4A-GE with 264º HKS Camshafts running very rich

[apardal]

Well, you've managed to mess my mind up! Now I'm even more confused.

What I know is:

About compression
- I have longer duration cams, shaved head and trd head gasket, so compression values are fairly stock which I think is Ok.

About AFR
- Longer duration cams means that the map sensor will read lower pressure in the intake manifold. The ECU thinks the engine is on heavier load and will respond with later ignition and longer injection which makes it run richer. Running too rich will make the mixture burn slower, hence losing power.

(all these sentences are suppositions of mine, I'm no expert on this matter so please correct me if I'm wrong)

Solutions:

- The CO (lean/rich) screw only acts below 3600 rpm so it won't make any difference in high rpm's.
- Having a fuel pressure regulator or smaller injectors will act in all rpm range proportionally and that's not the perfect solution. I think I'll need differential changes throughout the rpm range.
- The SAFC seems like the best solution, although I do not quite understand what Zdoman is stating to be the downside of going with a piggy back.

Recently I've found that the Greddy E-Manage Unit is quite complete... but I don't know anyone who has experienced it with 4A-GE's.

I would also like to change my rev limit, since these cams need a little more rpm... but megasquirt is a long way to go and I don't know other solutions that may fit my requirements.

Thank you very much for your interest

Best regards