flanza

Hello all I'm not sure this is where to start this but here goes.
My 1991 4runner 3vze oil pressure gauge is not working. Its all the way over to the left under L is doesn't even flicker when you turn the ignition on.
So in order to check the gauge I took the lead off the sender and grounded it to the engine and the gauge slowly starts to make its way all the way across to H until I disconnect it then it goes back to low. So I would assume the gauge and the wiring to the gauge is working correctly.
So then I replaced the sending unit thinking it must be faulty. Still nothing with the new unit. Humm maybe no oil or no oil pump? Checked the oil, full, and hooked up a mechanical pressure gauge, pressure about 20-30 PSI Lower when warmed up and idle. So good to go there. Lastly I tried, maybe it's a ground issue so hooked up a makeshift ground wire from the unit to the block because when this unit is screwed in it's suppose to be grounded right? Nothing
Starting to wonder if it just doesn't like aftermarket sending units and needs the factory one $$.


any thoughts out there would be helpful. ??? M mystery to me ?

scope103

There's a test procedure in the FSM. I would start there.

http://personal.utulsa.edu/~nathan-b.../6combinat.pdf

flanza

Cool THX

wyoming9

iTrader: (1)

Possible in this day and age you got a sending unit boxed wrong or just failed out of the box.

Did you get the one for the light by mistake ??

it is not sending a signal to the gauge that the gauge is looking to see.

scope103

It is also possible you damaged the gauge. The gauge sender never completely shorts to ground, but the idiot light sender does. I am told (on this site) that accidentally using an idiot light sender on a gauge shorts the gauge to ground and damages the gauge. Similarly, grounding the lead to the engine.

flanza

No Wyoming9, the part # says its for the Gauge wwhich is what I need.
Just did all the test that were in the link that scope 103 sent me it passed all but the one about putting a LED test light to it from the positive side of the Bat. to the sender lead It's suppose to be off when switch is off and blinking when running. Mine was solid light no blink. So then it says "If not as specified replace sending unit" Or something like that, which I did with a factory sender from the dealership. Beats Me ??
Wonder if the dealer can diagnose it w/o rapping me $$ wise.

clok

iTrader: (2)

My oil pressure gauge was always pinned at H with the engine on or off so I replaced the sending and still the same results so figured it was the gauge so I just installed an auto meter gauge looks and works great.

flanza

Would that Auto Meter fit inside the Factory Instrument Cluster? And Is it Mechanical. ?
Not really Crazy about Hot oil inside the cab.

clok

iTrader: (2)

Yes its mechanical but I used a steel braided line and no won't fit in cluster i bought a 2 gauge a puller pod mount also have a air fuel ratio gauge but not worried about oil in thecab its pretty secured.

flanza

Hmm. ? braided now there's a thought. The only ones I ever see are those cheap Plastic tubes.


Thanks for the Idea.

flanza

Well I finally got it fixed. Just FYI if anyone's interested.


Long story short. I found a 95 instrument cluster in the junk yard replaced the whole cluster and now it's working. !!!


On to other exciting projects. Ah the list is long.