besides JP?

can a TPI pump maintain 28 lbs consistently?

my idle is going asynch with too low a pulse width. My current FP is 17 lbs with 80 lb injectors. i am thinking of swapping in 65 lbs and upping FP. or would that just cause the same problem?

just burned a chip to run open loop all the time so will try that first. i assume i will have about 13/1 at idle instead of 14.7/1 CL idle.

 

Going to a smaller injector and raising the pressure would probably leave you in the same position now. The thing that determins the PW is the actual flowrate of the injector.

 

Oh, you can also add in bias to the mean O2 volts. That will cause the ecm to target a richer AFR.

 

tunercat offers that and i have changed it to 14.3/1. i emailed them to determine how far off 14.7 can i change the constant and they stated "not very far". apparenly that sensor is engineered to run near 14.7. 13.7 may be outside its parameters.

did any applications prior to catalytic convertors use an 02 sensor other than wide band 02?

another thought is to use the WB02 i have and patch it into the ECU. Innovative i believe offfers that in its user manual. running OL seems the next step. chip is in glove box. tomorrow will drop it in.

 

The stock O2s switching points are around 14.7:1 but theres some wiggle room on either side. Running open loop just to raise the PWs also isnt the best solution, either. The best solution would be to use a VacAFPR and do a minor patch to the code so that you can have fuel pressure compensation. It would be alot easier then trying to have a closed loop wide band system.

 

This is a real possibility with the 8746. If your not going to be driving up into the rockies every day or something you can plow over the code for the baro correction. I took a quick look and that code is run at all times with a good stretch that has no external branches or jumps.

 

If you can find two consecutive mem. addresses you can also filter the BPW correction to match the response of the VacAFPR.

 

I've run the 350 injectors (org/blk) at 30 psi with no issues. A TPI FP can keep up with 28 psi fuel pressure as it is enough to feed a 350 at 43-47 psi (standard MPFI pressure).

As for the async mode, eliminate it by setting the switch points to zero. This is better then having it switch in and out. Fueling is more consistent. With this done the ECM will only use async mode for AE.

Could also set the switch points high and the ECM will always be in async mode. GM actually did this with some calibrations.

RBob.