Oil Pressure Reading On Cranking Over

Shaun

Supporter
Hi
Hope this is the right forum, so just wiring my dash and checking gauges, I am using ETB gauges and senders, just testing the all important oil pressure, I am cranking the engine plug less and no ignition, no reading on the gauge. So far I have

1) Checked the gauge rises with an open circuit which it does
2) Bypass the loom and connect direct to the gauge no difference, checked all earths all good.
3) Taken the gauge out and blown into it with a air line, did get a slight resistance change when I did that
4) When I remove the sensor there is quite a build up of oil and pressure in the line so I am sure the pump is pumping
5) My sensor has a warning light connector which earths when the pressure drops below 7 psi and I connected a lamp to that and it lights and dims when I cranking again indicating pressure, does not go out fully though about half dim so maybe 4 psi or so?

I don't have a manual gauge but could get one to test, really I guess I am asking what sort of pressure should a 331 give on a crank stroke, will it show on the gauge, sensor is a 0 to 6 bar, gauge is


I have emailed ETB but not heard back, could be a duff sensor?


Cheers all
 

Ian Anderson

Lifetime Supporter
I have ETB gauges and originally had problems. The answer was I had the connectors on the wrong way round.
changed tem and it worked well. Seem to remember the wiring was done to their instructions but actuslly it was incorrect.

but that was 14 years back.

ian
 

Shaun

Supporter
Cheers Ian, did some more checking, they got back with the ohm reading for zero and full pressure so I can check that, I think its ok just maybe not enough to fully register on the gauge on a starter motor crank but will dig some more, cheers
 

Shaun

Supporter
Good point Bob, I am running a remote cooler with a adaptor so I think (please correct if wrong) that should not affect the flow to and from the filer? Its a thermostatic adaptor so the pipes in the cooler were still dry but I sort of expected that.
Going to see if I have a manual gauge to use if not there are I believe oil pump primer kits for drills? Would not want to us a socket and extension bar in case knowing my luck the socket would fall off !!!!
 
Hi Shaun,

You shouldn’t have any problems getting 2-3 bar oil pressure when cranking for the first time with the spark plugs removed. An oil mechanical gauge is a really good idea.

I would also remove the oil cooler & adapter until you know the basic oil pressure is present, as its less distance (& volume) between the pump & bearings, which you’re trying to protect.

Also, if you remove the distributor and drive the oil pump directly with a primer shaft & drill (as I did) work out which way the pump rotates (as I didn’t!) and wondered why I had no oil pressure! It needs to go anti-clockwise

Regards,

Andy
 

Morten

Mortified GT
Supporter
Hi Shaun, I primed my 351C, killed two drills in the process. On cranking I have 50psi or so.
20/50 mineral Gulf oil. I take it you have an earth lead to sender. I have 3 pins on my VDO. Low light, pressure, earth.
Great fun this:)
Morten
 

Shaun

Supporter
Hi Andy / Morten
I did think I should get a reading, manual gauge the way to go as I don't want to crank any more at risk of damaging the new rebuild. Oil cooler removal a good idea strip it back to basics, the rebuild firm I know spun it up and marked the PSI on the block in white paint.
I guess when you spun it the wrong way you got an oil vacuum :)
Morten mine only has 2 as the case is the earth which is no good as mine is fitted remote but I will make its own earth, not sure I want to kill 2 drills and an SDS may have the wrong effect!!!
More testing later and as you say more fun!!
Cheers all
 

Shaun

Supporter
As the George Michael record said "You Gotta Have Faith"
Not cranking for long enough, so tested the sender with an air line worked a treat with the gauge, put a bag (ok basic stuff here!) over the sender feed hose and cranked, oil slow then flew out, made a mess, cleared that up, put the sender on and voila pressure is showing 40 to 40 psi at crank...Phew
Thanks all....
Now just need to wire my twin trigger dizzy in, sort my fuel transfer valve (put in back to front but have since found a larger bore one so will use that) HT leads, final check and maybe a start....
The sort the gearbox oil leak on my freshly rebuilt UN1 just hoping I don't have to tug it out
Cheers
 

Shaun

Supporter
Shaft seal I think?

Chris Cole who rebuilt the box thinks it needs another O ring? Which part do you mean by the adaptor pins? The roll pins that hold the shafts on?
 
Oil Filters, oil enters filter thru outer set of holes and exits thru the center hole, get that wrong with an ADV ( anti drainback valve ) which Fords have and you wont see pressure. Check the hose layout thru your adaptor etc to ensure they are hooked up correctly as Bob P suggested earlier. Pre fill the filter before you fit it. I just use an old dizzy minus gear with an old 3/8 drive socket tack welded on top and use the 3/8''speed brace to spin it up, you should feel the oil p load come on as soon as it builds pressure. extended cranking on the starter is a bad idea.
 

Bill Kearley

Supporter
IMHO, Remove the distributor and run the oil pump with a drill, anti clockwise to prime your engine and check oil pressure.
 

Shaun

Supporter
Cheers all, I have pressure now!!! Seemed it needed a bit more priming than i was risking, now onto the rets of the bits, why does a to do list just get longer !!
 
Good point Bob, I am running a remote cooler with a adaptor so I think (please correct if wrong) that should not affect the flow to and from the filer? Its a thermostatic adaptor so the pipes in the cooler were still dry but I sort of expected that.
Coolers are non-directional but oil filters have a check valve to prevent reverse flow. Plumb them backward and you get no oil pressure or flow. In a filter, oil always flows from the outside into the center.
 
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