92 6.5litre TD pickup pump

[92GMfan]

I have a 92 2500 chev pickup with a 6.5 litre turbo diesel. I replaced the electric pickup pump with a new one due to a restarting issue when it was hot. The problem is that I am not getting any power to the pump on startup. I can force it to run manually but won't run on its own. I checked fuse, it was good. I suspected the fuel pump relay and replaced it but still no power to pump. It's just not getting anything from the relay. Batteries are not good, could this be a problem with the relay? Engine will turn over for a while but then they are dead..

My understanding is: power from relay to start pump and then it gets power from oil pressure switch.

Stumped

[DmaxMaverick]

Welcome aboard!

Sounds like the OPS (Oil Pressure Switch). Not an uncommon issue. The best solution is to replace the switch, and install a relay to carry the power to the pump (the current "relay" is only for pre-start). Kennedy offers a lift pump controller, which has many advantages, but is pricy. Use ONLY the OEM replacement OPS. Aftermarkets are more trouble than they're worth.

[92GMfan]

I'll give that a try tomm. Thanks for the info.
Keep you posted.

[racer55]

If you have trouble starting the truck when hot,the problem is more likely due to a worn injection pump.

Get the lift pump repaired first and then when it still starts poorly hot-pour water over the injection pump abnd try starting again-improvement indicates IP replacement time.

[92GMfan]

Thanks for all the help. It turns out that it was the oil pressure switch. It's been replaced and back on the road again.
It's great to have access to resources like this. A great forum.

[racer55]

google "OPS relay mod" and install it for long term reliability.