Sudden drop of oil pressure

Re the white yellow stripe 2 wires into the the connector- I could be wrong but the diagram shows a connector for the white yellow after it leaves the starter motor. I think it could be this connector re I don’t think anything else is supposed to be connected to it. I think one end comes from starter motor to this connector then the other from this connector to the coil. Which then joins the other white yellow wire from the ballast resistor (ignition feed). The wiring does not suggest any other wire should be connected and I think I can make out that both those 2 wires are white with yellow stripe. If when you check colours of this connector you find one is infact white no stripe and other is as can be seen white yellow then it could be that this is where the ballast resistor was - on the drawing the feed to the ballast is white and from ballast to coil is white yellow stripe. Pretty sure mine does not have that connector coming out loom like this so could be your loom been modified for new electronic ignition and ballast removed. Will wait see what you find out when check wire colours and a voltage check should show 12v at coil when ignition on rather than 6v.

Dave
 
DaveRover3500s said:
. Most systems in market are the straight fit points replacement type so you could have that see what your info for it says. The ballast resistor I believe is in the loom about 300mm up from coil - and joined there somewhere- mine was.

Dave
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Mine is a powerspark system, which came as a complete distributor and coil. The system on it before was also powerspark but just had a replacement part inside the original dizzy.

I think you could be right in your next post and the ballast has already been removed. If it looks the same as the one on my series landy for the glow plugs, essentially a spring that glows red hot, then it's definitely been removed.
 
The ballast on the P6b is a length of resistive wire buried in the loom, the wire from the starter is the ballast bypass at battery voltage, albeit reduced by the starter demand.

If you want 12V for an electronic ignition system you need to run a separate wire from the ignition switch, ie. not the nearby washer pump supply because that is fused, if the fuse blows because of something else on that circuit you then lose the engine, then you are left fault finding that usually on a dark rainy night.
 
colnerov said:
The ballast on the P6b is a length of resistive wire buried in the loom, the wire from the starter is the ballast bypass at battery voltage, albeit reduced by the starter demand.

If you want 12V for an electronic ignition system you need to run a separate wire from the ignition switch, ie. not the nearby washer pump supply because that is fused, if the fuse blows because of something else on that circuit you then lose the engine, then you are left fault finding that usually on a dark rainy night.
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I measured the voltage on the coil +'ve with the engine running and got 12V. The coil -'ve measured 10V. I presume that's the stabilised voltage from the instrument panel to the tach?

Funnily enough, the 12V supply for the electronic dizzy is from the washer pump, which I don't like, but as I said, I wired the new one like for like.

There is a separate chunky brown wire that's been added in and run from somewhere around the fusebox - I'd have to look and see if it's fused or unfused - it currently has a "temporary" feed to the brake lights wired in. Perhaps I should swap them round.

Something in my head is telling me it's a permanently live though, which is why I put the brake lights on it until I can figure out where the problem is with the proper feed to the brake switch.

I need to find out what is causing the engine to run like a dog again and not manage my hill. It has to be fuel related, possibly pulling air in somewhere.

I still need to get the tank nice and empty and re-pipe the whole thing in solid runs and swap the reserve and main lines around. If rather take fuel from the bottom of the tank with a strainer than from a few inches up with an open end.

If I do away with the reserve line altogether, I can pipe the return in a single run and just have two fuel pipes all in copper, with no joins except the unions at either end
 
As Colnerov says either you need to run a new wire on to the white non fused ignition feed wire - or, as was done on my car, un peel the loom tape right back to where the white wire connects to the ballast resistor wire, remove the ballast resistor wire and connect a new white wire (to keep wire colour consistent) down to the coil which kind of does away with the starter coil feed arrangement by default. As Colnerov also says the washer bottle pump feed is not the way to go! That’s quite a lazy way to have provided a feed for your powerspark system but as you say not your doing. Pretty sure the regulator in the dash has nothing to do with rev counter or coil 10v that’s only for the temp gauge and fuel gauge - I think!

The brake lights are fed via a green wire from fuse 19-20. The back of fuse box has at least 3 wires coming out the fuse box at the output side (bottom) of this fuse - another green from this fuse feeds the washer res washer motor- interesting that this circuit has had extra load on to it via powerspark ignition wired to the green wire feeding the washer motor - and now the brake lights don’t work which come off the same circuit also a green wire which goes to the brake switch on drivers side on the inner wing just back from the brake servo.

