MGB MG Idle issues, restart issues solved.

[Eleven22]

This is my first post here, but I have been tackling an issue with my 78MGB that drove me crazy. I finally figured it out and got it running , but let me explain what was occurring just in case it helps one of you in the future.

I could start my car and when it was cold it would run like a champ. If I drove it around 'til it warmed up and stopped somewhere, on restart it would stumble and eventually die. It would also stumble to die when I took it on a long drive and came to a stop. I was having to hold the pedal down to keep it from turning off, just to get it home. I It would cool down again and all was well. I ended up using the shotgun approach and replaced the EGR valve, the run on valve, the gulf valve, filters, sparks, cap , rotor and wire set. still same thing...

I took it to Steel Automotive (British car experts) here in Austin TX and they did the timing , valve adjustments, and looked over the carb. They set all to spec I came to pick it up thinking everything was good. After driving it a good 15-20 min in traffic , it started stumbling. Took it home looked it over, called them up, they suggested the distributor or ignition system had to be off somewhere.

I decided to replace all my vacuum hoses and evap hoses and it seemed to make a diff, I could now drive come to a stop and all seemed well. then i drove it to a friends house and left about 15 min latter. As soon as I started it, it chugged and died. So I did my limp back to my house to start the chalkboard drawings.

I sat thinking about it , and I felt that the evap cannisters had to be the issue. it ran fine as cold, ran fine as hot unless I turned it off waited a few min and tried to restart. Today I took the cans out and rebuilt them with new charcoal, the old filters were destroyed and they were definitely in bad shape. After rebuilding them and driving around til it was hot, I parked it , and sure enough it started and idled! it idles a little low but it doesn't die. and once I start to drive again , all is well when I come to a stop.

Hope this helps someone out there, and thanks for allowing me to join the group!

 

[JPSmit]

thanks for the input - I suspect most of our cars don't have the evap containers any longer, making this even more helpful as most of us wouldn't think of checking there.

 

[Eleven22]

My MGB is almost 100% stock , no changes. haven't lowered it , I still have the smog system on it. But I will say I am definitely pondering making it 5 speed or adding OD to it. the HWYS suck with this and I could use some cruising speed with low RPMs

 

[drooartz]

I have OD on my MGB, and clicking into that high gear is a lovely thing. I've driven one with a 5-speed conversion as well and it was quite nice. Worth doing for sure.

 

[Bob Branson]

Worked at the dealer when your '68 was built, and those cars all seemed to have the same problem, so much so that Leyland sent someone to try to sort it out. I don't recall what the fix was, just that that it was maddening. I've always wondered, since this was right after Leyland bought MG, if they weren't just trying to kill Triumph's competition ;-))