Hard starting, but then runs fine

[Guest]

Hi all, I just joined after searching for a good MGB forum.

I have finally purchased a 1973 MGB in fine condition. However, beginning ~2 weeks ago it wouldn't start in the morning - a little squirt of starting fluid and it fired right up. Now it will only start after 5-6 big squirts of strating fluid. It;'s always in the morning. Each time it runs rough, then quits - several sconds after the starting fluid has burn off.

Crazy part is once it's running it runs great. Even parking it for several hours it'll start right up and run fine.

To start I pull out the choke fully, wait for the fuel pump to stop clicking and don't press the accelerator pedal.

It has a new coil, rotor and cap with good spark.

The carba are stock: SU HIF

Any help will be much appreciated.

 

[Bruce74B]

Welcome to the forum...sounds like you have made her into a starting fluid junkie? it only starts with a little bit...

But seirously, it sounds like you might have a moisture problem...either in the gas, for which a can of dry-gas or other such additive out to fix you up...or condensation in your distributor, for which I would recommend a new cap,points and condensor if just a good wiping doesn't help. I am not expert, and always look for a simple answer first, but I bet one or other of the above will help wein her off the morning SF fix ;-)

But then, I am not worth a ^%*( until I've had my morning coffee...

Bruce

 

[Guest]

LOL - I bought a case of starting fluid and the sales guy made a crack about me having a lot of chain saws. I just smiled.

I'll dig down into the distributor, wipe it out and replace the points and condensor. Cross your fingers.

Thanks for the sugestions Bruce.

Kennard

 

[90 XJ-S]

Hey Kennard,

Welcome to the forum, you picked a good one...Someone here is bound to be able to help you with your problem.
I agree with Bruce.. My first thought was a weak spark. Once you fire it up on starter fluid and she gets a little warm she has enough to keep going.
I would check;
distributor as Bruce suggested
coil
coil HT wire
spark plug wires
spark plugs
Battery? believe it or not a old, weak battery will present these symptoms.

Keep at it...one thing is for sure... these LBCs can be fixed. /ubbthreads/images/graemlins/grin.gif

Mike

 

[V8Blazer]

Look for smoke when it finally does crank. It could have a leak that builds up over time when it is sitting making it hard to start, but not fast enough to hurt while running. Ive had 2 head gasket blowouts that started in that manner.

 

[Guest]

I ran a compression test and one of the cylinders is low compared to the rest. A Tbl of oil didn't help so you may be on to something here. I've read about leak down testers and I'm going to either make one or buy one. They sound like the perfect diagnostic tool. Do they work by measuring the pressure differential across an orifice?

 

[V8Blazer]

One low cylinder. You have 2 possibilities.
1. Rings.
2. Head gasket.
Rings are unlikely if your firing great, and the plugs are clean. Slow start, but runs fine is the key phrase. Your symptoms are CLASSIC head gasket, and seeing as it takes literally 20 minutes to remove the head, I say dont waste any more time on diagnosis and replace the head gasket. Of course the possibility is also there that you have a cracked head, but you can cross that bridge when you come to it.