I just finished my 383 install, and it runs so rich at idle that it smokes out the exhaust, spark plugs are black, and gas can be smelt on the dip stick. It is a HSR equipped engine with 10.5:1 comp, ported edelbrock performer heads and a comp valve train. Here are the specs on the cam dur @ 0.050 230/236 lift .510/.520 LSA 112. With SVO 24lbs/h injectors edelbrock headers and exhaust. T56 transmission.

Ok heres what I have tried so far: Checked for vacum leaks/ air leaking past the MAF OK. Double checked timing 6deg advanced.
Cheked and adjsuted fuel pressure to 43 psi. Did a hot valve adjustment. Checked PCV OK. Checked coolant temp sensor and IAT sensor both OK. MAF was recently replaced checked with DVM seems ok. I am currently wiating for my scan tool I might see it tomorow but probably monday. Checked the O2 sensor with DVM at ecm connection and it shows from 450-650 mV at idle. Pulled the sensor out and did the propane test and it goes up to the 900mV's or so and then back down to 0mVor so. Tried feild service mode rich/lean test and ses light flashes less than once a second so I think that means the computer is trying to enrich the mixture. Put stock 88' 5.7L98 auto chip in and same problem is there I thought for sure that would make it lean.

I am out of Ideas, at least untill I get my scan tool and can look at the BLMs and MAF g/sec. But I might try replacing the O2 but I have my doubts something is causing the ecm to pour the fuel to this thing but I dont know what?? Anyone got any Ideas???? Vader????

 

You need a scan tool. It will tell you what you need to change. I'm using TunerPro hooked up through the ALDL. Works great! Check out the DIY cables or AKM, get a laptop, dowload the software from Mark Mansur ($30.00 donation) and your all set.

 

You don't know what the ecm is seeing without a scan tool.

 

Okay I got my scan tool and heres some values.

BLMs are 108

MAF 9.9 g/s avg.

Pulse Width 1.98 avg.

O2 0.59 V avg.

what do you guys think??????

 

Have you tried visiting www.stealthram.com? I bet someone there could help you with this issue.

 

ttt

 

big cams will idle 'dirty'. meaning idle will be rich. mine did that also. i changed the MAF table 1 until i got the idle and readings somewhat reasonable. into the 118-120s i think. i no longer have my 383 HSR. but, i still have my tunercat program, moates adapter and flash chips, and pocket programmer. i dyno tuned it before i sold it. if you want you can buy all my stuff and start from where i left off. click the blue banner to see what i had in my 383.

 

Little knowledge on this as I'm still learning. BLM lower than 128 is rich, 128 is the goal (14.7 AFR or close), higher than 128 is lean. Just a starting point for you. You'll need to work on your VE tables after you have changed all the essentials (new ci, injector size etc..). I just started using the Prominator and it is working great. It was easy to install and easy to use with Tunerpro. Good luck!