Oil Pressure light - affects running?

[Darren]

Yeah, it's me again!! This is now the last job to sort before getting the car over to MOT. I started the car this morning and it ran very smoothly - fuel pressure is just over 3ft lbs pressure on standard carb. Oil pressure fine on both electrical and mechanical guages. But, then stalled.

The oil pressure light was on all of the time, and I wonder if this was the reason that it stopped? Is there a connection that allows the car to run only if there is sufficient oil pressure? Do I therefore need to get a new oil pressure switch?

Thanks guys - solving this one should then get me to the mot and hopefully the open(ish) road!

Car is a series 1 Monte

Cheers

[Darren]

Update - thanks to a chat with Rodders at the MH and Eric Weston, I confirmed that the pump is cut if the light stays on, which hopefully is the reason the car is stalling. I'll earth the lead and try it before replacing that section of wiring!

[Will]

Darren;
I don't have a Monte wiring diagram in front of me, but on the Scorpion, the switch-to-fuel-pump control is handled by two relays and associated wire(s) on the back side of the sheet metal panel that sits over the RH wheel well.

A much neater solution is to to use the Holley Oil Pressure Safety switch, you can use a metric plig or possibly even the end cut off the old oil pressure switch and retapped to 1/8" NPT to do the conversion and it gets rid of the relays. In my opinion, simpler is usually better, and when it involves losing a couple of old relays and a handful of corroded spade crimps, it's better still!

[Darren]

Hi Will,

You read my mind sir!:) I was looking over everything this afternoon and I completely agree with you. Anything to get rid of unecessary wiring works for me! I think I need to replace the wire run from end to end as I can't seem to get the light to go out! I know I have oil pressure, so for now, I have wired the fuel pump via the coil and if I get time before the MOT tomorrow morning, I'll replace the wiring for the oil pressure switch.

Keep yer fingers crossed for me tomorrow at 10 am - I'm taking my car for it's first MOT since about 1986!!!!

Cheers

[Timo04]

retapped to 1/8" NPT to do the conversion

I 2nd that. This is an excellent solution to loose the relays and extra wiring. BYW: NPT=National Pipe Threads? It's been awhile since I took a machining course.

[Will]

Right, Tim- I wrote "NPT" because Darren's in the UK. They use the Whitworth thread form ,which IIRC is narrower, and I think they use a different taper too, but honestly I don't know as I've never had to actually cut them. The point is, he needs to find himself a 1/8" NPT tap. I think that's pretty easy in the UK, but if not, I have plenty of spares.

[davidb]

NPT = "nominal pipe thread". Sometimes listed as NPTS =
"nominal pipe thread size". I'm a retired plumber and many
dies & taps I used were IPS = "iron pipe size". That being
such as a die to thread black iron gas pipes or galvinized
steel water pipes. Taps or "thread chasers" same, same.
Whether they're S.A.E. I don't know but they sure aren't
metric. Whatever the denomination dies & taps are handy
to have around. A re-thread can save one alot of trips to
the hdwe. store for ONE damn nut or bolt @ a time

[Will]

www.skilledtradesmath.com/files/Threads_and_Thread_Cutting.ppt

A nice powerpoint presentation for you David. And then after you get all that and start to think you have it covered, then you run across another thread form, like Lowenhertz (sp?) that's not even in there.

The more I know, the more I know I don't know. As a teenager, I knew I knew everything. At this rate, I'lll be a vegetable by age 50!

[Timo04]

Thanks guys...this is a great thread! No pun intended.

[davidb]

Thanks Will but I don't have PowerPoint. I just wished to provide
a quick explanation of the abbreviations. Me ain't no expert on
sizing. Metric pitch, thread, diameters, lengths baffle me. I get
by & that's good enough for me. And yes I still make countless
trips for nuts & bolts I don't have.