Derrickclerici

I have built a 383 described below and want to know if the 30# injectors I have will be too big. I have fired it up without any sort of scan software (still figuring out which one to get) and it runs way way rich and rough. I am not sure if it is in limp mode or not since I haven't gotten software up yet. Any recommendations on software and injectors would be appreciated. I am somewhat new to TPI.
Vortec 383
mildly ported Vortec heads
ZZ4 Roller cam
9.2:1 comp
SD Vortec TPI
Stock runners and plenum
Headers with heated O2
'86 IROC TPI system (5.0)
'89 350 PROM and cold start injector disabled

I would like to get it running decent for now and dial it in later. The engine is in a '71 Chevelle that is still a long way from being on the road.

Thanks

Guest

Stock prom with 30#'ers? Yikes, yea its rich. Way rich.

rgarcia63

30lbers are what I use on my 388+. The ECM is reprogrammed, and I use an adjustable fuel pressure regulator at about 45psi static pressure.

89Warbird

I'm doing it with a custom chip and AFPR.

Derrickclerici

Would 24# injectors be a better choice? I was thinking about getting a set off of ebay.

KiLLJ0Y

iTrader: (1)

prom tuning... prom tuning... prom tuning..


hey did i mention prom tuning?

Derrickclerici

I plan to play with that eventually but I need something now to get it close enough to move the car under it's own power to the body shop and in and out of the garage etc. Right now it just coughs smokes and fouls spark plugs. I did have a scanner on it a long time ago and it was leaning itself to it's llimit (108 maybe) and it was still pouring smoke. I just don't have the time to fiddle with making my own proms

Derrick

robsgta

Then get 24 pounders

rgarcia63

In the mean time check the Coolant Temperature Sensor resistance.
For example with the engine cold, and the resistance is around 13k ohms it's correct for 20°F which is within range, and the ECM won't set a code, but it's not winter and the ambient temerpature is 70°F the resistance should be 3.4K ohms. The ECM will dump fuel to warm it up, and continue to do so because the sensor reading is offset.

hot68

Im running a 383 with Performer RPM heads and "Lt 4 hot Cam" and a First" TPI setup. Both First injections and TPIS recommended 24's over 30's so thats what I went with. FWIW mine is also in a chevelle...

robsgta

garcia63 - The ECM will dump fuel to warm it up

The ecm will lean out the mix to help it run warmer not vice versa.


24 lb injectors will have no problem supporting a naturally aspirated 383 if they do its probably the fact your pump isnt up to the push. I had a small fuel starvation problem on my GTA at one point (weak fuel pump)so I got an inline pump and the fuel pressure runs strong all of the time.

Derrickclerici

I am going to get some 24#s and check the the temp sensor. Thanks for everyone's input, this is a great site.

Derrick

rgarcia63

Hey, keep us posted on your progress.

primo

The 30#s are OK, I have 30 on my 383, you need to do some eprom burning. Runing 12.4 s ET.

robsgta

But he can run 24 pounders with no prom tuning