Settings for my new injectors

**asshanson** · 03-18-2008

I bought some used PTE 880s yesterday (Aaron's from last year), got them installed last night (in the snow), but the car was having idle problems. I figured I just had to adjust the AFC since they're decently bigger than the 660s I had before.

I take out 20% fuel because it was really rich, but then the A/F ratio on the wideband goes really lean. So I change it to -10%, ratio goes to 14/1 for awhile, then gets lean again. Now I have it at 0% for 1000rpm which is what it was at for my 660s before.

When you first install injectors, does it take a few minutes for them to break-in or get used to having fuel in them again? Also, why is the correction factor almost zero at low RPMs for the bigger injectors?

EclipseGST · 03-18-2008

What else do you have for tuning?

880s are a little big for the AFC in my opinion unless you have something else like GM Maft or chip to compensate for the larger injectors, then just use the AFC for fine tuning.

Did you make sure your fuel pressure is 43.5psi base?

**scheides** · 03-18-2008

It will be next to impossible to get those to work properly without dsmlink or aem. Stock injectors are 450, 880 is roughly double that, and the S-AFC can only do 50% changes, not 100%.

As far as idle is concerned, larger injectors usually need to have the afc set to zero or even a positive value for the very lowest rpm setting. Try setting it to +10 or even +20 and see if it will at least idle.

**JET** · 03-18-2008

I would get an Eprom ECU and have Shane burn a chip for you. You can get other goodies also.

**asshanson** · 03-18-2008

thanks for the info guys. This was just temporary until I get my ecu and link back from MAP. I got it working though, my ecu corrected pretty quickly and my mileage is about normal (currently driving to Iowa).

turbotalon1g · 03-18-2008

^sweet sorry man, i forgot to call u back, last 2 days have been nuts

**scheides** · 03-19-2008

So ahhh, you swapped your injectors, they did not run right, and then you decided to just drive to Iowa? Seriously man, how long are you planning on keeping your car running? Take better care of it man, you are ASKING FOR TROUBLE!

A//// Guy · 03-19-2008

lol thats the dsmer way :P

**asshanson** · 03-19-2008

No I made sure it was running right before driving to Iowa. I had some time to get it right before I left.