help with oil pressure gauge and sending unit

[Source3]

When I swapped the 1F for the 2F my oil pressure gauge read around the first graduation (28.4 psi according to the FSM) under load. This was low as my 1F (although only running on 4 cyl) read around the third graduation (58.8 psi according to the FSM) under load. Then one day I lost oil pressure. I could see the needle climb from way down low and barely touch the 0 graduation. When I ground the oil pressure sender wire, the gauge pegs out (max).

I installed a mechanical oil sender and the meter reads 43 psi cold and 38 psi warmed up at idle. 46 psi at 2000 rpm. Oil pressure good, bad sender?

So I replaced the oil sender unit with a factory one from CDAN. Recrimped the connection on the sender wire as the original wire was shot. I also check the oil gauge for issues. While I was removing the gauge I heard the backing fiber board snap. I glued the backing back together. The breakage should be a non-issue as the backing board looks non-conductive. With the new factory oil sender unit installed I still do not have oil pressure readings on the gauge.

I checked resistance on the gauge and I have good conductivity. I am using my stock cluster which is from a 73'.

The only thing I have not done was to replace the wire from the gauge to the sender unit. However, I believe the wire should be good as my conductivity is good (near zero resistance).

I wonder if a 73' gauge is compatible with a 2F? I would think so. I was also took resistance reading using a volt meter connected to the sender unit. Once warmed up and at idle (650 rpm), ohms = 41. At 2000 rpm ohms = 44. Ok, sender is working. Issue is with the gauge.

Any other suggestions what may be happening.

Thanks.

 

[Pighead]

Where did you install the new oilpressure sender? Same place as the 1F? (that won't work)
I would suggest a nice aftermarket mechanical oilpressure gauge with real numbers on the face.

 

[Source3]

Where did you install the new oilpressure sender? Same place as the 1F? (that won't work)

I replaced the oil pressure sender which came on the 2F in the same location, on the oil cooler. I did have to extend the wire so that it would reach to the passenger side. I checked my connections of the extended wire and it look fine. And CDAN ordered the correct oil sender unit which mounts of the oil cooler.

I would suggest a nice aftermarket mechanical oilpressure gauge with real numbers on the face.

I like the look of the stock gauges and not extra gauges mounted here and there. But for know, I re-connected the mechanical sender and mounted the gauge in the cabin until I feel like dealing with the factory gauge.

 

[Degnol]

I think you need to use the sender from the original motor. It will mount on the cooler like the later one.

 

[Source3]

I think you need to use the sender from the original motor. It will mount on the cooler like the later one.

Oil sender is gone, went away with the F engine. Forgot to pull it before giving away the engine.

 

[bsmith123]

sender

Yes the sender and the gauge have to match or the readings will be off. the resistance of the sender varies current allowed to the gauge and the needle reading varies accordingly

so now you need a sender to match your gauge or a gauge to match your sender

but your troubleshooting is spot on

 

[maurotrek]

Help! I ordered a replacemnt sending unit for my 81 at autozone (about 40 bucks)... The one I got has a blade for ground. My original one does not. Do I need to get another type or will this work fine??

 

[Solace in Solitude]

8 year old thread!!

Read the post above yours... the sender has to match the gauge and vice versa.

 

[maurotrek]

I think I got it...so if mine does not have the little grounding blade then the new one (that does have teh blade) wont match my gauge....

I think I will just use a universal gauge (they come complete with sending unit and gauge) at autozone for 20 bucks.....

 

[maurotrek]

Hello all, I went back to autozone and returned the 40 dollars unit that had teh grounding blade. I was able to order one that does not have the grounding blade and looks exactly like the one on my 1981 FJ60.... it will take a while to get here...apparently the Hurricane over the Carolinas has messed up shipping time...

thanks for your input!!!! I am still figuring out this forum! Solice in solitude the pictures of your trucks are awesome!

 

[maurotrek]

I installed the new oil sending unit...I put some teflon around the thread it as the old one had some too. My oil gauge now reads correctly!

About 1/2 at idle and the needle goes up as I accelerate