MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - Won't start-fuel problem help

Car was cutting out at times. Assumed rust in the bowls that has happened before. Cleaned them out. Filter had rust so I changed it out. Blead the fuel line until it was clear. Removed carbs and cleaned bowls and rest of carb. Now have full fuel bowls but car will not start. Althought I did a tune up I am getting spark but plugs are dry after cranking and choking. fuel pump is pumping fine and as mentioned, bowls full. Air blown up through over flow pipes put fuel into the carb body where the needle enters. Thought maybe I have the distributor 180 off but switching the wires did not help and I keep comming back to dry plugs means fuel. Suggestions please.
Thanks,
Randy
RAP Palsgrove

It is easy to verify no fuel by spraying some combustible like carb or brake cleaner into the carbs. If it runs while spraying and dies when you quit then there is no fuel. If that does not start the car re check what ever else you touched first.
R J Brown

I do exactly the same as R.J. to always verify if the problem is fuel or ignition. If you don't have carb cleaner I have even Dripped fuel into the throats of the carbs whilst cranking the engine. This will always start the engine if fuel loss is the problem.
Bob (robert) yes Y8 is toast again :)

If I place the plugs for firing order 3, 4, 2, 1 it turns but not smoothly. Sort of hits a thud and turn a couple and thud. If I spray in starting fluid it does fire and runs 15 or so seconds and revs during that time. If I have the firing order 1, 3, 4, 2 it spinns freely and smoothly but does not start even after fluid is added. Help!
Randy
RAP Palsgrove

Have you had the distributor out? It sound very much like its firing at completely the wrong time.
Malcolm Asquith

I have not had the distributor out but have removed the wires during the tune up and may have them out of sink. Although I think the MGA will run, enen roughly, with things out of sink. I have traded off the wires assuming I have the distiburtor out of sink but did not seem to make a difference except it turned freely, just did not fire.
Thanks,
Randy
RAP Palsgrove

1 3 4 2 is the correct order!
Art

OK so what's next? Did the archives and did what was suggested. Fuel seems to be there at the carbs but not at the plugs. Pump works fine, bowls full, blow in the overflows and fuel comes into the carbs. What to check next?
Randy
RAP Palsgrove

Randy, it seems you have a blockage between the bowl and the jet. Sorry to state the obvious. But having said that, it must also be in both carbs or it would at least cough. So go dismantle!
















Art

Sounds to me as if the spark problems need sorted first. Pull #1 plug and crank engine to verify that the rotor points to #1 when compression comes out of the #1 hole. Watch the direction that the rotor turns and install wires 1 3 4 2. If you use a screw in wire type cap the order can be confusing. You must look at the inside of the cap to figure out the order.
Once you have the ignition set right the engine will run on carb spray if the fuel is not working.
The chance of both carbs plugging and quitting at the same time is slim.
R J Brown

The turn - thud syndrome is because the engine is trying to fire on the wrong cylinder. It suggests that you have at least a weak mixture getting through, because the engine is firing albeit at the wrong point in the cycle.

What state are the seals between the float bowls and the carbs. If you have had a serious rust problem, check the banjo bolts that hold the float chambers to the carbs, the hole is relatively small and could be blocked in both cases. If the seals are dodgy, it will suck air in too, which will not help matters either.

It does sound as if a "from scratch" setup is the best way to resolve the problem (I did this with Allan on his car a couple of weeks ago, and the car then ran much better than before). Start with the distributor setup, then take off the dashpots and remove the pistons to do a basic set up of the carbs (see archives), checking that all seals are good and holes are clear of blockages. Going back to first principles is more time consuming, but compared to fishing blind, it's always a timesaver.

dominic clancy

Have removed the carbs and checked everything and all seems well. There was also fuel laying in the intake maifold so I normally would assume it is not a fuel problem but the plugs are still not showing any moisture???

I did install electronic ignition during the tune up. I can get the car to fire if I play with the plug wire locations. It spins freely with 1342, but will not start which brings up my next question. When discussing firing order I generally see the 1 spark plug wire is 2'clock on the distributor looking down on it, the 3 is 10'clock, etc. I am assuming the 12'clock is where the coil wire come out because my distributor's coil wire is not straight up but to the right in what I would consider 2'clock. I also rotated the engine until the #1 piston is at top and the rotor is pointing at either 4 or 10'clock. Can someone bring this together for me?
Thanks,
Randy
RAP Palsgrove

Randy you must get the number 1 plug to "fire" when the number 1 piston is on compression stroke so as you quite rightly observe when the number 1 piston is at the top of its stroke then the dizzy rotor arm is pointing at either 1 or 4 but you must decide which. With number 1 on compression then the dissy rotor MUST point at number 1.
Your firing order would seem to be correct as it runs anti clockwise around the dissy.
Bob (robert) yes Y8 is toast again :)

If you have played with the distributor, then it's more than likely an ignition issue not a carb issue.

The fastest way to sort it out is to go back to basics, and set up carbs and timing again from scratch. Don't skip any steps on the way, and the car will then start and run just fine. Random fiddling will take more time and get you nowhere.
dominic clancy

Carbs were pulled for the second time and there is no blockage anywhere. The rubber grommet/washers on the bowl to carb I just replaced because one was leaking. These carbs are clean, and cleaned again. Fuel puts out plenty of fuel, again checking that the gas is clear coming in.

Not sure if the #1 was on compression or return but either way, the rotor does not point at #1 in either TDC. Again, am I to assume the location of the distributor would have the coil wire pointing at the 2'clock position which mine does. So that said, it seems my dizzy may be off 180. I need to know if I put the 1 piston in compression TDC do I need to pull the dizzy and just line it up that the rotor points to 2'clock assuming the coil wire is the 12'clock and not that the distributor should not be pointing directly up as determined by the coil connection. I am using an original style distributor.
Thanks,
Randy
RAP Palsgrove

I'm not an expert Randy, but it sounds to me like your timing is way off, but not by 180 degrees. You said the wires exit your distributor at the 2 o'clock position. I just had a look at my engine and it's more like the 3 o'clock position where the wires exit the distributor.

I think you should heed the previous suggestions and start back at the basics. The rotor MUST be pointing at #1 when it's at top of it's compression stroke.
Andy Bounsall

You will have to get #1 at TDC on its compression stroke and then make sure that the distributor rotor is set at the correct plug wire. The factory manual does give secific locations for where the rotor should be, but if someone ever had the distrubutor drive gear out it may not have been located per the manual when reinstalled.
John H

Just a hint:

The valves will both be closed when that cylinder is firing.

Hope that gets you goin'!
Tom

This thread was discussed between 18/06/2007 and 21/06/2007

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.