There has been some discussion that turning up the housing pressure in the DS4 will result in crisper injection pressure events - it presently runs from 25psi at low rpm to over 125psi at hi rpm.
Excess fuel is returned to the tank.
One thing that must be remembered when considering upgrading the lift pump - Diesel fuel foams, easily - warm Diesel fuel foams very easily.
More warm fuel returned to the tank will further aerate the fuel, causing even more problems at low fuel levels in warm weather - DTC35\equiv, injection pulse width too short - usually results from bubbles in the fuel.
Higher pressure pumps are also usualy higher volume pumps - the replacement solenoid-type flow-thru pumps like the oem version on your truck are produced in several ranges up to 14psi and 35gph, and those are designed to shut off when they reach spec'ed pressure.
They are direct replacement, and IIRC, Bill and JK both offer a version for high performance - and, they are flow-thru if they die, which won't leave you totally stranded.
The ideal would be to maintain ~5psi at full throttle when 'hot-chipped' or 'hot-flashed' - we're doing some experimenting with inlet\outlet diameters in the fuel cannister and DS4 inlet, with the upgraded solenoid pumps, to enable more volume at the lower pressures, while maintaining the pressures.
Upgrading the EFI 6.5 Diesel fuel supply system is not quite as easy as with a gasser
Increasing supply pressure on the DB2 must also be managed, as increased housing pressure severely effects the advance system
Last edited by gmctd; 03-13-2007 at 00:07.
jd
'96 Dodge 3500HD cc 2wd drw............'89 GMC 3500 cc 4wd drw
5.9 12v #10TST 6sp SBC13-1.375.......6.5TD EFI maxEtorq v2.0 DSG
DODGE makes it CUMMINS shakes it.....4L80E 205 4.10 Dana60\70HD
6 in a row makes it go.......................Grandpa's big truck
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