FOUND IT ! My CFI, Norm found the reason why the engine was cutting out, THANK GOD! Come to find out, the SDS Computer has two ground wires, one is for the fuel injectors. That ground was placed on the top strut mount where the coil over shock is attached to the frame. Now we tested that ground several times and it always tested good. But Norm surmised that it might change change as the pressure on the suspension changed when lifting off. We rewired the ground wire directly to the neg terminal on the battery and no more cutting out.
Thanks to everyone who replied. Check those ground wires! One good thing to come out of all of this frustration is that I know my trike much better now than I did two weeks ago. I am also having an over heating problem, but will start another thread for that.... Thanks again....
Thanks for the suggestion. Checking all the wiring was one of the items I had on my list. The computer would registre and ERR message where is displays the rpms if it lost power and had never done that. Plus, the engine never completely never shuts off, just loses power and goes to idle. My CFI says that these Suzuki G13B engines are really well suited for this type of aircraft as well. Thanks again. -Bruce
I had a problem once with a battery powered sensor that was running around a production line. One of the machines was lifting it so fast the spring under the battery was compressing under the weight of the, not very big, battery and the positive terminal was being disconnected. Neither the the SDS system or the G10 are that uncommon in aircraft applications so its hard to believe that its a fundamental design problem.
__________________
1984 Suzuki SJ413K pick up, 1.6 16V Baleno engine 2000 Suzuki Vitara 1.6 8V, many mods 2004 Suzuki Ignis 1.5VVT 4Grip 2006 Suzuki Jimny 1.3VVT JLX+ and many more.
Thanks for the response. What I meant was that engine does not stall, like an electrical short would cause, it just loses all power, like it ran out of fuel. The trike has both a foot throttle for take offs and landing and a hand trottle for cruising. We are using the foot throttle....
-- Edited by Raptoraddict on Thursday 16th of May 2013 10:58:25 PM
Sorry, I made an error in my last post. One fuel pump is in the tank, the second is "t'ed" into the same line which feeds the motor.... The problem exisits when just running one or when both fuel pumps at the same time. -Bruce
Thanks, we thought about the angle as well. I found a mobile mechanic that is willing to come out on Saturday to check the fuel pressure at the fuel rail (multiport fuel injection) at all different rpms. I will be bringing blocks of wood as well so that I can set the trike up at different angles for the test as well (basically what you suggested). Both fuel pumps are in line (no surge tank). I am also going to check to make sure that they are powered by completely different circuits incase I am getting some sort of short at take off. I am really hoping that it is the fuel pressure regulator on the end of the fuel rail that is operated off of manifold vacuum. Just a tiny hole in that membrane would cause all sorts of diffuculties, but I will let an expert determine that.
It seems to have something to do with the forces of accelleration or the angle of take off. I will also recheck all the wiring to see if anything is chaffing....
I will be sure to update this post after the mechanic checks it out on Saturday.
I think I'd be looking at the fuel pressure first, from what I recall the SDS ECU is a rather basic design, have you got a Wide Band O2 sensor? that would be useful for checking that you're not going lean at full load.
__________________
1984 Suzuki SJ413K pick up, 1.6 16V Baleno engine 2000 Suzuki Vitara 1.6 8V, many mods 2004 Suzuki Ignis 1.5VVT 4Grip 2006 Suzuki Jimny 1.3VVT JLX+ and many more.
What's the possibility that the problem is related to the "angle" at which either the engine or the aircraft is at?
Presumably an ultralite has to rotate to a "nose up" attitude as it reaches the end of it's take off roll.
The other possibility I can think of is a restricted fuel supply - fluid dynamics is a very complex topic - but, in a nutshell, the pumps, both of them, need to be able to supply, enough fuel (quantity) at enough pressure - with most pumps, the two are inversely related, as the delivery volume increases, the available pressure decreases, and vice versa.
Is the second pump just "inline" with the first or is there a surge tank in between them?
Thanks. Yes, I have called SDS and have gone through all the parameters with them and they say it all looks good. I will attach pictures if I can figure it out
I just bought an APEX two seat untralight with a 99 Suzuki Swift 1.3l FI engine, rated at 95 hp. The motor was taken out of the car, completely gone through by a reputable machine shop and had an SDS ecm installed to replace the factory ecm. The motor only has 44 hours since the rebuild and it has two fuel pumps, one in the tank and an external (in line) pump. When tied to the floor, the static engine will run flawlessly at any speed for any amount of time without any issues, but when we are taking off, just as we are at the end of our take off roll or have left the ground, it the engine loses power (the worst possible time) but does not stall. It will again run flawlessly once we have stopped accellerating and we can not replicate the problem in any other configuration. I have taxied it for over an hour at varying speeds and it never misses a beat. But it has cut out three time on take off (it is a much longer accelleration than just taxiing) and I am about to go crazy. I am not sure why acceleration would matter, but it seems too. Any suggestions would be greatly appreciated. Let me know if you need any additional information. I am currently in Flagstaff AZ and the trike is in Casa Grande where I am taking lessons -Bruce
