Quote:
Originally Posted by Formulajones
One thing about these EFI units when fuel pressure issues arise, you can't really tell just by the afr gauge.
These systems will compensate for a weak fuel pump and continue to add more fuel to meet your target afr. You need to look at a datalog to see it. Or look in the tune. You'll see things like the learn table going nuts in the wot areas adding a ton of fuel and it will continue to add fuel up to where ever you have your compensation limits set. Once you reach that threshold it will stop adding fuel and if it's not enough then of course the nose over sensation or lack of rpm.
These EFI units are good at masking fuel issues depending on how you have the tune set up
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Yes, that's why I'm getting a gauge on it. I also need to run a datalog, but I'm a bit fearful of doing so incase something more major is occurring. I did notice last week that the system was struggling to maintain AFR at idle for a couple minutes. It would hunt to mid 15's where it's usually rock steady around 14.3. It cleared up after though. This could be a symptom that I was overlooking.
Quote:
Originally Posted by steve25
If your hearing no valvetrain noise at hot idle I can't see any darn reason for suspecting worn Hydro roller lifters.
I have heard of conical springs breaking though.
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The valvetrain I have in the engine has always been very noisy. I've long attributed it to the aggressive cam lobes, the fact that the engine doesn't produce a great deal of warm idle oil pressure (typically around 15psi) and the Lunati lifters which are known to be noisy. What I have started noticing however is that they have started to clack more recently and even off-idle. Once oil pressure comes up off idle, they tend to quiet back down and you hear the HS roller rocker's sewing noise instead.