Classic cars forum & vehicle restoration.

[Jim.Walker]

Since this problem was first posted, I discovered that I could close the distributor points on my Triumph Motorbike by around 10 thou by rocking the cam. Curing that, which is another story, has given a fuel saving of nearly 20 mpg over a 700 mile check.
Curiously the improvement in performance I expected did not materialise, but then I had no complaints about performance in the first place. Still if you class fuel consumption as performance the improvement was rather dramatic.
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[Finch661]

thanks for the replies. I have redone the timing, and is set up ok. Haven't checked the vacuum advance unit, though when the car was tuned last year, one thing the mech said was the vac advance unit was pied. I replaced it mind you.... the only mod to the dizzy is that i replaced the points with an electronic module thingy.

something i did notice is that when i jump in the car the next morning, the petrol gauge appears to have dropped slightly, making me thinking its a leak. also i did smell fuel when i was sitting in traffic, but it could just be the overflow?

if its a leak, then by replacing the main fuel line (tank to engine bay), then it may lie from line to pump/pump to carb. i am replacing the fuel pump and will replace the other fuel pipes, and see how that goes
_________________
1985 Mini Mayfare (1275)
1976 Mg Midget 1500

[Nic Jarman]

The Midget has a flat top to the fuel tank and because of corrosion I had to replace mine. Does the back of your 1500 smell of fuel but there is none to be seen?
_________________
1936 Morris 8 Series 1
1973 MGB roadster
1977 MG Midget 1500
Dax Rush

[Jim.Walker]

[Finch661]

hi nic, i replaced my tank last year, and there is no smell of petrol coming from the back.

Jim: you might be on to something there. when the car was tuned (with the britpart module), the timing was set up as by haynes. would the timing marks of the car change because of the electronic module?
_________________
1985 Mini Mayfare (1275)
1976 Mg Midget 1500

[Jim.Walker]

[Finch661]

a trick i learnt with the module (regarding static timing) was to listen for the click in the module (i am guessing like a reed switch...or something). works quite well. it was the garage that set up the timing, i will check tonight/tomorrow!
_________________
1985 Mini Mayfare (1275)
1976 Mg Midget 1500

[Finch661]

i have ordered a new dizzy cap&lug, and going back to the points (getting rid of the britpart). I have also ordered a new fuel pump and new rubber fuel hose. If i replace the points, and check the timing (then check the dwell limits), replace the fuel lines (so that anything that has fuel in it is new), and finally get the carbs retuned.... then is there anything else that could cause really bad fuel consumption
_________________
1985 Mini Mayfare (1275)
1976 Mg Midget 1500

[Jim.Walker]

Only the things already mentioned. But the dwell needs sorting BEFORE the timing.
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[Nic Jarman]

A way of "rough timing" to get an electronic ignition setup is to remove the plugs, put one into No 1 lead, connect timing light, make sure plug is toching engine and get a friend to turn the whiz the engine over on the key. Best done in low(ish) light conditions, this will give a reasonable flash to see how far out the timing is. Adjust dizzy and repeat. When the timing looks good, replace plugs etc and strobe in the normal way. Just for future reference put the engine to TDC firing stroke cylinder No 1 and put a mark on the rotor disc and pick up.
_________________
1936 Morris 8 Series 1
1973 MGB roadster
1977 MG Midget 1500
Dax Rush

[Finch661]

right next update. First of all the car is really struggling to start, engine spins over and just doesnt want to fire.... but thats another issue.

I have checked the timing, and its about 10deg BTC as per haynes. i have yet to install the new points, pump and hoses. I tested the vac advance, and dont think its working. Its only about a year old, it makes no difference if the vac pipe is connected. when the engine is reved, the timing remains the same. could it be that the advance plate is seized?

cheers
_________________
1985 Mini Mayfare (1275)
1976 Mg Midget 1500

[MVPeters]

Finch

I think you've got 3 or 4 things going on here - all at once!

First - let's assume you've got fuel in adequate quantity & going to the right places. & that the plugs & wires are all clean & in the right places.
Second - plug the vacuum line at the engine - vac advance is only relevant at cruising altitudes.
Third - from your description, it sounds as though the centrifugal bob-weights are stuck. You should be able to twist the rotor a few degrees & it will spring back. Perhaps something is jamming the base-plate? An over-length screw can do this, eg. While you're inside the distributor, see what's up with the vac advance - sucking on the connection is enough to tell you whether it works or not. Lack of vac advance won't affect starting - an air leak from the open hose will.

Then set the points gap & check the static timing (dwell can come later).
Check all the engine earth connections - especially the battery-engine strap.
Tighten the distributor clamp just enough so that you can still twist the distributor by hand if you need to while you.........

Try starting it.

I hope this helps!!
_________________
Mike - MVPeters at comcast.net
2002 MINI Cooper 'S'

[Nic Jarman]

Mike is right, but on choke leaving the pipe disconected is not too significant. I think the next step is to compession test the engine, poor compression will make it hard to start.
Back to basics; If you have fuel, compression and a spark in the right place the engine will run. Discount what it is not and you are left with what it is.
_________________
1936 Morris 8 Series 1
1973 MGB roadster
1977 MG Midget 1500
Dax Rush

[Finch661]

good morning all. i removed my dizzy and removed the module and vac advance unit. I found that the vac advance unit was working and when connected to the dizzy the advance plates moved. It turned out that on of the module screws was too long and jamming the plates. I put the dizzy back in and then struggled to set up the static timing. Loads of backfires and not a lot of engine running I will try your method nic of setting the static timing and just hope i can get the engine to fire

it also doesnt help that the starter kept jamming
_________________
1985 Mini Mayfare (1275)
1976 Mg Midget 1500

[MVPeters]

I'm guessing that the plug wires are out of order or off by 180 degrees.
Check that #1 cylinder is on compression when you set the static timing.
I expect that the engine is trying to kick the starter motor backwards - once the plugs are firing correctly, you'll probably find that the starter is OK.

You're almost there!
_________________
Mike - MVPeters at comcast.net
2002 MINI Cooper 'S'