I think its time to raise the yellow caution flag here before someone’s airplane burns to a cinder.
Continental engines are normally VERY easy to start cold. In fact, I had one with a bad starter on a ferry trip in Africa where it had to be hand propped for three straight mornings. This was a three blade prop in a Cessna 206 and it fired up each time in one blade. As to who would prop an IO-520 with three blades out there, it wasn’t me!!
It is time to come out and just say that something is wrong in the starting process of this engine and it ought to be addressed up front by Cirrus/Continental.
I base this observation on several facts:
The problem Rob Leach and I had starting N142CD in Ogden, UT. We created a huge lake of fuel under the cowling and were told by the factory to “prime some more” as we ran the battery flat. This was a definite fire hazard. We even tried a flooded start procedure with the same result - no cylinders fired. There just did not appear to be any fuel in the cylinders despite the flood on the ramp.
After the engine change, this same plane has had the same problem in Australia per Clyde’s recent post.
Walt has had the same problem in California.
Han has experienced it in Europe.
There is no way that you should have to run down a battery or create a fuel puddle below an airplane engine to start it. Something is wrong.
This engine has a top induction system unlike most of the other larger TCM engines. Whether that is responsible for its strange start characteristics, I don’t know. What appears to be happening is that when priming occurs, fuel is flowing but evidently not to an effective place for starting. Additionally, Walt reports something very strange – when he primes, the fuel flow reaches a peak and then goes to zero – this with the pump on, the mixture rich and the throttle full forward. I have never seen this occur in a Continental engine. With the controls in this position, fuel flow should be continuous. Evidently something is shutting off fuel flow to the cylinders but allowing it to flow elsewhere in the engine in order to reach the overflow drain.
Since I have neither a Cirrus at hand nor a maintenance manual, there is not much I can do to investigate this matter further. However, absent any insight from the manufacturer (and there ought to be some very soon, I hope), I would suggest the following procedure as an experiment:
For your next cold start, begin cranking the engine at the same time that you see the first indication of fuel flow from the primer. By doing this you will be sucking the prime vapor into the cylinders immediately, giving the engine a chance to fire while fuel is definitely there. It seems that by using the factory method, fuel vapor is draining away before combustion can occur. In short, it is like trying to start the engine on air alone!
I would appreciate any feedback on how this works for you. The current situation is abnormal and unacceptable. Unless it improves, someone’s airplane is going to be toast.