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 - Problem with idle

I’m having a problem setting the idle, it wants to stay at 2000-2500 RPM. I’ve tried setting the slow-running adjustment screws as shown in fig D-7 on page D-10 in the WSM but I can’t seem to slow it down. What am I doing wrong?

Dave
david kirkpatrick

Moving to the top looking for some advice.

Dave
david kirkpatrick

When idle speed is to high, one of the throttle plates is not closing. If the throttle plates did close, and there was an air leak somewhere else, it would not run for lack of fuel.

Loosen the throttle shaft accordion clamp so the carbs can move independently. Back of the idle screws to close the throttle valves. Be sure there is slack in the throttle cable, and the fast idle cam is not interfering. Play with the idle screws to find the point where the closed throttle plate just begins to move. Give each idle screw 1/2 turn open. Fire it up, and it should run as a reasonable idle speed. If it idles a bit too fast, then back of the idle screws, always turning them equal amount. When you get it right, tighten the shaft clamp, readjust fast idle cam and screw, and check for minimal slack in the throttle cable.

You should be able to shut down the throttle plates enough to completely kill the engine (too slow idle). If it can't be done, then one of the throttle plates is misaligned and is not closing all the way. To properly align a throttle plate, loosen the small screws securing the plate in the shaft. Back off the idle screw, close the throttle plate with your fingers, adjusting position until it touches the throat all the way around to stop all air flow. Then tighten the small screws (and be sure they are secured so they cannot come loose and fall out).
Barney Gaylord

This thread was discussed between 05/10/2013 and 06/10/2013

MG MGA index

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