Nozzle spray angle...

[jondee86]

I am attempting to resolve a tip-in misfire that can be seen here...



When starting to accelerate, TPS movement invokes some "throttle pump"
enrichment, and the increase in injector duty cycle triggers the WM injection.
This appears to cause a rich misfire that shows as a lean spike in the AFR.
My WM injection initiates at around 10% IDC as in the absence of an inter-
cooler, I use WM for charge cooling once the car reaches around 110 kph
while cruising.

I have a number of adjustments for both fuel and WM injection, and to help
with getting the balance right, it would be nice to be able to log the actual
onset of WM injection and the rate of injection.

From reading the HFS-2/3.1 manual I gain the impression that if I use the
Green Harness I should be able to output a 0-5V signal from my HFS-3 to
a spare 0-5V analog input on my ECU.

EDIT: OK, looks like the yellow wire on the green (USER) plug should give me
the information I require, so I will go with that.

Can someone please confirm that my understanding on this is correct ?

Cheers... jondee86

[jondee86]

Got the flowmeter output in my logs now, and it shows me when the WM
injection triggers and how the flow varies with rpm. Now I can fiddle with
the various trims available to adjust bothe the trigger point and injection
rate to try and get a better match to my fuel injection IDC graph.

Finally managed to find a decent OEM bypass valve (off a turbo Legacy)
that I could modify to fit my Bosch based bypass pipework layout. Should
allow a bit more air to flow when out of boost, which should in turn help
my out of boost cruising manifold air temps. Will be testing this in the next
couple of days to se if it performs as expected.

Cheers... jondee86

[jondee86]

New bypass valve is up and running...



Works great and seems to pass a bit more air than the old system, so I am
having to re-tune my VE map below 85kPa. Engine pulls hard all the way to
my 8000rpm redline with virtually no dropoff in acceleration. I am considering
getting a 65dia s/c pulley to replace the 75dia pulley I have at the moment.
This would mean dropping my redline to 7000rpm to avoid overspeeding the
s/c but I don't see this as a problem. It should help the engine live longer.

Currently I am chasing the misfire that I get when I accelerate hard in any
gear from around 2500rpm. It only happens once about a second after I hit
the throttle, and I have not noticed any misfiring further up the rpm range.

Bearing in mind the earlier comment made by rotrex about spray killing the
spark, I did wonder if that might be the problem. Hard acceleration at around
2500rpm invokes extra enrichment and also triggers the W/M spray. But when
I switched off the W/M spray the misfire still occured, so now I am adjusting
the enrichment tables to see if I can find an answer.

Cheers... jondee86