Help, no oil pressure .

[mobylette]

I have just refitted my rebuilt engine. Cranked over with ignition disconnected until the oil pressure light went out, which it did after a minute or so. Connected ignition, fired up and now the oil light stays on! What can be the problem, pressure release valve, pressure switch? I was going to fit a pressure gauge, but supplied adaptor turned out to not to suit oil pipe.

[oliver90owner]

Can’t help with the problem - could be lack of pressure or a dodgy switch. Finding which it is will be your first task. Alternatively, prime the oil gallery, via the oil pressure switch drilling, and try again.

Just posting to say don’t just disconnect the ignition system and engage the starter motor - remove the plugs to reduce the load on the starter motor and engine bearings.

[mobylette]

Thanks, have just primed the pump via the priming tapping on the block, no difference. Oil pump was primed with grease on assembly as advised. Only other points to mention, screw on oil filter fitted. I did not fill this with oil before fitting, could this be a cause? The oil level does not seem to have gone down to indicate filter has filled up. Light goes out if wire disconnected from switch.

[mobylette]

Update, removed pressure relief valve to clean, no visible dirt. In the process the connection on the oil pressure switch broke off, so fitted used one I had spare. Took plugs out, span engine, light goes out . Plugs back in and all appears well. Engine starts, light goes out, sounds nice and smooth. Fingers crossed no damage.

[philthehill]

Well done.

For future reference and general information:-
Always prime the oil pump. If a 1275cc engine or other engine without the priming plug reverse prime through the oil filter feed.
Always leave the plugs out when initially starting up so as to relieve the pressure on the crankshaft bearings. Only fit the plugs when you have oil pressure.
If installing a screw on filter assy - fill the oil filter body before fitting.
When assembling an engine I always smear everything in engine assy lub as it does help in reducing skidding or damage to the bearings and other moving interfaced surfaces.
Phil

[ampwhu]

I was always told to pack a new oil pump full of vasoline before assembly. dissolves into the engine oil when warmed up.

[mobylette]

Thanks for the advice Phil. Have just been for a spin around the block and everything seems fine. The upgraded HS4 carb needs fine tuning, but I am feeling mighty relieved that the oil pressure problem is resolved, I had visions of taking the engine out again. Cheers, Martin.

[philthehill]

ampwhu
Even if the oil pump has been filled with Vaseline or other lubricant the oil pump should still be primed.
Until the Vaseline it has melted away full oil suction, pumping and circulation will not be obtained.
That is why I always use engine assembly lub and prime the oil pump before removing the plugs and turn the engine over on the starter motor until full oil pressure is achieved - plus an additional 30 seconds turn over which allows for the oil to reach all around the engine.
Only then do I fit the plugs and start the engine.

Martin
Good result!
The 'A' Series is a tough old engine but better to have full oil circulation before compression and start up.
Phil

[mobylette]

OK , next question. I have fitted an HS4 carb originally specified for a mini. I have the engine running and ticking over smoothly, and have adjusted the mixture using the lifting pin. Dashpot topped up with 3 in 1 (Is this oil too thin? I believe it should be SAE20). On a test drive and once warm, the engine splutters coming off idle and then accelerates smoothly. I believe this is the piston rising too fast in the carb giving a momentarily weak mixture. Advice seems to be thicker oil in the dashpot, but I would think a heavier spring would be the way to go. Any thoughts?

[philthehill]

Try engine oil 20W/50 oil first and see if there is any improvement.

[mobylette]

Will do tomorrow morning, and report back.

Thanks
Martin

[ampwhu]

ampwhu
Even if the oil pump has been filled with Vaseline or other lubricant the oil pump should still be primed.
Until the Vaseline it has melted away full oil suction, pumping and circulation will not be obtained.
That is why I always use engine assembly lub and prime the oil pump before removing the plugs and turn the engine over on the starter motor until full oil pressure is achieved - plus an additional 30 seconds turn over which allows for the oil to reach all around the engine.
Only then do I fit the plugs and start the engine.

I do exactly the same! the reason for the Vaseline is was told, is because after rebuilding an engine, most people wont fir it straight away. the engine sits around for a while. Vaseline will stay in the oil pump until start up.

Martin
Good result!
The 'A' Series is a tough old engine but better to have full oil circulation before compression and start up.
Phil

[les]

Wonder where this Vaseline idea came from, filling the pump with oil is the idea, and priming the system does that!

[philthehill]

Les

There is a mention in the link below as regards Vaseline but note the preferred use of 20W/50 engine oil to prime the pump and the wide use of engine assembly fluid.
https://www.calverst.com/technical-info ... oil-pumps/

Phil

[les]

I'll hang on to that link Phil. It looks old school!

[mobylette]

OK, removed the 3 in 1 from the dashpot and refilled with engine oil, spluttering gone, nice and smooth pick up from idle . Thanks for the advice

New problem. I have just filled up with petrol. Ignition on and the gauge moves from it's stop to the "Empty" mark and stays there except when I indicate right, when it flips between empty and full in time with the flasher. Only right, not left. I had the passenger glove box liner out to replace the choke cable with a longer one. I presume I have disturbed some wiring. Any clues? The indicators are working properly.

Have just had a thought, a PO had for some reason cut through the main loom and rejoined with choc bloc connector. While the engine was out I tidied this up and remade the connections with bullet connectors. I may have swapped a wire round. Will check.

[mobylette]

I must now admit to making a very silly mistake with the wiring When I bought the bullet connectors I ordered single and double connectors, thinking that the doubles were two singles in one rubber insulator, WRONG!. I have just checked and these are Siamese connectors, so god knows what I have connected up together, luckily no smoke has escaped, so my job for this afternoon will be to replace all the doubles with two singles.

[philthehill]

You can get twin and three (and possibly more) Ripaults (they originally made them) connectors that are insulated between the metal sleeves.
If using Ripault connectors it is best to use the correct soldered connectors on the end of the wire.

[mobylette]

Thanks Phil

So the connectors have been swapped and now the fuel gauge (and all the other electrics) are back to normal. I bought a set of bullets to suit 3 different wire gauges and a (very expensive) crimping tool designed for them. It works very well. I will purchase the 3, or I think I may have seen 4 way Ripaults and tidy up the wiring later.

Cheers
Martin

[philthehill]

Martin
I have one of the original Ripaults nipple crimping pliars Pt No: SSCT 1 and a pair of Ripaults bullet pliars for inserting the bullets into the connectors.
Expensive yes but well worth every penny.
The secret with the pliars is not to squeeze too tight as the brass connectors are easily deformed which then gives problems when inserting the bullet into the connector.
Whilst the pliers are good you cannot beat a soldered nipple on the end of the wire.
Phil