Is it too much of a coincidence?!


Certainly need to look behind fuse box and see what’s happened or check feed via green wire to brake switch should have 12v soon as ignition is on.

Dave
 
DaveRover3500s said:
As Colnerov says either you need to run a new wire on to the white non fused ignition feed wire - or, as was done on my car, un peel the loom tape right back to where the white wire connects to the ballast resistor wire, remove the ballast resistor wire and connect a new white wire (to keep wire colour consistent) down to the coil which kind of does away with the starter coil feed arrangement by default. As Colnerov also says the washer bottle pump feed is not the way to go! That’s quite a lazy way to have provided a feed for your powerspark system but as you say not your doing. Pretty sure the regulator in the dash has nothing to do with rev counter or coil 10v that’s only for the temp gauge and fuel gauge - I think!

The brake lights are fed via a green wire from fuse 19-20. The back of fuse box has at least 3 wires coming out the fuse box at the output side (bottom) of this fuse - another green from this fuse feeds the washer res washer motor- interesting that this circuit has had extra load on to it via powerspark ignition wired to the green wire feeding the washer motor - and now the brake lights don’t work which come off the same circuit also a green wire which goes to the brake switch on drivers side on the inner wing just back from the brake servo.

Is it too much of a coincidence?!


Certainly need to look behind fuse box and see what’s happened or check feed via green wire to brake switch should have 12v soon as ignition is on.

Dave
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The coil is getting 12V so presumably the ballast resistor has already been done away with?

The brake lights never worked since I got it until I put the temporary feed in. There are zero volts at the switch. All the wires coming off the fusebox have power, so I am guessing the wire is damaged at some point in the loom.

As I said in my previous post, there is an additional wire which has been fed from the fusebox down the inner wing and is currently doing the temporary brake light feed. I think it is unfused and permanently live, I'll need to investigate, but I will change this to the Powerspark feed and ignition switched to get it off the washer pump.

Is there any reason I couldn't power it off the spare +'ve terminal on the coil given it's getting 12V not 6V?

I'll go through the loom from the parts car and trace out the brake light wire to get my head round the routing and so on and maybe make some progress on why it's not getting power.

As for the hill. Coming back from the shop, it did the same, died off completely but I managed to get it up the hill keeping my foot on the floor and slipping the clutch in first gear. Power restored when I got onto level road.

I forgot to buy dog food (the whole reason I went to the shop) and had to go out again. Coming up the hill (always at same bit) engine died completely and cut out. Started again after about 7 or 8 seconds cranking and limped back home.

I'm almost sure the problem is just fuel level. Empty should be level with the top of the pick up but the needle isn't right at the bottom. Accelerating up the hill (it's a steep hill) could be sloshing the fuel around enough to expose the top of the pick up and pull air.

If I get time tomorrow, I'll drain the tank and sort the pipes out, even if it's just swapping the reserve and main pickups around. I've got a suspension job to do on another car first. I invariably get covered in fuel and lose several gallons on the ground every time I go near those pipes so I'm not looking forward to it.
 
Ha yes thanks for confirming. Green wire is dead at the brake switch so could be where it splits behind fusebox?
Since your now not using ballast and the 12v at the coil is I assume, the original feed extended from the white wire that fed via the ballast resistor to the coil then yes I think that’s much better option than feeding the powerspark from the green wire washer motor feed for reasons Colernov says. Pretty sure that’s how my electronic ignition is fed. Needs to all stay on white wire feed.

Any new wire that’s not fused anywhere I would fuse for sure the risk of a short circuit is always there and with no fuse it could/will be catastrophic!

Dave
 
Your going up hill problem sounds very much like vapour lock. Common with the mechanical fuel pump. Try going up your hill with the car stone cold. second thing to do is park car on hill in the area it doesn't run properly. open bonnet and remove the carb bells one at a time. look down the little hole in the middle. There should be fuel showing right across opening between 1/16" and 1/8" below the top brass ring. anything significantly lower means fuel isn't getting to the jet from the fuel bowl. That can be caused by vapour lock or incorrect float needle height. The latter is very important to be set correctly as it affects the mixture.

