New Engine installed - no fuel pressure.

[Igor_U]

So, we installed the Rebuilt engine in my '67F. 

Ground run last weekend was successful with leak and failed Alternator indication fixed but the Engine monitor (CGR-30P, 3-4 years old) was showing zero pressure. EI support suggested they rarely go wrong and to test it with "calibrated pressure", using compressor. I ordered a new unit, just in case as it's been too long of a wait for the engine, parts and installation.

 

Installing new pressure transducer didn't solve the problem; flipping fuel pump switch would still show zero or maybe (in some instances) up to .5 psi. Engine would start with no problems and run (even at higher rps) showing zero psi fuel pressure. Applying air pressure would show 29psi (compressor set to 30-ish). Same with the old transducer I re-installed back. 

I tested the full line, from spider to transducer on firewall including reduced orifice fitting on the spider. I would blow the compressed air through it and the new fuel hose and engine monitor would show pressure in green. But when we run the engine or electric fuel pump indicated pressure is 0psi. We confirm fuel gets in line and to transducer (not that it matters as air would be pressurized a well).

My IA and I think it must be spider but not sure. I'll talk to Factory on Monday but to get someone to return your call is hard with Lycoming. I am still waiting for a return call when I ordered the engine. 

I would like to here what you guys think and what to suggest. What to test? It doesn't seam IA can open the spider (legally) and then is the warranty to deal with.  Removing and sending that out would be easy, fuel servo much more disrupting.

One more thing: could it be the hole shown at the bottom of the thread in spider is blocked by the fitting? It shouldn't but I didn't really measure it...

Regards,

Igor

 

 

[Ragsf15e]

Sorry to hear you’re having to deal with this.  Definitely sounds like it’s something related to the engine and not the line or sensor.

Curious though… where is your fuel pressure line connection?  Mine is on the top/back of the fuel servo, right behind the air intake.

[EricJ]

If you have access to a known good gauge, connect it at the same place on the flow divider and see if it sees pressure.   Another thing to check is the electrical grounding of the transducer and if that differs between your open test and when it is connected to the divider (e.g., is the divider grounding the transducer through the braiding on the hose).

 

[PT20J]

1 hour ago, Igor_U said:

So, we installed the Rebuilt engine in my '67F. 

Ground run last weekend was successful with leak and failed Alternator indication fixed but the Engine monitor (CGR-30P, 3-4 years old) was showing zero pressure. EI support suggested they rarely go wrong and to test it with "calibrated pressure", using compressor. I ordered a new unit, just in case as it's been too long of a wait for the engine, parts and installation.

 

Installing new pressure transducer didn't solve the problem; flipping fuel pump switch would still show zero or maybe (in some instances) up to .5 psi. Engine would start with no problems and run (even at higher rps) showing zero psi fuel pressure. Applying air pressure would show 29psi (compressor set to 30-ish). Same with the old transducer I re-installed back. 

I tested the full line, from spider to transducer on firewall including reduced orifice fitting on the spider. I would blow the compressed air through it and the new fuel hose and engine monitor would show pressure in green. But when we run the engine or electric fuel pump indicated pressure is 0psi. We confirm fuel gets in line and to transducer (not that it matters as air would be pressurized a well).

My IA and I think it must be spider but not sure. I'll talk to Factory on Monday but to get someone to return your call is hard with Lycoming. I am still waiting for a return call when I ordered the engine. 

I would like to here what you guys think and what to suggest. What to test? It doesn't seam IA can open the spider (legally) and then is the warranty to deal with.  Removing and sending that out would be easy, fuel servo much more disrupting.

One more thing: could it be the hole shown at the bottom of the thread in spider is blocked by the fitting? It shouldn't but I didn't really measure it...

Regards,

Igor

 

 

The fuel pressure gauge is supposed to be connected to a port at the inlet on the servo to measure pump pressure. The port on the flow divider marked GAGE measures nozzle fuel pressure and is intended to be connected to a fuel flow gauge (fuel flow is proportional to nozzle pressure).

Skip

[Igor_U]

1 hour ago, PT20J said:

The fuel pressure gauge is supposed to be connected to a port at the inlet on the servo to measure pump pressure. The port on the flow divider marked GAGE measures nozzle fuel pressure and is intended to be connected to a fuel flow gauge (fuel flow is proportional to nozzle pressure).

Skip

Skip and all,

the old engine servo had a port and that is where i had a pressure transducer connected to with 38” hose. When engine monitor was installed, transducer was attached to the firewall and hose was connected  it worked well.

the new servo is different (Avstar LFR-NN555) and it didn’t have obvious port for the gage so we connected it to the spider. No instructions came with the engine.

it seems we need to look for a port on servo.  Will report back… 

[David Lloyd]

As Skip said, the GAGE port on the flow divider would read fuel pressure to the injectors, a much lower pressure and variable with flow, not the place you want to connect.  There is a port somewhere on the servo to show inlet pressure.

