Have found a replacement for the PB sensors (qty 2) on my '85 LTD - from the CX500-CX650 forum. The fellows over on that site have done a lot of research/testing and have found that the Suzuki sensor - Brand: Denso. Type number: 100798-5630. Suzuki ordering number: 15620-35F00. Suzuki description: Sensor Boost, IAP (Inlet Air Pressure) sensor, is an almost direct replacement for the Honda OEM PB sensors on their 500/650 Turbos.
One of the issues that was found is that the internal construction/connections was less than stellar (they took one apart) and since the connections were not soldered, the internal connections would come apart such that vibration would cause the PB sensor to fail. This is a good hit/miss scenario when troubleshooting.
Did some investigation into the difference between the Suzuki sensor and the OEM PB sensor(s) on my '85 LTD. I took some measurements today. It was mentioned that static testing may not be indicative of dynamic testing; however, it is a starting point.
The power source for this was 3 - AA batteries in series giving me 4.8 VDC. I hooked up a test circuit with multimeter. Here are my readings, read in 3 columns - inches of Hg/Suzuki sensor - VDC/Honda OEM PB sensor - VDC:
0 inch of Hg/3.45/3.63
5 inch of Hg/3.1/3.14
10 inch of Hg/2.65/2.59
15 inch of Hg/2.18/2.0
20 inch of Hg/1.73/1.43
25 inch of Hg/1.26/0.88
I have checked the vacuum at the PB sensors and at approximately 3000 RPM the vacuum to the sensors is 10 to 12 inches of HG and remains steady at these vacuum values as RPM increases past 3000 RPM. At 12" of Hg - Suzuki sensor - 2.46 VDC.
I have installed the Suzuki sensor(s) and did a road test. Seem to work well, bike idle is steady and it pulls nicely up through the RPM. Will keep installed for a few weeks and check fuel economy with these installed. Also cooling down coming into fall, so will be interested how the bike starts and idles in the cooler weather.
Here are a few pics of the testing and Suzuki sensors ready for install.
Still have some testing to do. Would like to test the sensor(s) when engine is started. Would only have to add one wire to the harness.
More to follow.
Cheers
One of the issues that was found is that the internal construction/connections was less than stellar (they took one apart) and since the connections were not soldered, the internal connections would come apart such that vibration would cause the PB sensor to fail. This is a good hit/miss scenario when troubleshooting.
Did some investigation into the difference between the Suzuki sensor and the OEM PB sensor(s) on my '85 LTD. I took some measurements today. It was mentioned that static testing may not be indicative of dynamic testing; however, it is a starting point.
The power source for this was 3 - AA batteries in series giving me 4.8 VDC. I hooked up a test circuit with multimeter. Here are my readings, read in 3 columns - inches of Hg/Suzuki sensor - VDC/Honda OEM PB sensor - VDC:
0 inch of Hg/3.45/3.63
5 inch of Hg/3.1/3.14
10 inch of Hg/2.65/2.59
15 inch of Hg/2.18/2.0
20 inch of Hg/1.73/1.43
25 inch of Hg/1.26/0.88
I have checked the vacuum at the PB sensors and at approximately 3000 RPM the vacuum to the sensors is 10 to 12 inches of HG and remains steady at these vacuum values as RPM increases past 3000 RPM. At 12" of Hg - Suzuki sensor - 2.46 VDC.
I have installed the Suzuki sensor(s) and did a road test. Seem to work well, bike idle is steady and it pulls nicely up through the RPM. Will keep installed for a few weeks and check fuel economy with these installed. Also cooling down coming into fall, so will be interested how the bike starts and idles in the cooler weather.
Here are a few pics of the testing and Suzuki sensors ready for install.
Still have some testing to do. Would like to test the sensor(s) when engine is started. Would only have to add one wire to the harness.
More to follow.
Cheers