hey guys. new to third gen and to tbi.

my dad has a howell tbi setup in his jeep and recently installed a new sbc 350. apparently the cam has too much overlap and is causing the vacuum to drop to about 13psi at idle. i know that this is affecting the map. it will stumble and stall while in park. is there something in the .bin i can change to over come this problem? the computer is the 7747 and 42.xdf. the system does not use the distributor control or vss. i am also in the process of installing tbi on my jeep and am expecting to have the same problem.

thanks

 

Getting the idle rpms higher should help. It likely needs some timing and fueling adjustments, usually needs quite a bit more timing when idling with a larger cam. I see you said you don't have distributor control. Try physically turning the timing up about 8 or so degrees just to see if that helps at idle. I wouldn't suggest going WOT with it turned up, just do it to see if it helps the idle and part throttle.

 

You need to locate a datalogging cable and complete a log of engine operation. You can use winALDL or Tunerpro RT. As you state first step is to address fueling at idle (and off idle under load). Logs to be done with steady throttle on level road to start.

You may want to look at a SA table for a GM 1/2 ton pickup with auto trans using its curve. Keep in mind there may be "adders" for WOT in that .bin. that .bin is located at craigmoats under downloads. It can be opened with TunerPro.

 

ok. thanks. im currently working with moates to get all the hardware needed to complete the task.

 

ok i just ordered the apu1 and a few chips