Ive been playing around with the scaling of the 550 injectors and Ive been getting a P300 [ multipal miss fire ] No biggy...think I found the salution for that . But I did get a P1574 code today . My OBDII didnt have a name for that code . Any one know what it is ?
Thanks Bill

 

P1574

 

Sorry it is so small but they have really reduced the sizes of the pics allowed, so I can email it if yo uwant email me at gusm@sfzcc.com

 

Thanks...I was able to read mosst of it and it gave me a good idea

 

booger, you said you found the reason for the P0300 code? Is there a way to stop that code from coming back on?

 

John Isbell from grubb's seems to think that if I take out 2 degree's of timing advance the ECU will not react like there is a lean idle and start with the 550 injectors . Hopeing to get that done today

 

Let us know if that works. I think we have all seen that code. 2 degrees seems like quite a bit, but the results will be interesting.

 

I took that 2 degree's out with the Split Second box [ across the whole vacuum and boost timing map ] . So far the starting and idle is MUUUUUUCH better . Under vacuum the A/F is much more stable . So I think that will do the trick . Going to the Dealer Friday to take it out in the ECU and have them run the a ....air / idle learning procedure . Last night the car went into a limp mode . I had never had that happen and I though the car was -ucked up . Reset ECU this morning and all is well....and getting better

 

Yeah, the limp mode thing is scary. You should try it at 80mph on the highway. It is like slamming on your brakes! I will be doing the idle learning procedure as well due to cams and reduced compression.

 

I was on the highway , only doing 60 though . It kept running but was pig rich and would die when I came to a stop

 

That's because scaling your injectors that much makes the ECU think the motor is getting a lot less air coming in. Less air = more required timing advance. Scaling injectors like that just modifys the MAF signal to trick the ecu into scaling down the duty of the injectors, but at the same time causes an excess of timing advance.

 

That's because scaling your injectors that much makes the ECU think the motor is getting a lot less air coming in. Less air = more required timing advance. Scaling injectors like that just modifys the MAF signal to trick the ecu into scaling down the duty of the injectors, but at the same time causes an excess of timing advance.


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That explains why my tune on the boost side of the fuel map is way off now . I had it some what acceptable to 6000rpm . Now its lean , cant even take it pass 4000rpm now . I have to take it out today and do some tuning