Posts: 350
Threads: 28
Joined: Aug 2017
I am guardedly optimistic that I have turned the corner on the generator, having replaced the lift pump and sealing washers , etc .
But now...
In keeping with 2020 , I have a fuel delivery problem to the Detroit 8v92TA , Silver mechanical .
New fuel /water separator, Parker 1000 clone .
New primary and secondary spin on filters , Luberfiner. Old filters Fleet Guard . Primary somewhat "blacked", secondary looked pretty bad .
Fuel /water separator replaced first , engine started prior . Old ConMet units had sludge in bowls , I'm told algae .
I should note that the coach has not been driven in almost a year, started and warmed up at intervals , about five weeks being longest while compressor and alternator jobs were going on.
Noticed unstable idle after separator change , might have been present before , but I was hypersensitive after changing separator. Engine wasn't " hunting " , would just drop to about 350 rpm from the normal 550 / 600. I could ease the throttle on slightly, up to 1k rpm , then back off and idle would settle to 500 for a minute or so.
Changed primary filter, new one filled with fuel .
Started , ran 10 minutes. Idle as before .
Next day , started , warmed up 15 minutes, shut down, changed secondary filter , new filled .
Restarted immediately, idle issue unchanged .
After a few minutes engine not sounding strong at all , throttled up , would Rev to about 1500 , then faltered and would only turn 1k , max .
Next day , engine wouldn't start .
Fuel present in separator bowl .
Per Detroit manual , using electric pump plumbed into secondary filter mount , pumped about a quart of fuel into system .
Engine started right up , strong idle . After short time engine faltered , I switched off .
Next : plumbed electric pump to engine fuel pump inlet hose ( after priming ) , inlet for electric pump into 2 1/2 gallons of clean fuel .
Engine fired up, sounded great .
Fuel level in 2 1/2 gallon container dropped rapidly (fuel returning to main tank ) , I chased it with more fuel . Once warmed to 130 degrees or so I fed throttle in lightly, revs went to 2100 quickly ( don't like revving with no load, got away from me ) .
Maintained 1500 rpm with light throttle .
Reconnected plumbing as normal , primed , same issues after a few minutes.
Disconnected both ends of hose from separator to primary filter , blew through it , sprayed fuel in compartment.
BTW , on this one at least , the hoses in and out of the separator cross before heading to front /rear , hose at rear of separator heads forward to tank .
Yesterday, pressurized fuel tank via vent , no joy .
Fuel level in tank is about 8 1/2 inches , wondering if this too low for the vacuum of the pump to lift .
Presume there is a check valve somewhere that could be sticking .
Very wordy and much to unpack , I know , any input appreciated. I have a chance to make the finals if I can get this going , otherwise it will be a wash for this year , try for Spring race '21 .
Thanks , Chris.
1986 #89
VIN 007
Detroit 8V92 TA 475 HP
Allison four speed
Chris and Sharon Hand