[Guest]

5 hours ago, Igor_U said:

Skip and all,

the old engine servo had a port and that is where i had a pressure transducer connected to with 38” hose. When engine monitor was installed, transducer was attached to the firewall and hose was connected  it worked well.

the new servo is different (Avstar LFR-NN555) and it didn’t have obvious port for the gage so we connected it to the spider. No instructions came with the engine.

it seems we need to look for a port on servo.  Will report back… 

Hopefully you saved the fitting from the old fuel servo.  The pressure fitting has an internal restrictor and is a special Mooney part.  
 

Clarence

[Igor_U]

Clarence,

unfortunately not as my engine was sent for OH but then we decided rebuilt would be more cost efficient.  Spider came with restricted fitting that possibly we can use.

Would you know the fitting p/n? Manual says p/n 610120 but doesn’t show the part on a drawing.
we just didn’t see a port on a fuel servo where to tap into but it seems it is at the plug that needs to be removed.

 

[PT20J]

The AvStar is a knock off of the RSA design. The Lycoming factory seems to have switched to AvStar — that’s what come with my factory rebuilt. Here’s the Mooney part. 

[Igor_U]

Just now, PT20J said:

The AvStar is a knock off of the RSA design. The Lycoming factory seems to have switched to AvStar — that’s what come with my factory rebuilt. Here’s the Mooney part. 

 

Thanks for the picture.

My 67 Manual has only a schematics with no pictures of the part.Iit seems it's the same part for all IO360 installs (E, F, J) and is replaced by p/n 940178-1. Both parts show "out of stock" at LASAR. This might be final delay... 

I did receive few fittings from the shop I sent engine to for OH, but I don't remember having that one. I'll have a look. 

Regards

[Guest]

The fitting for the flow divider(spider) is tapped for a 1/8" NPT thread.  The fitting in the servo id tapped for a 7/16-20 straight thread for a -4 fitting.  The fitting itself is -4 thread but the hose end is for a -3, plus it has the internal restrictor.  I never send an engine away with fittings,  they seldom come back.

Clarence

[Igor_U]

Just now, M20Doc said:

The fitting for the flow divider(spider) is tapped for a 1/8" NPT thread.  The fitting in the servo id tapped for a 7/16-20 straight thread for a -4 fitting.  The fitting itself is -4 thread but the hose end is for a -3, plus it has the internal restrictor.  I never send an engine away with fittings,  they seldom come back.

Clarence

Yeah,

I'll file this to "lessons learned" folder. For my next overhaul... 

[Guest]

Just now, Igor_U said:

Yeah,

I'll file this to "lessons learned" folder. For my next overhaul... 

Pass this to your maintainer!

[PT20J]

It was certainly an advantage to have the core when we got the rebuilt because we could put them side by side. My IA had swapped a lot if engines, but never on a M20J and there are some things that are only obvious in hindsight.

You know the old saying about people like @M20Doc: Turning the wrench, $1.00. Knowing which bolt to turn, priceless.

The out of stock indication on LASAR’s site just means that it’s not on their parts shelf, but it may well be in the factory’s inventory, so give Dan a call tomorrow. LASAR bought out the parts inventories of some former MSCs some time ago and so they had a lot of inventory. But, they told me that they don’t intend to stock that much stuff going forward.

Skip

[Igor_U]

Morning,

So it turns out that good people at Progressive Air did send the restrictor fitting back to me before shipping engine to the Lycoming. We managed to installed it and connect the hose without removing the lower cowl (PITA on M20F with Ram air) so I flew my plane for 2h above Paine Field to break in the engine. It was busy in the pattern (great day for flying at PNW) but controllers were nice about it and pointed the other traffic so I could pay the attention to the engine monitor.

Engine ran great with CHTs in 75% cruse at about 350F and oils temp at 185F.

Attached is the race track from Flight aware.

 

Thank you.

 

 

[Ragsf15e]

6 hours ago, Igor_U said:

Morning,

So it turns out that good people at Progressive Air did send the restrictor fitting back to me before shipping engine to the Lycoming. We managed to installed it and connect the hose without removing the lower cowl (PITA on M20F with Ram air) so I flew my plane for 2h above Paine Field to break in the engine. It was busy in the pattern (great day for flying at PNW) but controllers were nice about it and pointed the other traffic so I could pay the attention to the engine monitor.

Engine ran great with CHTs in 75% cruse at about 350F and oils temp at 185F.

Attached is the race track from Flight aware.

 

Thank you.

 

 

Awesome!  Glad you guys got it figured out!

[Guest]

10 hours ago, Igor_U said:

Morning,

So it turns out that good people at Progressive Air did send the restrictor fitting back to me before shipping engine to the Lycoming. We managed to installed it and connect the hose without removing the lower cowl (PITA on M20F with Ram air) so I flew my plane for 2h above Paine Field to break in the engine. It was busy in the pattern (great day for flying at PNW) but controllers were nice about it and pointed the other traffic so I could pay the attention to the engine monitor.

Engine ran great with CHTs in 75% cruse at about 350F and oils temp at 185F.

Attached is the race track from Flight aware.

 

Thank you.

 

 

Progressive Air in BC?

 

[carusoam]

Great follow-up Igor!

Thanks for sharing the details…

Best regards,

-a-

[Igor_U]

13 hours ago, M20Doc said:

Progressive Air in BC?

 

Yes.