ih8chevy

Can I run em? My 86 is running lean with the heads I have on it, Im upgrading to a 70 mm tb/egr spacer and I am porting the gt40 intake to match the heads, and right now the car runs lean and I figure it wont get better with the porting mods. So my question is, how tempermental are 24 lb injectors with speed density?

**Edit** I forgot about the speed density section: Sorry

AdderMk2

you are going to injecting 20% more fuel. plan on cranking your fuel pressure down a few pounds. the car is probably going to run like crap for a few days until the ECM settles out the KAM

yzfr6i

It will be like running 24lb injectors in a mass air car that still has the 19lb sampling tube in it. Your O2 sensors will try to lean it out, but the computer can only shorten the injector pulse so much. And a WOT the O2s won't have any control and it may be quite fat.

Just a note.. Speed density cars run a bit lean even when stock. That's why stock vs stock a speed density car makes more power than a mass air car. What other mods do you have done to your car? I had an 88GT with quite a few things done and never had a problem running 19lb injectors, and I had the timing set quite hight. I believe 18 deg base.

Joel5.0

How do you know it's running lean?.... did you run the self tests and got lean code failures from the ECM? You need to ID what's causing the ECM fuel trim to fail.LUK