I have a 1992 1 ton 6.5 diesel. It always starts fine but when the engine gets up to temp ,the oil pressure drops. so I shut it off. Then it won't start again till the engine is completely cool. HELP!!
It's normal for oil pressure to drop when hot, as long as it' not too much? 2 things I would check first. Make sure you have 2 good batteries and excellent cable connections (especially at the double + terminal on the right battery). My 92 did the same thing, and even though it seemed to crank well, when hot it wouldn't start. It had 1 week battery, and now it starts every time. Another thing is that the 92 does not turn on glow plugs when engine is warm. Don't need glow plugs with warm engine, but if engine is week, or not cranking fast enough, you can try heating the glow plugs first by applying a jumper wire across both of the red wires on the glowplug relay for 10 or 15 seconds before starting. That worked for me to start the hot engine when my battery was week.
Your 6.5 DB2-4911 Inj Pump was designed for higher injection pressures, but the head-rotor clearances were same as the 6.2 DB2's.
Time and wear and excess clearances resulted in the hot no-start symptom, so Stanadyne released a new head-rotor assembly, with ceramic rollers and other improvements, available to field shops for upgrade.
If your IP is a black-label, it will require rebuild to the current standard - a 1992 DB2 is way, way passed tired.
If your IP is black-label with a green-tag on one of the top-cover screws, it has the upgrades, but may be tired.
If your IP is a blue-label, with or without the green-tag, it has the upgrades, but may be tired.
Either of the last two, you may need electrical system service - batteries, cables, starter-motor, etc, to get the cranking speed up - or the pump may just be tired, and requires rebuild.
The model # label is on the rear, facing the intake manifold
Low oil pressure, replace the OPS, behind the driver's-side head\intake manifold area.
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