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Engine Sputters

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edndale

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We have a 1979 MGB that sputters before completely shuts off after turning the ignition switch is turned off. Sometimes, after driving for awhile and we slow down to come to a stop, the engine shuts off, we turn the key and all is well to we come to a slow down/stop again. Any ideas on what to check for?
 
Welcome....please post info about your car and perhaps a picture in the gallery, if you have one:

Anyway,we'll assume you have clean air filters and oil in the carb dampers;

Idle speed too fast?
Timing ("run on" sometimes caused by retarded timing)?
EGR or "gulp" valve stuck or dirty?
Float bowl level set too low? (or dirty fuel filter / low fuel pump pressure)
Vacuum leak?

Also, check this thread as some of the suggestions may be relevant:

https://www.britishcarforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=4&t=000711

[ 03-13-2003: Message edited by: aeronca65t ]</p>
 
Based on the symptoms you decribe, I think I had a similar probem last fall. Mine turned out to be the anti run on valve. The first thing I would check would be the anti-run on valve...the little round cylinder right in front of the charcoal canisters with two wires coming out the top and the hose connected to the cannisters. At least that is how it is on the older B's. I know they went to a double cannister set up on the newer ones, but when the cannister(s) gets old they tend to do funny things to the anti run on valve. It is possible that you just need to blow out the hoses and check the connections on the valve...good luck!

Bruce
 
my midget did that a lot last year. did you check your mixture? its possible your running pretty rich and flooding
 
i asked this before and no one could help me but my anti run on valve isn't hooked up right. there is no hose coming from it going anywhere near my carb or the manifold. there is a spot on the valve but there is no hose and I also don't know where the hose goes to on the manifold or the carb.
 
no...the antistall dashpot is connected to the the cannister on my 74...I'm not sure how the newer ones are set up...I cleaned out the upper pipe to the cannister and the cannister to cure the problem described here...the other pipe from the antistall dashpot goes down to...I forget where, but I didn't mess with that half of the set up to fix my "sputtering problem" as you described...it was in the cannister-valve are some where.

Bruce
 
It could be your timing have you checked it and how close to spec is it
 
There are three hoses attached to the anti-run on valve...one goes to the evaporation canister; one goes to the bracket where the radiator is located and is connected to ... nothing. Both of those hoses are large in diameter. The small dia hose connects to a location on the intake/exhaust manifold between the carb and the engine. There is a hose "nipple" ( for lack of other description) that sticks straight up...on the manifold itself. The small dia hose connects at that location, on mine. When the anti-run on valve is working everything is fine and the engine does not sputter and back-fire. When the valve is bad or connected improperly/ or disconnected...then no matter how well the car is timed or the carb is adjusted... it will backfire, sputter, or "run-on" after the key is off.. If the anti-run on valve goes bad and is left connected... it will run your battery down. Weird; I know but it will do it. When the valve is not working it creates a dead short if the ignition is off. It has happened on two of my Bs.
Cheers, Steve
 
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