Quote:
Originally Posted by cleatus12r
Actually it would be really easy to do in ANY tune. The EOT-based SOI map would easily allow that to happen.
Your thinking regarding an actual TUNE would work too and wouldn't be too hard to do. When I get home tonight I'll post up some ideas for you.
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Looking forward to your input.
I'm thinking a tune that has the SOI advanced beyond what is safe to drive with, but without harming the engine at idle or no-load fast idle.
Hence the need for an RPM limiter to remind you to switch away from that tune for driving.
What brought this idea to mind is working with the older VW mechanical injection diesel.
They have a "choke" knob that you pull to advance the pump timing a little. If you don't pull that knob the engine smokes like crazy, if it starts at all, and really struggles to idle. Pull the knob and it instantly clears up, idles smooth and all the smoke goes away.
Pulling the knob makes a difference in how the engine sounds when warmed up, the engine gets louder at idle.
This behavior is consistant for every one of those engines from brand new rebuilt on down to a worn out beater that still has decent compression.
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My new engine in the truck is behaving the same way, as if it needs more SOI when cold compared to the old engine.
Switching to the 1100 rpm fast idle doesn't clear it up, it just raises the engine rpm.
The diesel clatter is also muffled under the excess fuel loading when cold as large clouds of fuel smoke as blown out of the tailpipe.
It will smoke for a long time, much longer than the old engine did.
If I drive away immediately, (gently) it clears within 1/4 mile and sounds normal.
I don't know what changed between the two, I re-used all the temperature sensors off of the old engine.
The new engine came with a new ICP sensor and a CMP sensor, but I have a hard time seeing where those two would make a difference in this case.