MPG Problem - may be solved!

Post by **grahamt7** » Tue Apr 03, 2007 10:49 pm

The mog is in dry dock this week..........and I've asked that the mog people investigate the low mpg that I get. They reckoned that I should get 35-40mpg as standard, and 50mpg on a run. This does not compare well with the 23-25 mpg that I am getting.

Anyway, the upshot is that they stripped the carburetter and my 1098 has a carb needle from a 948

!!

The thing has been rebuilt, and apparently the car "sounds completely different". Should hopefully be much better - can't wait to pick her up (complete with shiny gauges!).

Post by **grahamt7** » Tue Apr 03, 2007 11:37 pm

Gawd - I've been moved from General Discussion - not entirely necessary I think.

Hey ho.

Post by **Onne** » Tue Apr 03, 2007 11:41 pm

It is a mechanical issue though Graham, and I am sure there are just as many people reading this section as there are people that read GD

Post by **grahamt7** » Tue Apr 03, 2007 11:44 pm

I did have a sneaky feeling that I'd been Onne'd!!!!!

And strictly speaking, you are right - and I do hope that starting Thursday I can confirm that it was indeed mechanical - a case of some muppet fitting the wrong bits to the carb!

Post by **Onne** » Tue Apr 03, 2007 11:47 pm

It wasn't me, but I agree fully with the decision, as it makes it easier for all people to find the topic they were looking for.

I hope you get it sorted though, but I can't see how the needle only can make such a difference.

(very nice to see my car on you photslide btw

:D)

Post by **bigginger** » Tue Apr 03, 2007 11:49 pm

No. it wasn't

BG

Post by **grahamt7** » Tue Apr 03, 2007 11:50 pm

I think there was also some mention that other parts of the carb had also been replaced with some 948cc bits. Some jet or other (doesnt mean a whole lot to me), but as a result the old mix was running rich apparently. It's als had new plugs today (apparently the ones fitted were designed to work at a different operating temperature).
Still itching to get the old girl out and about.

Post by **grahamt7** » Tue Apr 03, 2007 11:52 pm

OK OK, will the REAL topic-mover please stand up?

Post by **Onne** » Tue Apr 03, 2007 11:52 pm

I guess it all adds up!

Post by **bmcecosse** » Wed Apr 04, 2007 7:48 am

The 948/1098 carb bits are almost identical - this is just 'waffle' you have been given. The engine may very well have been running rich - and new jet/needle etc will bring it back to standard spec - but I seriously doubt you will ever get 50 mpg - maybe 40 on a gentle long run over basically flat roads!

Post by **Roni** » Wed Apr 04, 2007 9:06 am

Sometimes Minors can do strange things. Many years ago I had a knackered old 948 (my first Minor). On a trip from Timaru to Christchurch at the speed limit, 80k then,on a very flat road, a cool evening with little traffic I was a little surprised when I filled up. I had just done 100 miles exactly and could only put in 1.6 gals of petrol. 62.5mpg. Never been able to get that again on any car.
My current 1098 is getting around 40mpg in combined town and country running. Recently getting the mixture right, different needles etc, made a difference of 8 - 10 mpg. It felt ok before but now is a lot better and has no flat spot on acceleration either.

Post by **rayofleamington** » Wed Apr 04, 2007 8:30 pm

It may well have been me - to be honest i'm not 100% sure. I often move threads into the technical sections where they should be, or move wanted ads into the wanted section etc. etc...

Post by **grahamt7** » Wed Apr 04, 2007 11:07 pm

tank filled..........did 26 miles......no movement of needle..........nothing to report on the MPG so far.......

but the gauges are lovely!!!! 3000 rpm at an indicated 50mph

14 volts being delivered.........

water temp around 80 degrees when engine is nicely hot

oil pressure 50psi cold, 35 (if i remember correctly) when warm

and the engine sounds sweet too!!!

Post by **bmcecosse** » Thu Apr 05, 2007 7:38 am

If that's the running oil pressure at speed then it's way low ! Change the oil and filter and use 20W 50. If it's the idle pressure - then it's fine !

Post by **grahamt7** » Fri Apr 06, 2007 10:46 pm

107 indicated miles, 50% motorway, 50% town, reading a fraction less than half a tank left.....

Further update when it's time to fill up........

Post by **grahamt7** » Wed Apr 11, 2007 11:06 pm

Things are looking up...........

Ran a few miles since the engineeering works......

Used 22 litres to cover 148 miles, or 30.54 mpg.....

About 50% on the motorway, and about half of that at 60mph or above, other 50% stop start town stuff!! On my calculations there would be another 50.5 miles left in the tank (although the tanks would be somewhat dry by that time!!).

Just waiting for long run (might have to wait till the 7th of July!).