-
While I was warming my car up to set the timing last night, I checked the fuel pressure readings.
I have a B&M filter top mechanical gauge and an electronic Intellitronix gauge inside with the sender spliced into the fuel hose from the filter to the fuel rail.
The only place these gauges agree is at idle.!
Here's the data I saw:
After engine off for 10 minutes:
B&M = 42psi, Int. = 47psi
Immediately after engine shutoff:
B&M = 49psi, Int. = 56psi
At Idle with vacuum connected:
B&M = 57psi, Int. = 57psi
At Idle with vacuum disconnected:
B&M = 79psi, Int. = 71psi
Wonderful, eh?
I'll be replacing the B&M gauge with another gauge. The new one goes to 160psi and, even though it's not a great rating (+/- 2%), has a rated accuracy that can be considered.
If the new one disagrees with the electronic one too, I'll put the a mechanical gauge where the electronic sender is and see if the mechanical gauges disagree.
------------------
Greg Holden
96 GSR, JSRC, I/H/E, yada yada yada...
My JRSC Install Site
-
To date I've had my autometer electrical short sweep fuel guage and B&M guage for about 4 months now and they always agree within +/- 0.5psi. Pressure readings at idle and 0 vacuum always agree, as well as boost.
-
I would tend to trust the B&M more if it weren't for the fact the 57psi to 79psi is such a huge jump for going from 22" to 0" vacuum.
We'll see what the next gauge says.
Greg
-
My b&m gauge went bad. I had the 10psi difference between gauges now i have an autometer under the hood and in the car and they read the same. I say it is the B&M gauge.
