Continental IO550 Ovation JPI peaks too early

[redraider]

Hello All:

 

2004 Ovation with JPI.  When leaning lately, the #3 and always the #3 cylinder peaks first and early making it difficult to get a true peak reading and thus a true ROP/LOP setting. (Not getting into that discussion, here.)   It happens more often than not.  I try and lean very slowly, but most of the time lately, #3 peaks very quickly.  I simply want to know if anybody else has experienced this and what may be the cause(s).  I suspect dirty injector on #3 or weak or failing probe on #3.

Any thoughts?

redraider

[ilovecornfields]

I would start with downloading the JPI data and sending it to Savvy. They have a free service in addition to the paid one, but either one seems to give you a wealth of information. Nice to see the trends too and see when the problem started and if it’s getting worse, only present at high power settings, etc.

[kortopates]

Slim chance its a probe issue from what you describe. But as mentioned above you need to look at the downloaded data and the best data to resolve this is a series of slow gami spreads. Can't get good data with a big pull or even the typical 6 sec data sampling. Be sure to also make sure your engine monitor is sampling at 1-2 sec data rate to ensure the best data resolution. Assuming your #3 is a lean outlier as you expect, the first step is always to clean that injector to see if dirt is making it lean. Then repeat the gami spreads and check to see if that cleared it up. Everybody (fuel injected) experiences a dirty or partially clogged injector eventually; pretty common especially after maintenance.

[kmyfm20s]

Check the intake gasket and make sure the nuts are tight on the collar holding the pipe into place. I have had those get a little loose before creating an air leak.

[Cruiser]

The IO-550 is very well balance from the factory. You should be able to get at least .5 gallon spread or better. You definitely have something wrong, an air leak or clogged/bad injector.

[kortopates]

21 hours ago, Cruiser said:

The IO-550 is very well balance from the factory. You should be able to get at least .5 gallon spread or better. You definitely have something wrong, an air leak or clogged/bad injector.

You're lucky, perhaps yours has the TCM position tuned injectors installs. The majority need some form of tuned injectors to get within 0.5. 

[StevenL757]

On 8/20/2018 at 11:30 AM, redraider said:

Hello All:

2004 Ovation with JPI.  When leaning lately, the #3 and always the #3 cylinder peaks first and early making it difficult to get a true peak reading and thus a true ROP/LOP setting. (Not getting into that discussion, here.)   It happens more often than not.  I try and lean very slowly, but most of the time lately, #3 peaks very quickly.  I simply want to know if anybody else has experienced this and what may be the cause(s).  I suspect dirty injector on #3 or weak or failing probe on #3.

Any thoughts?

redraider

A few questions...

- What power settings are you choosing when this happens?  Is the engine upgraded to 310HP or 280?

- At what altitude(s) does this occur?

- As others have suggested, when was the last time your induction air gaskets were torqued and your injectors cleaned?

- What model JPI do you have?

Steve