Mods are in the sig. I have had previous post in regards to my high idol problem. Just finished rebuilding my stroker, I go to start it and the rpms take off to about 3 grand. I have checked everything. ALL vacum hoses intake gaskets, egr block off, everything. I wanted to run this finding by you all. In looking at my MSD 6al ignition box I decided to disconnect it. After disconnecting I hook up the coil normal, started it and the car will not idol at all. I tried it twice and both times the car fires and then quickly dies. Now. I hooked back up my MSD 6al ignition box, started and the RPMS race up to
3k. Only when I disconnect the MSD is when the car sounds like it wants to idol correctly but it quickley dies. The PCM I have has not been tuned yet. Everything on my motor is stock with the exception of a cam and stroker. So does this sound like a PCM issue. COuld that be why its not idling?
Chris

 

You need to get the PCM tuned to match the new cubic inches./mods. Your are more than likely going to need new larger injectors, too.

 

Well I was hoping I can get away with the stock fuel system. ON my previous 355 motor I ran the stock fuel system. But maybe your right. Cash flow is really bad right now. What do you think about the PCM tune in relation to my high idol and the MSD. I think there something going on there.
CHris

 

You'll need a PCM tune at the very minimum. The idle problem is because the airflow through the MAF does not match the stock airflow tables for idle. The cam doesn't help in that regard, either.

I'd contact madtuner.com... Ion does great work, and can steer you in the right direction.

 

To get the car running correctly, you don't need to upgrade your injectors or fueling. I ran a 383 with stock injectors and even road raced it that way.

You really need to get DataMaster or Freescan and see what is going on. Without this, you will find it next to impossible to determine what is going on. Further, to properly tune a 383, you need to scan.

 

Bishop I thank you. Ill be getting my tune done this week. Now switching gears here. Valve Covers.. Do you know who makes a taller valve covers for LT1's? My stock ones are too small and they dont clear my rocker arms.
Chris

 

You'll probably need to crack the throttle blades open a bit and then slot the TPS sensor screw and readjust to the correct voltage. Generally, strokers will need more air at idle. You also need to scan it and see where your IAC counts are at. They should be on the low side. Cracking the blades open and readjusting the TPS will get you there, but like stated above, you really need to scan it and see what things are doing.

Ken R.

 

With his larger cam, this will only cause split BLM issues to surface. The correct way to handle this is to close the blades all the way and to drill out the IAC bypass air passage bigger. Everyone ignores the fact that LT1 plenums have special passages for idle air and these must be taken advantage of to keep the car operating correctly at idle.

 

Well the first thing that im going to do is get the tune done. This is my second build on this 385. First (which was my first time) I didnt have the main bearings on right rods pistons etc.. However the motor idled fine. BUt i did have the correct tune as well. SO ill start with the tune and then go from there.
Thanks Guys
Chris