Originally Posted By: tlowe #1716
I found with mine the bog went away when I adjusted the "pump shot" or acceleration enrichment to be less. That was with the turbo EFI 292.

Being as there is not throttle position sensor it's extra sensitive to having the VE table tuned exactly right for the pump shot. Admittedly right now the pump shot is extra heavy because when I first got the car running I had a bad lean pop when I'd stomp on the throttle, and a big pump shot stopped that. I have reduced the size of the pump shot significantly since I first got it running, but I'm at the point I need to spend more time in the low vacuum/low rpm part of the fuel table before I can reduce it any further. The only time the engine operates in that part of the table is when stomping on the throttle from a stop, so I just have to dedicate some time to doing that and making adjustments.

 Originally Posted By: efi-diy
When you do go turbo remember that the available torque is non-linear. This causes issues with line pressure - with out being able to reference the line pressure to boost - you end up running high line pressures.

The other end is torque converter selection - you may want to wait to select the stall speed until you know where the boost will kick in...

The fuel pressure regulator is vacuum/boost regulated. I have a vacuum line going to it currently. I'm thinking I will probably engine dyno the the turbo engine prior to install to know better what it'll do.

The layout of the fuel system will change significantly for the turbo engine (moving the whole fuel system to the driver's side, and off the firewall), but I'll be using the same regulator.

Thanks for the suggestions.

Edited by TheSilverBuick (03/16/14 07:16 AM)
Rebuilding an OHC Pontiac 250 with EFI and a Turbo