BadSS

MAF hot rodders , did you have to have a custom chip when moving from 19# to 24# injectors? I’m running rich at idle. If I had the original 19# injectors,, I’d try them,,, but someone has to know this question all ready. The stock 305 chip does fine for me part throttle and WOT,,, so I’m not really worried about a “performance” fuel map or ignition curve,,, I just want the thing to idle “clean”. Custom chip??? Or,,, are there some magical tricks to lean idle out,,, and not the rest of your fuel curve????

------------------
86 IROC - 9.8:1 - 355, TFS twisted wedge heads, 218/228-110, fully ported GM base and plenum, SLP runners, 52mm BBK, 24# SVO, 1 5/8" Headman headers, 3" Dyno-max, TH350, B&M Megashifter, 245/45ZR17s on 212 Eagles

Kevin91Z

iTrader: (1)

You're gonna need a custom chip with a severely lean fuel map to keep those 24# injectors from flooding your engine all the time. 24# SVO injectors are rated at 39 PSI, so if you put them in a 45 PSI Chevy TPI, they flow about 26-27#, too much for a stock setup.

------------------
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

Corry

For a 350 l98 what would be the magic numbers? I may have to replace my injectors...I have a lean condidtion being reported from my 02 sensor periodicaly...I am afraid the sniffer isn't going to like that. I also think my injectors are leaking. I am going to check my fuel filter...possibly tunneling through it?, and maybe try an AFPR to drop the pressure, but if those injectors are leaking, I don't think anything will help short of replacing the injectors. Therefore, I will as always when I replace a part, go to a performance part, like 24# injectors
Thanks
Corry

BadSS

Kevin91Z thanks for the reply, but this set up is far from stock (check the sig),, and it's not flooding, just a little rough at 650 -700, very drivable,, just running rich at idle,, like a badly tuned carb. Granulates the tire (needs a posi unit)from a 30mph roll, but right now,,, I'd trade some of that for a clean idle.

------------------
86 IROC - 9.8:1 - 355, TFS twisted wedge heads, 218/228-110, fully ported GM base and plenum, SLP runners, 52mm BBK, 24# SVO, 1 5/8" Headman headers, 3" Dyno-max, TH350, B&M Megashifter, 245/45ZR17s on 212 Eagles

Roy

With the tight centerline, long duration, stock chip and 24 lb injectors I am surprised the car idles at all. My opinion is that you definitely need a custom chip. I think you will see improvements everywhere.

Jim85IROC

iTrader: (2)

I'm running 24lb/hr SVOs with bumped fuel pressure on my 350 with the stock 305 chip. It runs a little rich, but overall runs pretty well.

------------------
The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
"I didn't know a bored out Ford could go so slow" -Shenandoah

BadSS

Roy,,, LOL it didn't at first. I came close to carbing it - I can tune those - but after feeling how much low and mid range torque this TPI has - and still pulls to 5500 rpm,,, it's not an option anymore.

Jim,,, thanks, now I don't feel like the lone ranger. It's pretty smooth at idle, just a little too rich for me (like a bad idle adjustment on a carb). I installed a heated O2 sensor,, can't really see where it helped much,, if any,, but I figured it was worth the shot. Actually there was another guy that said he was running rich at idle,,, with a similar set up and "hated to stop for traffic lights". That's been me when I've driven it,,, I can't stand to get behind someone running as rich as I am.

Actually I'm getting a chip burned and hope to have it soon. I'll let you all know how it turns out.

Thanks again for everyone's replies!!!!!



------------------
86 IROC - 9.8:1 - 355, TFS twisted wedge heads, 218/228-110, fully ported GM base and plenum, SLP runners, 52mm BBK, 24# SVO, 1 5/8" Headman headers, 3" Dyno-max, TH350, B&M Megashifter, 245/45ZR17s on 212 Eagles