Putting an electric pump in the engine bay won't necessarily fix vapour lock. It needs to go next to and under the tank. A much cheaper first attempt to fix is to put a restrictor in the fuel return line to give a little more line pressure and a little less hot fuel going back to the tank.

Remember with the fuse box, to check a fuse you need to test all six points individually, with the fuse in and the fuse out - thats twelve tests all up - each individual tab (x4) and the two ends of the fuse. Tabs need to be checked pressing away from the fuse ie. outward.
 
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mikecoombs said:
Your going up hill problem sounds very much like vapour lock. Common with the mechanical fuel pump. Try going up your hill with the car stone cold. second thing to do is park car on hill in the area it doesn't run properly. open bonnet and remove the carb bells one at a time. look down the little hole in the middle. There should be fuel showing right across opening between 1/16" and 1/8" below the top brass ring. anything significantly lower means fuel isn't getting to the jet from the fuel bowl. That can be caused by vapour lock or incorrect float needle height. The latter is very important to be set correctly as it affects the mixture.

Putting an electric pump in the engine bay won't necessarily fix vapour lock. It needs to go next to and under the tank. A much cheaper first attempt to fix is to put a restrictor in the fuel return line to give a little more line pressure and a little less hot fuel going back to the tank.

Remember with the fuse box, to check a fuse you need to test all six points individually, with the fuse in and the fuse out - thats twelve tests all up - each individual tab (x4) and the two ends of the fuse. Tabs need to be checked pressing away from the fuse ie. outward.
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I put the mechanical pump in to solve this problem originally as I had fitted an electric pump initially when I was trying to get it to run.

Would vapour lock not affect it on the level too?

It does only do it when it's hot but the engine is generally hot by the time it gets to the bottom of the hill anyway. Unfortunately, it's a single track road, so not really suitable for stopping and footering with the carbs. Lots of silage being cut just now so tractors running up and down constantly.
 
DaveRover3500s said:
yes I think that’s much better option than feeding the powerspark from the green wire washer motor feed for reasons Colernov says. Pretty sure that’s how my electronic ignition is fed.

Dave
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That's much easier than trying to repurpose that extra wire that's been added in. I wasn't sure if the coil supply would cause interference with the electronic ignition.
 
If it's vaporisation a pump can't suck vapour, mechanical or electric, I tried an electric pump up front by the washer bottle,( although I did re-route the pipe along the inner wing and insulated it) but still had problems. Mainly because the fuel supply pipe goes over the top of the bellhousing and then is fixed to the side of the block so it soaks up all the heat. So moving the electric pump to the rear under the tank so it gets a supply of liquid petrol, and then re-routing the pipe away from heat sources under the car. Saab solve this problem by routing it and the brake pipes inside the car, away from damage primarily I think.
 
colnerov said:
If it's vaporisation a pump can't suck vapour, mechanical or electric, I tried an electric pump up front by the washer bottle,( although I did re-route the pipe along the inner wing and insulated it) but still had problems. Mainly because the fuel supply pipe goes over the top of the bellhousing and then is fixed to the side of the block so it soaks up all the heat. So moving the electric pump to the rear under the tank so it gets a supply of liquid petrol, and then re-routing the pipe away from heat sources under the car. Saab solve this problem by routing it and the brake pipes inside the car, away from damage primarily I think.
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It wasnt managing up the hill with the electric pump and I diagnosed it to fuel starvation. The 80 gallon per hour capacity of the pump turning out to be chinese gallons.

It's been fine ever since with the mechanical pump and has only become an issue with the fuel level close to empty which is why I'm thinking the gauge isn't hugely accurate and I'm pulling air. My theory will be proved or disproved once I've rerouted the pipework. Job for tomorrow, been too busy today to look at it. I'm certainly not discounting vapour lock though but I'm changing the pipes anyway to get the extra capacity and get rid of all the joins in the reserve and return pipes so no extra work involved.
 
I too think fuel and vapour lock. I changed my fuel pump to a decent facet pump under the tank and never had a problem - it had a fake Chinese facet pump there and it packed up on me. On a hill engine is doing more work and things like ignition timing are so so important on the V8 Rover. Couple degrees out she heads up faster and on hills really effects it. It took a rolling road session to get mine bang on - only 6 bhp more but she ran so much better and cooler on the hills.

