Oil Pressure Problem?

[Lotus-e-Clan]

if you try it from cold again and the needle stays at 0, tap it to see if the needle IS sticking. None of my excels have ticked over above 1200 ish when on choke either.

Choke isn't needed to raise the revs when cold (as long as it's not too cold) , it's more about optimising ignition advance for leaner mixtures via the TIV. When ambient temp is low the fixed jet mixture is always lean relative to fully warmed. My tickover is optimised for a hot tickover @ 0.5 to 1% CO therefore is set too lean for cold unassisted. However it does respond keenly to (needs) the full vacuum advance that the TIV supplies when cold .

I do use choke initially to start rather than the accelerator pump prime method widely used by many. But as soon as the oil pressure has registered (3 secs or so) I push the choke in and the revs rise and settle @ around 1600 rpm only by virtue of the TIV - choke fully off. When the temp reaches 50 -60 C it drops dramatically to about 950-980 rpm.

But of course I sometimes forget that mine isn't completely std! . Yes 1200 to 1300 rpm is more like you'd expect on a std set-up when the TIV is working as it should... that's what mine ran at before I started experimenting with/developing mine.

Here's a number of possible marginal gains within my system which might account for my relatively high TIV-induced cold tick over @ 1600 rpm :

• • 1) torque release for not running a std water pump. The temperature-controlled EWP is barely turning on start-up so the alternator is 'relaxed' too therefore the engine is running relatively drag free compared to std even though I refitted the PAS a couple of years ago which added back some PAS pump drag.
    2) Maybe Iridium plugs on mine help a tad too - a much more consistent spark delivery contributes to consistent ignition timing delivery.
    3) I run a very large remote high-flow K&N oil filter which reduces drag on the oil pump and..
    4) I'm running 5W50 Valvoline. 5w cold pour viscosity is a lower cold spec than most so less drag on oil systems when cold.
    5) I recently replaced the clutch and I'm running a very light steel flywheel (biggest contribution to raised TIV revs I guess)!! D'oh!!

Even so I think Tanz's cold tick over is far too low mind - and it doesn't have to be that way - on a 89SE MY onwards engine anyway. But like I said, maybe engine earth issues are holding things back.

[CHRISYD]

if I push my choke in before its warm, it nearly stalls so my TIV is buggered?

[Lotus-e-Clan]

if I push my choke in before its warm, it nearly stalls so my TIV is buggered?

Could be a leak in the TIV vac supply hose..or your dizzy vac advance is sticking?

[Lotus-e-Clan]

if I push my choke in before its warm, it nearly stalls so my TIV is buggered?

Could be a leak in the TIV vac supply hose..or your dizzy vac advance is sticking?

Also physical carb imbalance will defo give a rough tickover too ...

[CHRISYD]

all the vac pipes are new and I get the carbs set up once a year, so will look at dizzy vac capsule.

[Tanz]

Im not an electrician so I'll stand corrected on this, but to check the gauge, pulling the wire off the sender should give a full reading as no power can get to ground / earth thro the sender. Grounding the wire should show nowt on the gauge as it all goes to ground. If this is ok than its likely to be the sender and is the easiest / cheapest option to sort. If the sender and guage are good then the oil pressure relief valve cold be sticky, but Im not an expert on these matters so anyone else got a view ?

Bash

Had a look at this the other day. Removing and grounding the wire does exactly what Bash describes above. So that leaves sender and oil pressure relief valve. I removed the sender which has a tiny hole at the end of the bit that screws in. Looked very clean but blasted it with brake cleaner anyway. Also removed and cleaned the engine earth strap so as making a good connection. Seems slightly better - hot idle 3 bar which seems normal for some people on the other thread.
viewtopic.php?f=33&t=10723
Need to change the cam belt when weather gets warmer so will remove oil pump and check relief valve just for peace of mind.

[DavidOliver]

As far as I know the relief valve is part of the oil filter and is not in the pump.
There is a lot on Oil filters on this Forum, worth looking at as you may only need a filter change.

Dave the cog.

[Tanz]

As far as I know the relief valve is part of the oil filter and is not in the pump.
There is a lot on Oil filters on this Forum, worth looking at as you may only need a filter change.

Dave the cog.

As I understand it, the valve in the filter is there to retain oil in the filter, so on start up, oil can be quickly delivered to where it is needed and the oil pressure comes up quickly.

