Need better oil pump

searched and searched, to no avail

my stock 99 4.0, aw4 oil pressure drop out at idle after about 30 minute or in heavy traffic.

changed the sensor, made sure the little rubber o-ring wasn't cracked ect.

changed the pump to another oem ok for a while but same stuff after 90 days or so

motor has been pressure tested...ok there

where and what kind of aftermarket pump should i look for?

tia

cipey

What oil?
What filter?
How many miles?
Just what is the pressure now?
Stock or aftermarket guage ?
Normal hot idle oil pressure is around 10-13 psi,above 1200rpm 40+ psi.
The above is with recomended 10w-30 oil and a NON-Fram filter.
Wayne

Melling sells a high volume pump.

I'm at 15psi at idle hot and about 60psi running.

10w30 oil WITH a FRAM

well my 93 is about 30 psi at 700+- rpm and 50+ at 1500 rpm with 10w30 on a high flow pump from napa.

my 90 is the same with factory pump

both engines have about 120K miles

I do not use fram filters and have flushed the engenes every 4th oil change and my oil seems to stay clean till about 5000 miles or there abouts.

Try some heavier weight oil (10w40).

Stick with K&N gold oil filters and if you can, look into the HP3001. It allows for an additional .5 quart and provides better filtration.

If you really worry about oil starvation issues, get a remote oil filter kit and plumb it for an oil cooler (adds another quart or so). More oil = better. More filtration = better. Just my two.

well I know on the older models they are more prone to voltage (ground) issues, that create a false reading on the electrical gauge. Yours could be suffering from this when say the fan comes on or the heat raises the resistance in all the under hood wiring.

I went from 5-10PSI at a idle to 30ish with only adding a octopus of grounds under the hood from the battery. just something to concider, as it helps everything, not just the poss oil pressure reading.