More 8V71 Woes - Page 2
 

More 8V71 Woes

Started by BlueScarecrow, November 15, 2015, 09:29:06 AM

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daddyoften

Electric pumps are better pushers than suckers. They may work ok way down by the filters but would perform much better nearer the tank
FWIW
Eric


Sent from my XT1254 using Tapatalk
68' PD 4107
Central WY

blue_goose

My coach has an electric fuel pump at the tank installed by MCI.  They are not made to pull fuel.
Jack

luvrbus

Buy a Airtex flow through inline electric pump rated for diesel,you are only priming not running the engine from it.You can mount it at the filters or anywhere in line without any ill affects on your fuel system and it works 

good luck
Life is short drink the good wine first

ol713

Quote from: BlueScarecrow on November 16, 2015, 02:53:22 PM
I would like to put an electric fuel pump by the tank. Any make or model I should look for?. The fuel pressure switch has a broken wire. The ground is ok. I thought that switch disabled the starter after the engine is running. Does it also affect the fuel delivery?

Thanks!!!!!

           YES  ---   I believe so.    Maybe someone else can verify this.
                                            Merle

luvrbus

Yep the fuel switch is there to just disable the starter,there is a switch to over ride the fuel switch if needed in a emergency and his starter is engaging so it's not the fuel switch   
Life is short drink the good wine first

bevans6

The fuel pressure switch has absolutely no effect on fuel delivery.  It is a normally closed switch that opens when it senses around 15 psi of fuel pressure.  It's actually a good way to tell if you have prime, if you felt like hooking a test light to it or something.  What it does is provide the ground connection for the starter solenoid.  If there is no fuel pressure the starter solenoid has a ground connection and the starter can turn on.  If there is fuel pressure, the ground connection is open and the starter cannot operate.  Top Tip - if you have an Airtex fuel pump to prime with (like I do, thanks again Clifford if I didn't already credit you with giving me the idea) the Airtex pump can generate enough fuel pressure to trip that switch open and you get a no-start.  Happened to me, took about 3 minutes for me to disable and bypass that switch after spending some indeterminate amount of time figuring it out...   Oh the lost hours spent searching for the latterly obvious....   ;)

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

robertglines1

on the 78 mci 8 v 71 had the transfer pump go out. Mounted on front of engine( opening rear doors is rite there). pull line going to injectors/head and see if fuel is coming out of it. when cranking.  FWIW   would pick up out of a 5 gal can on ground but wouldn't draw from tank. Was weak.   changed it and all was good.
Bob@Judy  98 XLE prevost with 3 slides --Home done---last one! SW INdiana