Plane dies during taxi without the boost pump on.

I have a 2002 SR22. During the taxi process if we turn off the boost pump like it states to do on the checklist the engine dies. 2 CFI’s with lots of Cirrus time have told me they have seen this before, and to just leave the boost pump on after landing to prevent the engine from dying. Have you heard of this, or experienced this?

Another CFI with a good amount of Cirrus time said this isn’t right and we will eventually burn out our boost pump. Any comments or suggestions ? Thanks

We are landing in the pattern with full mixture. Some replies I have already received said my mixture is too lean. Once we pull off the runway we typically pull the mixture back to the “t” in mixture.

Thanks guys.

Your idle mixture is probably too lean. Check idle rise, and have it adjusted as necessary.

Those 2 CFIs… Well…

The other one… Somewhat better…

The mechanical fuel pump, throttle body and flow divider are indicating a desire for pressure check per the latest SID from CMI to start… Then afterwards a flight and landing check… Next step would be a start up after allowing for a FULL cool down to room temperature.

You may be surprised how the response changes… And what is indicating a need for maintenance.

Are you landing with the engine running LOP? Or do you go full rich (in the pattern)?

Typically I leave the fuel pump on until exiting to the taxi way. When I turn it off, I gently push the throttle forward slightly. This is enough to keep the engine running. I land with the engine running LOP, which works better for this engine.

If you go full rich mixture when landing, you might need to pull the mixture back when taxiing. You will see the rpms increase. Add a touch more throttle.

I’ve gone years now since having the engine die after landing.

Idle mixture too lean. It should run at 740 rpm with a 50 rpm rise with no boost pump. The mechanic will know what the latter means

Steve, You got some great advice on your problem. Worth $65. Why don’t you join COPA so you can have even more knowledge on your airplane and flying.

Just the Jeppesen discount for COPA members is worth the dues.


Let me second John Y’s invitation to join. We would love to have you as a member.

As for taxiing with the boost pump, as a long time owner (of SR22 turbos), I always leave my boost pump on now. (I view this largely as an owner preference.) In a couple of thousand hours I have never burned out a boost pump, but I have had the plane die on me a few times while taxiing (and flying) with the boost pump off.

Trying to restart on a busy taxiway at a busy airport is no fun. Neither is restarting in the air.


. . . or while still on the runway just shy of the hold short line.

I’m pretty sure I’ve read somewhere a warning about the effect of lead bromide deposits on exhaust valve stems and valve guides caused by idling with the boost pump on and mixture too rich.

PS: I used to have the same issue. Mr Barker set up my fuel pressures after replacing my leaking mechanical fuel pump. Since then, it idles just fine with the electric boost pump off.


Haven’t heard about lead bromide deposits, or whether that’s even a problem; but I’m sure if I had frequent access to Jim B, I would have a lot fewer mechanical issues. smile

Unfortunately, I’m based on a field where just getting an oil change can be an adventure.

Warmest regard,


Mark Waddell:
I’m pretty sure I’ve read somewhere a warning about the effect of lead bromide deposits on exhaust valve stems and valve guides caused by idling with the boost pump on and mixture too rich.

Do you lean on the ground?

via COPAme
Asus Nexus 7

Hi Clyde,

Yes. After clearing the runway, I follow the After Landing Checklist and FOM After Landing guidance:

  1. Power Lever - 1000 RPM

  2. Fuel Pump - OFF*

  3. Mixture - LEAN for maximum RPM rise**.


  • OFF per the FOM and the SR22NA POH. The TN Supplement’s After Landing checklist says ON or LOW BOOST.

** Check for ~ 50 RPM rise. The rpm rise is diagnostic … just one more way the engine talks to us. Checking whether you can idle with the boost pump off, the same.


There are several threads over on the member’s side that discuss lead bromide deposits and why we should aggressively lean during all low power ops, which I’m sure you’ve read as well. Several discuss the boost pump and idle mixture issue. There’s all you ever wanted to know about the sniffle valve…and more.

Since I can’t remember the exact thread I had in mind in my post above, I’ll go back to lurk mode on this thread. :slight_smile: