Rupert's MGB Thread

[the Teuton]

British car: Don't buy one without a mechanic on speed dial.

[Rupert]

Mixture good?  I'm not sure how those carbs work but I wonder if you're not getting enough fuel from the accelerator pumps when you hit the go pedal.

I hate to blame the carbs... It's the last place you look on these old things, but, I dunno, everything else seems to check out. And it doesn't happen every time I accelerate, just sometimes. Maybe a float is f-ed up, or maybe the valves are way off. But all of this stuff has been adjusted and checked in the last 50-100 miles, so I dunno. I think it's back to the mechanic, and then we'll see. Maybe the fuel pump is trying to die...

[Rupert]

British car: Don't buy one without a mechanic on speed dial.

[280Z Turbo]

This is the only sensible fix:

[Rupert]

It's British!

This is the only sensible fix:

[bing_oh]

I hate to blame the carbs... It's the last place you look on these old things, but, I dunno, everything else seems to check out. And it doesn't happen every time I accelerate, just sometimes. Maybe a float is f-ed up, or maybe the valves are way off. But all of this stuff has been adjusted and checked in the last 50-100 miles, so I dunno. I think it's back to the mechanic, and then we'll see. Maybe the fuel pump is trying to die...

Bad/leaky floats are not an uncommon problem in cars of this age...the floats are pretty much always replaced when an SU or Stromburg carb is rebuilt professionally, even if there's no sign of leaking. They do eventually wear out, and small leaks can create big problems. Also, it takes a very gentle hand to get the adjustments right. Many times, it's just easier to have them professionally redone instead of doing it yourself. It's actually not even that expensive.

http://www.sucarburetors.com/
http://www.joecurto.com/
http://sucarbs.com/

I fully intend to have the SU's on the Triumph redone by one of these as part of the restoration.

[bing_oh]

It's British!

This is the only sensible fix:

Why, you evil, evil man! I've found your problem...you've insulted your MG! Classic Brit cars have souls and personalities. You must love them to make them work. And, once they find a home, they will not leave.

[Secret Chimp]

This car is starting to sound like an abusive relationship on wheels.

[S204STi]

lol

[Rupert]

This car is starting to sound like an abusive relationship on wheels.

It so very much is. I'm not sure who abuses who, though.

[Rupert]

Why, you evil, evil man! I've found your problem...you've insulted your MG! Classic Brit cars have souls and personalities. You must love them to make them work. And, once they find a home, they will not leave.

I love it when it runs! It should know that by now, ya know? It's like training a dog, I guess, except this dog doesn't want to be trained. x_x

[Rupert]

This morning I had an idea: The coil! It's a new coil, but that doesn't mean it's a good coil. I took it into work to use the better ohmmeter here to test it. This is a Lucas Sports coil, model DLB105. What I found:

Primary resistance is 3.0 ohms out of 3.0 ohms
Secondary resistance is 9.1 kohms out of 8.3 kohms

It's only a little out of spec, but it's only a little problem, so I'm going to replace it with a Pertronix coil (which is better for the Pertronix kit in there already, anyway). I hope this fixes it...

[bing_oh]

I love it when it runs! It should know that by now, ya know? It's like training a dog, I guess, except this dog doesn't want to be trained. x_x

Yes, but Brit cars are designed to run only about half the time! And you're suppose to treat them like a woman...they're just about as moody. Calling her a dog will not get you that return lovin'...

[Rupert]

It's behind her back, so she can't hear me.

[bing_oh]

It's behind her back, so she can't hear me.

Many a man has believed that about a woman, too...

Besides, Brit cars are psychic. We used to call my TR "Christine" after the Stephen King novel. I swear it had a mind of its own.

[Rupert]

Bad/leaky floats are not an uncommon problem in cars of this age...the floats are pretty much always replaced when an SU or Stromburg carb is rebuilt professionally, even if there's no sign of leaking. They do eventually wear out, and small leaks can create big problems. Also, it takes a very gentle hand to get the adjustments right. Many times, it's just easier to have them professionally redone instead of doing it yourself. It's actually not even that expensive.

http://www.sucarburetors.com/
http://www.joecurto.com/
http://sucarbs.com/

I fully intend to have the SU's on the Triumph redone by one of these as part of the restoration.

Yeah, I know about all of those guys. My guy can rebuild them for way less, though, so I'll do that if necessary.

But you know how it is-- do carbs last. If it's not the coil, maybe it's a vacuum leak or an air intake problem. If not that, maybe the valves. If not that, then maybe the carbs.

[Rupert]

Many a man has believed that about a woman, too...

Besides, Brit cars are psychic. We used to call my TR "Christine" after the Stephen King novel. I swear it had a mind of its own.

Yeah, well, I'll tell ya what, if I had a woman that treated me like the B treats me, I woulda broken it off long ago.

[Rupert]

And another thing, those guys over at the MGB forum sure try to help, but sometimes they don't seem to comprehend the question. 0_o

[Secret Chimp]

And another thing, those guys over at the MGB forum sure try to help, but sometimes they don't seem to comprehend the question. 0_o

Miata.net is worse. They start asking you questions about your question that presume you haven't already done what actually led up to your question.

[Rupert]

This guy saw the words "ignition" and "missing," and went right to the whole what-to-check-first spiel. He even mentioned ignition-before-carbs. Come on, I just wanted to know if anyone has a link to the specs of the coil I have (since the data I have is unsubstantiated and I can't find another source).

They don't, BTW. God.

Maybe next time, I'll just leave out the problem I'm trying to solve.

[Rupert]

It's like, ask if anyone has seen a rubber washer gasket for the valve cover bolts cheaper then Moss, because yours leak, and they'll go into why it leaks, what else leaks, throw in jokes about all British cars "marking their territory yuk yuk," why you should check fifteen other things first, why the washer thing isn't your problem, which ones are the best, and never get to where they got them for cheaper than Moss. And this is after you explain why you know it leaks, what else leaks... You get the idea.

[Secret Chimp]

Yeah, that's exactly like Miata.net. For example, I say I've determined my trunk seal is the cause of my leak, first response is "Did you check the tail light and frankenstein bolt gaskets?" I checked your mother's ass, answer a question.

[Rupert]

Here's a new one: I put the new Pertronix coil in there, and the ignition wire won't stay on the coil, because the hole in the coil is too big for the wire. This is so far beyond ridiculous, I'm not even laughing.

This car is like a little, evil devil-child that you keep trying to leave in the woods, but he shows back up at camp every night, looking cold and wet.

Or like the laziest lardass ever, who always finds another way to not have to do anything.

[Rupert]

Fixed it.

What a humbug.

[Eye of the Tiger]

So... it runs?

[Rupert]

Probably. It's too late to test it.

[Rupert]

OK, more clues. I didn't fix it with the new coil and plugs (which I 2/3 suspected), but now I can at least add a symptom (I feel like a stupid and more sociable version of House).

Before,

It runs great, drives OK, until, hesitation/stumbling/missing on acceleration. I drove it around a bit, to try to figure out the problem. It will happen during acceleration only, and not necessarily as soon as I hit the gas. There is sometimes a weird plinky noise coming from what sounds like the driver's side. That's it.

was the problem while driving. Today, I went out for a test drive, but I'm smart enough to let the poor car warm up first. While it was warming up, I played with the throttle a little, and lo! the sound!

It's a plinky clicky clunky noise, and it's definitely coming from the carbs side of the engine, and I think it's coming right from the carbs. Upon lifting the throttle, sometimes, this sound happens. Now, it seems like it could be a backfire, but it's not very loud, and my experience with backfires is that they're really loud. Sort of like a hammer hitting a small nail. I checked the timing (yet again), and it's right on, so long as I remember what each mark means (which I'm about to check). The only other thing I can think of is the valve clearances. I guess it could be a vacuum leak, since those seem to cause every problem known to British cars. Further ideas?

[Rupert]

Two valves were tight, one was a little loose, and now the engine is flooded because I tried to start it without the coil wire attached.

I'll start it later on and get back.

[Rupert]

Nope, that didn't do it.

[S204STi]

So is this noise coming from the motor itself or is there something else rattling around you think?