I have a bad fuel pressure sending switch on my MCI 8 (8V-71). Was wondering what the switch's pressure should be so I can replace it. I looked in my manuals but could not find a listing for it or it's specs. Thanks in advance for the help.
David V. (Spartanburg SC)
David, I corrected your topic
Nick-
I think it is around 6-9 PSI, my 8v71 carries about 20 PSI of fuel pressure at idle. I had to replace my fuel pressure switch several years ago when the original started leaking diesel fuel. I found the PSI setting and went to a local parts house. They had a switch that matched the PSI rating but was physically smaller. I bought and installed it. Within about 3 months, I had trouble starting my bus. I traced it down to the fuel pressure switch. I then called Luke at US Coach and order a switch from him. It was larger in size (same as OEM) and has been used now for about 5 years. Moral of the story, make sure your replacement switch has contacts large enough to do the job. The switch from Luke was about $3-4 dollars more than the off the shelf replacement. Hope this helps, Jack
My 8V71 has two Normally Closed switches. The 7 PSI opens when the engine starts and prevents further use of the start button.
The 15 PSI opens above idle speed and prevents use of th air shifter when in neutral, if transmission is not in neutral this switch does nothing.
I recently searched for possible replacements and found :
Holley 15670 N/C adjustable but factory set to open at 7 PSI
Holley 15680 N/O adjustable but factory set to Close at 15 PSI
Holley 15690 N/C adjustable but factory set to open at 15 PSI
There are more in the series but these are all I made note of.
Dave