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Carb Question

Rick G

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I need the mechanic's eye for the totally inept guy. I got the BT7 back from the garage and after replacing the fuel pump, it had a miss at low speeds....sort of like only firing on 5 cylinders....just had it tuned about 500 hundred miles ago.......anyway, it is not the easiest to get started in the cold, so I spray some starter fluid in the carbs and it usually does the trick. Not this time..no way, no how is this baby going to turn over. As I was mking the 10th trip under the hood to try and figure this out, I notice that one of the brass hexigon nuts at the top of the bell on the carbs was completely loose (you could see in the top)and the other was very loose. Could this be the source of my failure to start? I tightened them back up, by I need to charge the battery to see if it works. Any help would be appreciated.
 
Unfortunately, the brass nuts you mention are just the caps of the dashpot pistons, and won't make any difference in starting, at all. I trust you filled them up with oil before you tightened them back down.
Now, as to you no start problem, is the engine turning over at all? Your post was unclear if it just wasn't firing, or not even cranking.
If it's not spinning over, check the usual suspects, battery terminals, connections at the starter, etc.
If it is cranking, check for spark at the plugs, for the first thing. It's possible that after setting for awhile, some corrosion has built up on the contacts of the points, preventing spark from occuring.
Hope this helps.
Jeff
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Rick G:
I got the BT7 back from the garage and after replacing the fuel pump, it had a miss at low speeds....sort of like only firing on 5 cylinders....just had it tuned about 500 hundred miles ago.......anyway, it is not the easiest to get started in the cold, so I spray some starter fluid in the carbs and it usually does the trick. <hr></blockquote>
Well Rick, sounds like you have more than one problem. Charge the battery back up. Check to make sure the choke is working and that you have gasoline to the carbs (stuck float needle?). (You shouldn't ever have to spray starting fluid in a Healey). Then check for spark at the plugs, as was suggested. Good Luck.

driving.gif
 
While we're on the subject of starting problems, anyone got any ideas about the most likely cause of mine before I dive under the bonnet?

My BN1 is fitted with a modern lightweight starter and electronic ignition. The car turns over very strongly but I'm having perhaps twenty to thirty attempts over a period of 10=15 minutes before it fires. Once it catches it runs OK and it restarts fairly easily once it has started the once.
 
Most Healey's start right away. If they don't it's usually because they are flooded, or they aren't getting any gas. Flooding is a problem on first start up due to a carb needle sticking allowing too much fuel into the intake. This is common when new fuel pumps are added without a regulator. You might want to check the fuel pressure and when it won't start right away, check the carb bowls, you may find a float submerged.
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by catfood:
While we're on the subject of starting problems, anyone got any ideas about the most likely cause of mine before I dive under the bonnet?

My BN1 is fitted with a modern lightweight starter and electronic ignition. The car turns over very strongly but I'm having perhaps twenty to thirty attempts over a period of 10=15 minutes before it fires. Once it catches it runs OK and it restarts fairly easily once it has started the once.
<hr></blockquote>

Sounds like you're not getting any fuel into the cylinders. I'd start by making sure that the chokes are fully functioning.

As a test, you could dribble a small amount of fuel into the carb throats (under a condition when you expect hard starting) and see if it fires right off.
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by catfood:

My BN1 is fitted with a modern lightweight starter and electronic ignition. The car turns over very strongly but I'm having perhaps twenty to thirty attempts over a period of 10=15 minutes before it fires.
<hr></blockquote>

Steve:

I would check fuel delivery first too. Then:

I have seen this problem with certain American GM products and it generally turned out to be a faulty "ignition module" (the device that replaces the points under the cap in your car).
Try cold starting and check the distance the spark will jump. Obviously, use insulated pliers or similar (especially if you have a weak heart!). The spark should jump at least 15 mm to a good ground. After getting the car started, shut it off and try again....see if it's better. If it's changed significantly, the module is suspect.
Also, be sure you aren't running a ballast resistor AND ballasted coil. If you run both, you'll get a weak starting spark.
Finally, just in case spark is "leaking off" somewhere: find a dark parking spot in the evening and start the car. Open the hood while the car is idling and spray a light mist of water over the engine (a plant sprayer works well). If you see any sparks jumping, you may have weak insulation in secondary wires, cap, coil, etc.
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by catfood:
The car turns over very strongly but I'm having perhaps twenty to thirty attempts over a period of 10=15 minutes before it fires. Once it catches it runs OK and it restarts fairly easily once it has started the once.<hr></blockquote>
Steve,
Hot or cold starting or both? Depending on which, there could be opposite problems.
D
 
The problem is with cold starting. The engine doesn't catch at all for ages, then will fire a couple of times and then start up. It doesn't seem to be a problem once it's been running for a minute or so, it fires fairly easy then even when not warmed up.
 
Steve,
As Randy said above.
"Sounds like you're not getting any fuel into the cylinders. I'd start by making sure that the chokes are fully functioning."

Since it is only a cold problem, you can rule out hot ignition components & flooding. When you pull the choke knob all of the way out you should be able to see the jets in the carbs move lower. If not the linkage needs to be adjusted or repaired.
D
 
Thanks for the advice guys, I'll try and make time this weekend to check out your suggestions, starting with the choke...
 
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