There is a relief valve in the pump that releases excess pressure from the output side of the pump back to the input side. If blocked, can cause excess pressure.

[Lotus-e-Clan]

As far as I know the relief valve is part of the oil filter and is not in the pump.
There is a lot on Oil filters on this Forum, worth looking at as you may only need a filter change.

Dave the cog.

As I understand it, the valve in the filter is there to retain oil in the filter, so on start up, oil can be quickly delivered to where it is needed and the oil pressure comes up quickly.

There is a relief valve in the pump that releases excess pressure from the output side of the pump back to the input side. If blocked, can cause excess pressure.

There are up to TWO valves in a disposable spin-on cartridge oil filter.
1) an anti-drain-back diaphragm
2) BLOCKED oil filter relief valve

Most have 1) - all have 2).

The blocked filter relief valve opens if the matrix is dirty/blocked to allow UNFILTERED oil to reach the bearings. It also opens in cold weather on new, clean, filters IF the viscosity of the oil is too thick to flow through the matrix on start-up. Modern filter matrices are nearly ALL specified for modern thin oils (10w/40 and thinner) - so in very cold weather 20w/50 oils and thicker will open the cartridge blocked relief valve allowing UNFILTERED oil to reach the bearings (bad!- that's why I opted to run 5w/50 in the Excel).

The OE oil pump pressure relief-valve is built into the engine oil gallery system and operates independently to cartridge oil filter valves. The big difference here is that the excess oil pressure is vented direct to sump and NOT through the bearings!

[DavidOliver]

For Peter K.
When I have had the engine oil gallery opened up, including the grub screw on the front of the engine, i never saw any valve looking mechanism, springs and ball bearing. As I like to be sure that oil galleries are completely cleaned out can you tell me the location of this relief valve?

Dave the cog.

[Lotus-e-Clan]

For Peter K.
When I have had the engine oil gallery opened up, including the grub screw on the front of the engine, i never saw any valve looking mechanism, springs and ball bearing. As I like to be sure that oil galleries are completely cleaned out can you tell me the location of this relief valve?

Dave the cog.

Hello Dave in warm sunny Spain! Never been there but I wish I was there at the moment - it's cold here!

The oil pressure relief valve is actually within the pump housing - I used the term 'oil gallery' too loosely. Sorry.

Quote from Service Notes SECTION EA Page 3:

• • The lubrication system is of the forced feed type, the oil being circulated by a mechanically driven oil pump. The pump, of the eccentric bi-rotor type which incorporates a non-adjustable plunger type relief valve, is driven by an auxiliary shaft this being contained in the auxiliary housing bolted to the right-hand side of the cylinder block.
    
    Oil is drawn from the sump up a pick-up pipe and into the pump. When the relief valve opens, oil is passed back into the inlet side of the pump (sump pick-up pipe). From the pump the pressurised oil flows through the oil cooler and full-flow filter to the oil gallery.

[Pete Boole]

Peter's right - the valve is in the casting that also holds the distributor shaft - the casting which bolts over the pump gears. On my early engine the valve is held in place with a steel plug that doesn't appear to be removable, not sure if it the same on later engines. No idea how you are supposed to clean it properly!

Pete

[Tanz]

Peter's right - the valve is in the casting that also holds the distributor shaft - the casting which bolts over the pump gears. On my early engine the valve is held in place with a steel plug that doesn't appear to be removable, not sure if it the same on later engines. No idea how you are supposed to clean it properly!

Pete

Hi Pete - don't suppose you have a picture by any chance? Is it worth removing the oil pump if it can't be cleaned?

[barker_001]

I don't have a picture but this was from a thread a while back when I had oil pressure problems:
"The relief valve is in the oil pump housing, you can only see it when the housing is removed. The end of the piston is visible as a circular recess, on the face of the housing, about 10mm in diameter. You need to poke it fairly hard with a screwdriver or similar to see it move, and prove that it is operating correctly."

I spoke to Steve at SJs about it at the time, and he said it's just a piston with a spring behind it, and he'd never seen one go wrong.

[Pete Boole]

Hi Phil. To clean the valve properly you need to remove it. This can be done using a press. The valve is held in place by a steel or aluminium pressed-in plug (with O-ring). If this is carefully pressed out it can be cleaned and the spring length/condition checked. I'll take a couple of photos tomorrow.

Pete