New to me a co-owner of a 1985 Cessna 182R. In addition to the annual, we had a JPI 830 installed. We were not able to fly her prior to purchase so don’t capture any readings of manifold pressure until post annual and 830 install.
Basically, the MP readings through both the original analog instrument as well as the 830 is reading high. At ambient pressure (engine off) they are reading properly. But once the engine is started up the numbers we would be expecting to see during run up are not there. At 1000 RPMs we’re getting about 19.5. At idle (1800 RPMs) we’re reading 18.5. At 1700 RPMs we are at 19.3.
The 830 sensor actually sits between the analog gauge and the line and were giving us the same reading. To troubleshoot, we then removed the 830 hardware/sensor tied into the back of the analog gauge and got the same numbers out of the analog gauge at those RPMs. When we were removing the 830 sensor we pulled a vacuum by hand on the analog gauge which held just fine. So both gauges are reading the same with the sensor installed or removed. The engine feels great and she is flying well so we don’t think there is an issue there.
What we are hoping for help with would be:
1. What MP readings would we expect to be seeing at sea level at those RPMs if it was operating properly?
2. If the engine is operating well and everything else seems fine, any thoughts on where we should start hunting? My assumption is a slight leak at the fitting or some other hopefully common leak?
Thanks all, have already spent some coin and hoping this is an easy(ish) and inexpensive(ish) fix. But dont want to do much outside the pattern until we can get accurate readings. Many Mahalos!
Basically, the MP readings through both the original analog instrument as well as the 830 is reading high. At ambient pressure (engine off) they are reading properly. But once the engine is started up the numbers we would be expecting to see during run up are not there. At 1000 RPMs we’re getting about 19.5. At idle (1800 RPMs) we’re reading 18.5. At 1700 RPMs we are at 19.3.
The 830 sensor actually sits between the analog gauge and the line and were giving us the same reading. To troubleshoot, we then removed the 830 hardware/sensor tied into the back of the analog gauge and got the same numbers out of the analog gauge at those RPMs. When we were removing the 830 sensor we pulled a vacuum by hand on the analog gauge which held just fine. So both gauges are reading the same with the sensor installed or removed. The engine feels great and she is flying well so we don’t think there is an issue there.
What we are hoping for help with would be:
1. What MP readings would we expect to be seeing at sea level at those RPMs if it was operating properly?
2. If the engine is operating well and everything else seems fine, any thoughts on where we should start hunting? My assumption is a slight leak at the fitting or some other hopefully common leak?
Thanks all, have already spent some coin and hoping this is an easy(ish) and inexpensive(ish) fix. But dont want to do much outside the pattern until we can get accurate readings. Many Mahalos!
