GEM930

GEM930

Well Known Member
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I have posted several times in the past in reference to trying to figure out some climb and tuning issues on my electronic fuel injected O-320 H2AD. Still working on it, but things seem to be coming together. I was hoping anyone with a FP O-320 could let me know what their fuel flow is particularly on climb. I'm never seeing more than 10.5 g/hr. Per my manual this seems low. I have checked to make sure the throttle body is opening completely and it is. The system is equipped with an air fuel meter that indicates it is not going lean, and temp seem to confirm this. Seems to run great but as I have posted before the climb is poor and fuel flow is only around 10.5 WOT.

Anyone care to share their fuel flows???

Thanks

GEM
 
GEM930 said:
I have posted several times in the past in reference to trying to figure out some climb and tuning issues on my electronic fuel injected O-320 H2AD. Still working on it, but things seem to be coming together. I was hoping anyone with a FP O-320 could let me know what their fuel flow is particularly on climb. I'm never seeing more than 10.5 g/hr. Per my manual this seems low. I have checked to make sure the throttle body is opening completely and it is. The system is equipped with an air fuel meter that indicates it is not going lean, and temp seem to confirm this. Seems to run great but as I have posted before the climb is poor and fuel flow is only around 10.5 WOT.

Anyone care to share their fuel flows???

Thanks

GEM
Click to expand...

Electronic fuel injection with Lycoming is extremely rare. Your reference to it is the first I've read hear but that doesn't mean there aren't EFI's on board other than with auto engines.

Seems like a good source for information regarding your situation would be the person who invented the system for your airplane. Low fuel flow with pulse timed injection usually means low fuel pressure or something not right with the computer running the show.
 
I get about 13 or so. I'd like to re-jet my carb at some point to up that to about 16 or 17. It is my understanding that you should see approx 10% of your HP in FF.
 
WOT T.O. fuel flows

In an article I recently read on AvWeb, the rule of thumb for WOT, take-off, full rich, fuel flow should be:
8.5 to 1 compression ratio (requiring 100LL fuel): 9% of rated power (ex. 160 hp min fuel flow is 14.4 gph)
7 to 1 compression ratio (80/87 fuel): 10.5% of rated power (ex. 150 hp min fuel flow is 15.7 gph)

These minimum flows are required for engine cooling to prevent detonation. You should see MAX EGT's under these conditions of around 1300 and MAX CHT of 400. Temps greater than this indicate risk of detention and can be corrected by reduction of power or setting your mixture to meet the flows above.

My IO-320 D3G runs 16gph, EGT range is 1270 to 1320 and hottest CHT is 390.

The author of the article insists that if you meet the minimum fuel flow at takeoff, you should NOT throttle back or run the prop back during your climb out. Instead, continue your climb to altitude and slowly begin leaning, as you climb, to maintain the same EGT that occurs during your initial climb out of the pattern.

Frankly... it makes a lot of sense to me.
 
David-aviator said:
Electronic fuel injection with Lycoming is extremely rare. Your reference to it is the first I've read hear but that doesn't mean there aren't EFI's on board other than with auto engines.

Seems like a good source for information regarding your situation would be the person who invented the system for your airplane. Low fuel flow with pulse timed injection usually means low fuel pressure or something not right with the computer running the show.
Click to expand...


The system is built by Tracy Crook at Real world solutions. Originally designed for madza rotary aircraft engines. Due to demand he started producing systems for subys, chevys, and Lycoming and Cont. ... While he is very helpful, he is primary a Mazda guy. That's why I was looking for FF numbers to try to get it tuned correctly. The system runs great. The engine has never died, not even while tuning on the ground during the initial tuning. Ran smooth pretty much out of the box. Except for some of my wiring mistakes). My top speed has increased from 183 to 192 (MPH), but I seem to be missing something on the climb. That's what I'm trying to track down. Everything runs great on the climb, but my numbers are lower then they were before the switch to EFI. FF at 10.5 seems like it might be the problem, but it does not seem to be running lean.
 
My 125 HP O-235 runs as much as 9.5-10.5 gph in a 2400 rpm climb at low altitude. Maybe your throttle valve isn't opening all of the way or your FF indicator or sensor is wrong.
 
Automatic leaning??

Does this EFI system have automatic / computer controlled mixture? Or is the mixture all manual control?

If the mixture is computer controlled, then it may well be a software issue.
 
The system is shipped with a basic fuel map loaded. You then adjust the injector flow rate to match your engine/injector combination. For fine tuning, the system allows you to adjust the fuel map at 128 locations based on rpm and manifold pressure. There is a mixture control, however it is used more to adjust between economy and power settings. The computer will maintain whatever fuel map that has been programmed. The mixture lets you increase or decrease fuel at whatever setting it currently is at. Again, the engine runs great at all settings. The system also controls ignition. I keep thinking the ignition is the key. If the ignition is retarding too much at WOT wouldn't that cause the engine to produce less power? Less power..less manifold pressure....less manifold pressure... the computer will supply less fuel. I'm sure I'm over simplifying things, just running out of ideas.
 
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