Dave
 
That said once you sorted your pipe work and the fact you may have a low tank I guess it’s possible your sucking air - are you using the reserve feed or main feed- hopefully reserve feed as that comes off bottom of tank and less likely to be sucking air. If your sucking from main feed which is couple gallons up the tank then it’s defo possible.

Best luck you will get there and the prize of an up hill run under acceleration will be worth it!

Dave
 
I wrote a reply yesterday but it didn't post.

Today I braved the heat and changed the pipework round. Using the electric pump which is still in the engine bay, I reattached to the original fuel pipe, switched the reserve tap to reserve and pumped out the tank after putting the car on the ramps.

Whether or not I was pumping air is still in the air because I pumped out at least 3 gallons, however, with an empty tank, I removed both pipes including the reserve/return line.

I put the fuel feed onto the reserve position and did away with the reserve/return altogether and piped the return straight to the main feed position.
20260709_180338.jpg
I swapped the distributor supply onto the spare 12V terminal on the coil and went for a drive.

It was awful, kangarooing, bucking and cutting out. The tach was jumping all over the place as well, so I pulled over and wired the dizzy back into the washer pump feed.

The car drove well after that but still a bit juddery at very small throttle opening, 30mph in 4th essentially. It drove beautifully at bigger throttle openings though and pulls well.

Coming up the hill it pulled strongly all the way up without any issues. The weather was extremely hot today, mid to high 20's so possibly not vapourisation.

I'm still not 100% convinced there isn't a vapourisation issue and I just got lucky today because I put half a tank of fresh cold fuel in but at least I know I havent got a million joints in my fuel lines and have a decent amount of time to refuel when the gauge reads empty. Id like to get the low speed jerkiness fixed, this is probably down to carb adjustment.

Most importantly, I can drive it again. Just in time for one of the biggest shows in Scotland this weekend at Glamis Castle.
 
Here is Australia for the most part, mid to high 20s is warm, certainly not hot. Mid to high 30s or low 40s is what we call hot. I can drive around in that sort of ambient temperature using the mechanical fuel pump and experience no vapourisation. Park the car, return after 30 minutes or less and it starts straight away. No hesitation at all. From my experience across 41 years of driving the same P6B, vapourisation has far more to do with the fuel specification than anything else. Of course, different countries have different specifications, and we all have to deal with our local conditions.

Ron
 
erubus said:
I wrote a reply yesterday but it didn't post.

Today I braved the heat and changed the pipework round. Using the electric pump which is still in the engine bay, I reattached to the original fuel pipe, switched the reserve tap to reserve and pumped out the tank after putting the car on the ramps.

Whether or not I was pumping air is still in the air because I pumped out at least 3 gallons, however, with an empty tank, I removed both pipes including the reserve/return line.

I put the fuel feed onto the reserve position and did away with the reserve/return altogether and piped the return straight to the main feed position.
View attachment 28712
I swapped the distributor supply onto the spare 12V terminal on the coil and went for a drive.

It was awful, kangarooing, bucking and cutting out. The tach was jumping all over the place as well, so I pulled over and wired the dizzy back into the washer pump feed.

The car drove well after that but still a bit juddery at very small throttle opening, 30mph in 4th essentially. It drove beautifully at bigger throttle openings though and pulls well.

Coming up the hill it pulled strongly all the way up without any issues. The weather was extremely hot today, mid to high 20's so possibly not vapourisation.

I'm still not 100% convinced there isn't a vapourisation issue and I just got lucky today because I put half a tank of fresh cold fuel in but at least I know I havent got a million joints in my fuel lines and have a decent amount of time to refuel when the gauge reads empty. Id like to get the low speed jerkiness fixed, this is probably down to carb adjustment.

Most importantly, I can drive it again. Just in time for one of the biggest shows in Scotland this weekend at Glamis Castle.
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Some good work there! Odd that it did not like the 12v coil supply for your electronic ignition supply? You should defo feed the electronic ignition from the white ignition wire circuit at some point for reasons already covered there should be no reason for it to not operate correctly from this feed.

Your nearly there - agree once it’s fully in tune and as it should be your low down power should be on button. I bet you enjoyed the up hill run after all that work!

