Engine cuts out on hard acceleration

[Ceflaw]

HELP !!!!!!!

 

 

96 Mooney TLS Bravo 

Just overhauled with 20hrs

Took delivery near Chicago run up ran fine straight up to 11,500 where I flew straight to KFRG on Long Island 

 

Coming in for landing push throttle in a little aggressive engine cuts out then springs to life. 

 

So far we have troubleshot:

The upper deck;

Fuel “spider”

Fuel lines and pumps

Timed and adjusted mags

Sent the rebuilt Servo back to Precision 

No change

Then asked

Precision send us new Servo

No change 

 

IDEAS

 

Charles Finelli

212-869-2224

N75PH

Pop

[Boilermonkey]

Was the turbo overhauled?  Wondering if the wastegate might be sticking causing monetary rich or lean conditions.   Do you have engine monitor data?

[Fly Boomer]

2 hours ago, Ceflaw said:

Coming in for landing push throttle in a little aggressive engine cuts out then springs to life. 

Someone much smarter than me will have to help you.  I just wanted to welcome you to MooneySpace.

[Ceflaw]

Thank you 

[LANCECASPER]

17 hours ago, Ceflaw said:

HELP !!!!!!!

 

 

96 Mooney TLS Bravo 

Just overhauled with 20hrs

Took delivery near Chicago run up ran fine straight up to 11,500 where I flew straight to KFRG on Long Island 

 

Coming in for landing push throttle in a little aggressive engine cuts out then springs to life. 

 

So far we have troubleshot:

The upper deck;

Fuel “spider”

Fuel lines and pumps

Timed and adjusted mags

Sent the rebuilt Servo back to Precision 

No change

Then asked

Precision send us new Servo

No change 

 

IDEAS

 

Charles Finelli

212-869-2224

N75PH

Pop

@philiplane works on a lot of Bravos

[philiplane]

This is a fuel issue. It's either one or both of these:

The servo is not sensing the power request and sending more fuel (leaks in upper deck reference line, incorrectly set mixture control, faulty servo diaphragm)

There isn't enough fuel available to send (low pressure, low flow, or blocked fuel tank vents).

[Ceflaw]

The Servo was rebuilt with the engine, it was removed and sent back to precision reinstalled same issue 

Precision then built a new one and we swapped and same issue. Confident it is NOT the Servo. 
 

checked fuel pressure with a handheld after electric and b4 engine after engine b4 Servo after Servo b4 spider and out of spider ALL GOOD with engine running and with different mixture settings and mags switched this is all done with air filter removed 

they checked for intake leaks. Checked upper deck all the way to the sleeves on the injectors, matter of fact we removed the upper from the injectors which at idle at sea level really do nothing. 
 

is there an airline on that engine that if it was placed backwards upon installation i.e. line that is SUCKING is placed in spot where it should be blowing on the Servo or mags or manifold that could cause this. 

[Ceflaw]

Have JPI, flight back and indications on EGT were dead even cylinder temps all good

 

[Ceflaw]

Have JPI, flight back and indications on EGT were dead even cylinder temps all good

 

[Ceflaw]

New turbo and wastegate controller 

once again wondering if a line from turbo to mags or something is backwards 

I wouldn’t think it could be an oil line since that would blow up engine rather quickly 

we also took off p leads to mags 

what exactly happens is:

idle quick throttle application the engine seems like you shut off the mags for 2 seconds then bursts alive 

at 2000 rpm same thing with a backfire

 

[Rick Junkin]

@philiplane Could the backfire at 2000 RPM be caused by a fuel delivery issue or might it point to a possible ignition drop-out? Asking for my own education.

Cheers,
Rick

[Ceflaw]

Promise when I found out it will be posted 

[Boilermonkey]

If you can increase the JPI sampling frequency and replicate on the ground you might get some better data.  Maybe get Savvy involved.

I agree this is a fuel or air problem.   

How "quickly" are you advancing the throttle when this happens?    If you go slowly is it ok?   

If it happens only when you move the throttle quickly my mind starts thinking about something stuck or leaking, not something installed backwards.  Maybe lube the waste gate.

I really understand your frustration.   A week after getting our Bravo back from a firewall forward reman I had the throttle become disconnected on base leading to an engine out landing.  Later that day I almost had a catastrophic failure, the spinner was incorrectly installed leading to a massive bulkhead fracture.  It took another 6-8 weeks after getting the plane back to finally get it right.  Missed OSH.  And broke my confidence in the airplane for a few months.   100 hours later it's all a memory and she's flying great.

 

[Ceflaw]

Only happens on quick throttle advance like when you are coming in for landing on windy day and you need throttle to arrest some wind sheer 

otherwise you would never know. 
 

the waste gate is involved at low power and RPM ??????

[Boilermonkey]

My guess, and I'm not an A&P, is that at low power the turbo is spun down and wastegate set at a specific angle.  As the turbo kicks in something is not spinning up or opening to allow proper air into the engine and thus flooding or providing to rich of a mixture.

[Ceflaw]

Interesting 

i will forward that to AP

[tls pilot]

My suggestion

call Lycoming

it could be the Density Controller as that modulates the Wastegate movement

the Bravo has a Differential and Density controller

i have seen issues w Density Controllers doing what you describe

again call Lycoming 800# and speak w one of the techs

 

Getting the controllers tested 

is not difficult at the correct place

 

[Ceflaw]

Has anyone heard of air bubbles being sucked in through the fuel selector causing an issue with fuel Servo metering 

[N201MKTurbo]

17 minutes ago, Ceflaw said:

Has anyone heard of air bubbles being sucked in through the fuel selector causing an issue with fuel Servo metering 

Yes, mine has done it. Not so much on rapid throttle change, but on high power settings. switching tanks always made it different.

[Ceflaw]

All indications now favor a very rich running engine evidenced by black smoke when rapid throttle. 
Precision Airmotive believes all 6 restrictors in the injection nozzles are missing 

then reminded him they are Gami not his, he is not familiar with gami but thinks it may be true for them. 
 

Thoughts???

[LANCECASPER]

54 minutes ago, Ceflaw said:

Precision Airmotive believes all 6 restrictors in the injection nozzles are missing 

then reminded him they are Gami not his, he is not familiar with gami but thinks it may be true for them. 

That's easy enough to figure out. Pull an injector and see if it's there.

[Ceflaw]

Found problem 

a mud bug plugged the line from intercooler to upper deck