Hello all. I just bought a 97 van with a 7.3 in it. The van was converted to run off vegetable oil several years ago and runs well on diesel and oil. It does have a lift pump that is going to need replacing (it pulls in air whenever the engine is under higher loads/high acceleration).

My concern is with low oil pressure read-outs on the stock guage. It reads just barely into the "normal" range at higher rpm (can't say how high as there is no tachometer) and then, at idle, will drop to zero or near zero. Runs fine through all this, good power.

Finally, the guy I bought it from said it does not like to start in cool temps (whether it has been running on diesel or vegetable oil.) He has to plug in the block heater during winter in western oregon. I have a pickup with a 97 PSD (same engine), live in the same area, and definitely do not have to assist with the block heater.

Based on info i picked up in other forums i plan to check the oil pressure with a mechanical guage at the port near the oil filter. Any ideas?

Thanks

 

Possibly a bad Glow Plug Relay. You can test it with a multi-meter. Could be bad Glow Plugs too. You can ohm those out with the same Multi-meter.