Veetail88
Well Known Member
I hang my head in shame before you all to let you know that I’ve reaffirmed what I know to be true about having others go over your work.
Over the past few weeks I’ve been running a thread about some problems I’ve been having with my brand new motor. From first start it hasn’t been running right and I’ve tried a lot of things trying to solve it.
I ended up with two problems. One, the motor was running rough. But not always. It would run fine at maybe 1700 RPM, and after several seconds it would choke and shutter for a bit, then start running fine again for several seconds and repeat. The other was low pressure from the mechanical boost pump.
I explored some of the ideas that came in from the VAF brain trust. I verified the mechanical pump was indeed the high pressure model required for fuel injection. I ran the motor with the red cube bypassed; I ran the motor with the mechanical pump bypassed. I checked the fuel lines for a loose fitting or b-nut, I checked the fuel filter for debris along with all of the fuel lines FWF and found nothing. I even removed the fuel pump and tore it apart looking for something wrong in there. Still nothing.
I had plenty of fuel pressure with the boost pump on and the engine still ran rough so I assumed I had 2 separate problems. I surmised that for sure the mechanical pump was bad at least, and that I had a separate problem that still needed discovery.
Well I finally fixed it all last Sunday and the problem was me.
When I made up and assembled the fuel lines from the fuel selector through the filter and boost pump, I torqued all the b nuts and put a dab of torque seal on them, so, when “many” others on this site suggested I might have a loose fitting, I checked every one of them…….that didn’t have torque seal on them.
So last Sunday, after unsuccessfully fiddling with things for what I’d determined was the last time, I was going to pull the fuel pump back off, send it out to be tested/overhauled and shelf my motor problems until spring. I then decided I would go through all the fittings one more time, starting at the tanks and going all the way through to the injectors but this time, I’d check even those I “knew” to be tight.
You would be surprised how well that motor ran after I found that loose nut! You know, the one with the torque seal on it? Sheesh! What a dummy.Incredibly the mechanical fuel pump is producing 20 psi at idle and more at higher speed, and the motor isn’t stumbling and choking anymore! Idling real smooth now too!
So the moral of the story is the same one that is preached here all the time, and I hope I’ve learned it well. ALWAYS have 1 or more people put a wrench or screwdriver on EVERY nut, bolt, screw, etc. on the airplane!
Hope I’ve taught me a good lesson!
Over the past few weeks I’ve been running a thread about some problems I’ve been having with my brand new motor. From first start it hasn’t been running right and I’ve tried a lot of things trying to solve it.
I ended up with two problems. One, the motor was running rough. But not always. It would run fine at maybe 1700 RPM, and after several seconds it would choke and shutter for a bit, then start running fine again for several seconds and repeat. The other was low pressure from the mechanical boost pump.
I explored some of the ideas that came in from the VAF brain trust. I verified the mechanical pump was indeed the high pressure model required for fuel injection. I ran the motor with the red cube bypassed; I ran the motor with the mechanical pump bypassed. I checked the fuel lines for a loose fitting or b-nut, I checked the fuel filter for debris along with all of the fuel lines FWF and found nothing. I even removed the fuel pump and tore it apart looking for something wrong in there. Still nothing.
I had plenty of fuel pressure with the boost pump on and the engine still ran rough so I assumed I had 2 separate problems. I surmised that for sure the mechanical pump was bad at least, and that I had a separate problem that still needed discovery.
Well I finally fixed it all last Sunday and the problem was me.
When I made up and assembled the fuel lines from the fuel selector through the filter and boost pump, I torqued all the b nuts and put a dab of torque seal on them, so, when “many” others on this site suggested I might have a loose fitting, I checked every one of them…….that didn’t have torque seal on them.
So last Sunday, after unsuccessfully fiddling with things for what I’d determined was the last time, I was going to pull the fuel pump back off, send it out to be tested/overhauled and shelf my motor problems until spring. I then decided I would go through all the fittings one more time, starting at the tanks and going all the way through to the injectors but this time, I’d check even those I “knew” to be tight.
You would be surprised how well that motor ran after I found that loose nut! You know, the one with the torque seal on it? Sheesh! What a dummy.Incredibly the mechanical fuel pump is producing 20 psi at idle and more at higher speed, and the motor isn’t stumbling and choking anymore! Idling real smooth now too!
So the moral of the story is the same one that is preached here all the time, and I hope I’ve learned it well. ALWAYS have 1 or more people put a wrench or screwdriver on EVERY nut, bolt, screw, etc. on the airplane!
Hope I’ve taught me a good lesson!
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