I helped a friend put TBI in his T/A. He has a 224/230 .500/.510 Compcam, Sportsman II heads, 10:1 compression, 2" TBI w/ 90pph injectors.

It idles around 1000 rpm x 60 kPa. That much I expected. So I did the usual VE table by moving the "old" idle cells (600 x 30 kPa) to where it idles now...and lowered the idle AFR bias.

It idles ok now but the part throttle is terrible. It drives and everything but he has to use the "two foot" method. Something I didn't think about was the SES light. The ECM keeps throwing a MAP high code.

Is this something that has to do with the tuning? Or are we screwed and I need to learn source code REAL quick?

what have you done to tune the part throttle? if its a stock cal and you just moved things over its still gonna drive like ***

All I did so far was adjust the BPW for 90pph injectors @ 17 psi, and tune for a decent idle.

I suspect that I will have to lower all the VE values at low RPM...

My big question is what do I do about the SES light?

Can we get a datalog of it idling warmed up?

Why is it idling at 1000? What is commanded idle? Do you have the Parl/Nuetral switch working?

if you are at 60 kpa and 1000 rpm i think your tune is messed up or you have a vacuum leak you should have more vacuum than that

im thinking about the low map situation. Ive never run into that on my car except for when it was about to stall out or what have you and was just barely keeping it alive. Mine idles around 55kpa at 650 rpm

I have the gut feeling that once you figure out why its idling so high with such low vacuum.. and sort it out.. that code will dissapear. Try using a uniform number for spark advance around the idle area like 20 degrees.. how does the o2 look? able to get blms from it?

The BLM at idle is 128. Everywhere else I saw the BLM was 108. The O2 voltage showed the same results...too rich. The 60 kPa x 1000 RPM idle is in park. If you put it in drive it wants to die.

I have idle SA set to 26.02.

I also think I have the Accelpump vs. TPS set too high.

whats your bpw set at ?

btw with that setup its gonna want to idle much richer than stoic id try shutting off closed loop for now and just tune it for best idle

did you also ensure the pod is raised so that the injector spray cone is just hitting the edges of the blades? also, are you keeping the iac counts in check? the more air you can pass through the TBI tb rather than the iac the better this helps immensely with fuel distribution

Keep in mind that if you are using a scan tool then when you link to the ECM the idle will be forced to 100rpms (at least when using Diacom). What is the idle WITHOUT the scan tool linked to the ECM?

Tim

The BPW is set at 70. They are 90pph injectors @ 17 psi.

The injector pod does have a 1/4" spacer. I'll try opening up the throttle plates again, but it seems like that always raises the idle too high. Even if you adjust it with the car off.

We are using the 7747 ECM. I'm using WinALDL and it doesn't need any resistors to start sending data.

That sure seems like a lot of fp for 90lb injectors at idle, and probably to much for a cruise setting as well. You should check into a vafpr, this would a help get the pressure down at idle. Also do you have a way to pull about a 17" vacuum on the map sensor. This would trick the ecm into thinking the cam is near stock and cut the bpw down. Just a thought.

Steve