Dave
 
SydneyRoverP6B said:
Here is Australia for the most part, mid to high 20s is warm, certainly not hot. Mid to high 30s or low 40s is what we call hot. I can drive around in that sort of ambient temperature using the mechanical fuel pump and experience no vapourisation. Park the car, return after 30 minutes or less and it starts straight away. No hesitation at all. From my experience across 41 years of driving the same P6B, vapourisation has far more to do with the fuel specification than anything else. Of course, different countries have different specifications, and we all have to deal with our local conditions.

Ron
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Scottish heat hits different, it rains pretty much constantly so when the sun comes out it's oppressively close and clammy. Please more of a problem to the human body than a car though. I'm perfectly happy at 40° on a Mediterranean island but 18° in Scotland and I'm sweating like a w***** **** in a half price sale as the saying goes.
DaveRover3500s said:
Some good work there! Odd that it did not like the 12v coil supply for your electronic ignition supply? You should defo feed the electronic ignition from the white ignition wire circuit at some point for reasons already covered there should be no reason for it to not operate correctly from this feed.

Your nearly there - agree once it’s fully in tune and as it should be your low down power should be on button. I bet you enjoyed the up hill run after all that work!

Dave
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I wonder if it was getting interference or something. I'm fairly sure the problem was ignition related as the tachometer was jumping around at the same time. I might have made a bad spade connector but I doubt I could have done it that bad. Changing back to the washer feed certainly cured the problem well enough to make it useable.

I need to concentrate on getting the spare engine rebuilt. I still haven't even got it on the engine stand!

You're right, the road up my hill is set into a dip with about an 8 foot height difference on the right, so you get the engine noise blasting right back at you through the open window. Glorious in the Rover, the V6 Audi and even the MX5 hill climb car. The land rover just trundles up sounding like a tractor, the company car (Kia Sportage) sounds like a skeleton having a wank in a biscuit tin and the sprinter sounds like a bus.
 
just a thought if the coil is polarity reversed you can run for ages trouble free then it starts an stops
in a array of what the heck is going on you get out kick the tyres and hey she starts again ready to fail again
just when you dont want to
its an old problem but often not considered dizzy to the coil neg ign to coil pos

most electronic modules do need a 12v non ballasted feed or with a low battery state and a ballast feed they can be
below the base operating voltage of the module coupled with 1.5ohm ballasted coil or 3 ohms for a full 12v feed

a cheap and easy check
Pete
 
erubus said:
I wrote a reply yesterday but it didn't post.

Today I braved the heat and changed the pipework round. Using the electric pump which is still in the engine bay, I reattached to the original fuel pipe, switched the reserve tap to reserve and pumped out the tank after putting the car on the ramps.

Whether or not I was pumping air is still in the air because I pumped out at least 3 gallons, however, with an empty tank, I removed both pipes including the reserve/return line.

I put the fuel feed onto the reserve position and did away with the reserve/return altogether and piped the return straight to the main feed position.
View attachment 28712
I swapped the distributor supply onto the spare 12V terminal on the coil and went for a drive.

It was awful, kangarooing, bucking and cutting out. The tach was jumping all over the place as well, so I pulled over and wired the dizzy back into the washer pump feed.

The car drove well after that but still a bit juddery at very small throttle opening, 30mph in 4th essentially. It drove beautifully at bigger throttle openings though and pulls well.

Coming up the hill it pulled strongly all the way up without any issues. The weather was extremely hot today, mid to high 20's so possibly not vapourisation.

I'm still not 100% convinced there isn't a vapourisation issue and I just got lucky today because I put half a tank of fresh cold fuel in but at least I know I havent got a million joints in my fuel lines and have a decent amount of time to refuel when the gauge reads empty. Id like to get the low speed jerkiness fixed, this is probably down to carb adjustment.

Most importantly, I can drive it again. Just in time for one of the biggest shows in Scotland this weekend at Glamis Castle.
Click to expand...
I may be a bit behind with the story here, but If you piped the return from the carbs onto the former feed outlet at the tank using full bore copper pipe without any restrictor then you may have created a very nice pumped loop of fuel that may prefer to go round in a loop rather than feed the carbs.
The original return pipe had a restrictor with a tiny hole in it where it T'd into one of the pipes that exited the tank. you should be able to find it if you unscrew the original return pipe at the tank end.
 
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