lb/h.
So the ECM let the 24 lb/h injectors open like if it was a 22 lb/h.
So it stay open more than required. At the same time the ECM is trying to achieve the 14.7:1 AFR via O2 sensor. The ECM will detect istantainly that the car is running a bit rich ( less than 14,7:1 ) so it will command the injectors to stay open LESS. The BLM will go lower (under the 128 that is optimal ) adding continuosly corrections to the fuel delivery management. This is not good.
In the PE (over 70% of TPS on most calibrations)(Power enrichment mode) the O2 sensor is ignored and The ECM will add tons of fuel because it think It has 22 lb/h injectors. It commands to the injector to stay open more than required. In this case The best way is to lower a bit the Fuel pressure via AFPR at WOT.
The best way should be in any case to CHANGE the Injector Fow rate parameter to 24 lb/h. Doing this, ALL others parameters and Fuel tables will be right.
-Beppe-

 

I appreciate all your help folks. I found that Autopartsauthority.com
had Accel 21# Injectors for $299 for 8. I hope 21# vs 22# won't make
any difference.

SB

 

I really think you should talk to the folks at Accel first hand and see what they reccomend. Maybe you could go to http://www.mrgasket.com and get answers straight from the horses mouth. I still think 21lbs/hr. will be too lean. Mid America Corvette sells only the 24lbs./hr. for L98 and 26lbs./hr. for LT1 in Accel's and they specialize in Corvette. So I would talk to the maker and see what they suggest if I were you. My 24's and Jet performance stage2 chip and L98 work together like cold and beer.

 

What's wrong witht he Ford Motorsport ones?

 

skateparkdave - thanks. I'm very new to corvettes, so this is learning for me. I'm not familiar with the stage 2 chip. I do think that someone
upgraded the chip in mine, but not sure or even how to check.

I will do some reading and buy the 24# injectors & figure it out.
SB

 

Before you buy, you might want to check Summit. I just reveived a set of 24# Accels for my 91: $229 + shipping. (Hope they solve my problem!)

 

I put a set of the Ford SVO 24# in my 90 L98 this spring at the recommendation of a LOT of people in the forum. I got mine from Jegs.com I think for around $220. I also added the AFPR to help manage the fuel and have it set at 43# pressure (was 47# with the stock FPR). Engine is stock except for open air box and Dynaflow mufflers. Mine runs pretty good but I'm still playing with the AFPR settings a little at a time. Does anyone have any recommended FP settings using the AFPR? I had it set at 40# and just upped it to 43#. It seems like its running just a touch rich, although still pretty good.

 

On a speed density car especially, they are going to be really fat without a modified prom. It's not a biggie, virtually any chip burner could fix you up pretty cheap. A lot of guys on the Forum can make simple changes, and a few are really good and pretty reasonable.

 

'90 here as well.....very engine reacts a tad different, i'm thinking your 40psi setting was about on target, even 38-39psi with those injectors.

 

What company sells a true stock replacement producing 22lbs/hr?

 

Standard Motor Products makes a true 22 lb/hr Lucas type disc injector. They work well I have them in my car. If you shop around you can find them new for around $300. BTW they fit the rails and you can use the clips. They are not baby S**t yellow either.