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79 Won't Start

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David Palmer

Freshman Member
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I have a 1979 MGB with a Weber 32/36 DGEV carburetor, a Lucas 45DE distributor, and an 18V883 model engine. The trouble started a few months ago after I had the gas tank filled, and ran the car for a few minutes. It ran just like it always had, then suddenly cut out on me, and I could not get it to restart. I recently removed, cleaned and reinstalled both the carburetor and the distributor, reset the timing, and am still unable to get the car to start. The starter will crank the engine, but it will not fire. I am getting a current to the distributor cap (which I discovered the hard way), but I do not appear to be getting a spark on any of the spark plugs. The distributor cap appears to be clean, and all of the connections seem to be OK. Is there something simple I may be overlooking, or do I need to look into replacing the distributor or something even more serious?

David
 
First: you drained the tank, right? (you didn't say, but I'll assume you did)

Many of these LBCs are fussy about fouled plugs. Even if they look good, replace the plugs.....they can be shorted due to fouling deep inside the center cone.....I've found that no amount of cleaning truly "fixes" a badly fouled plug.

I think I understand what you said about finding voltage to the coil...but just in case.....have someone else crank the engine over while the center wire (from the coil to the distributor cap) is removed from the distributor cap. Hold it about 1/4" from any metal part of the car and be sure it will jump across that gap. If it won't jump, it's probably your points or ignition module (a fair number of these cars are converted to electronic igntion). If it does jump(you might have already done this), them it pretty much has to be the cap and/or rotor. Spark plugs wire could be bad too, but they usually don't all go at once.
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by aeronca65t:
<snip> Hold it about 1/4" from any metal part of the car and be sure it will jump across that gap. <snip><hr></blockquote>

Hold it using a very very well insulated screwdriver (and rubber gloves wouldn't hurt either). Otherwise, you could get a bit of a shocking surprise (me speaks from experience
crazy.gif
) And for goodness sakes, use one hand and make sure your other hand isn't touching anything on the car...if you should take a jolt, its best not to allow the current to pass through the heart - hearts don't like that much. Not really that big a deal, and I'm not trying to scare you, just be careful!

Basil

[ 06-18-2002: Message edited by: Basil ]

[ 06-18-2002: Message edited by: Basil ]</p>
 
It could be the Ignition module itself,The Lucas electronic ignition in the car is problematic. I had the same thing happen to my "77 Midget. I replaced the lucas system with the one by Petronix
(around $100 at Moss or Victoria British)It is self-contained and fits in the distributor with no external amplifier and worked for me like a charm!
Good Luck
Joe V
 
Hi David;
I had exactly the same problem with my 1971 MGB. If I understand you correctly, you have juice to the distributor but you don't have any spark from the plugs.
Basil proposed a good suggestion on how to test to see if you have spark from the plugs. What I did as I fear shocking myself is to attach a jumper cable from the spark plug to a grounded piece on the car (ensure that it is the same jumper lead, either black to black or red to red). This way when you turn the ignition over you can see if there is spark without trying to juggle.
So...what you are waiting for...when I proposed the same problem when I had it to fellow MG enthusiasts I received many helpful responses. I was told to replace the rotor and distributor cap as cracks in these will conduct electricity and bypass the circuit you want to make.
Before you replace these things you might want to (and probably already have) watch the gap of the distributor open and close as the engine turns (i.e. with the distributor cap off, of course) and ensure that you have the correct gap between the points.
What fixed mine (and I apologise for the suspense with a pathetic ending) was a distributor replacement. Unfortunately, this problem was intermittent which was frustrating as I changed numerous things but didn't know whether what I had done had solved the problem. In addition, I was in the middle of exams when the car died the last time and I had to have it towed to the shop not allowing me to search further for a cure. They just replaced the entire distributor ( not the most economic of solutions)
Anyway, I hope that helps,
Matt
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I've found the easiest way to tell if a plug is getting juice is to just hook up a timing light to the wire. It might not confirm a "hot" spark but you won't get a shock. In this case where the car won't start, I'd suspect the cap or rotor (as was stated before).

John C
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Matt:
Hi David;
Basil proposed a good suggestion on how to test to see if you have spark from the plugs. <snip> <hr></blockquote>

Actually it was aeronca who suggested how to check the spark - I just added a caution not to zap himself - we wouldn't want to loose him before he makes "Senior Member" here
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Basil
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[ 06-18-2002: Message edited by: Basil ]</p>
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by coldplugs:
I've found the easiest way to tell if a plug is getting juice is to just hook up a timing light to the wire. It might not confirm a "hot" spark but you won't get a shock. In this case where the car won't start, I'd suspect the cap or rotor (as was stated before).

John C<hr></blockquote>

Now THAT is a good idea - in fact, I just did that recently when I was having trouble with my Nissan Pick up truck. I used one of those induction timing light that you just put the clamp around the wire.

[ 06-18-2002: Message edited by: Basil ]</p>
 
Ok... I replaced the rotor and the distributor cap last night, and I've gotten farther than I have in the past. The engine started to cough a couple of times, belched out some white smoke (I haven't been able to start the engine since early April
frown.gif
), but I couldn't get it to fire up and run. Could I need to reset the timing again?

David
 
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by David Palmer:
Ok... I replaced the rotor and the distributor cap last night, and I've gotten farther than I have in the past. The engine started to cough a couple of times, belched out some white smoke (I haven't been able to start the engine since early April
frown.gif
), but I couldn't get it to fire up and run. Could I need to reset the timing again?

David<hr></blockquote>


White smoke? What does your oil look like. Also, what does your coolant look like? Take all your spark plugs out and crank it a few times. See if any water comes out of the holes.

Basil
 
Thanks to everyone who offered tips and assistance. It turns out that I somehow managed to turn the distributor 180 degrees, but with it newly installed and with a replacement rotor, the engine fired right up.
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As for the smoke, it does not seem to be an issue any longer, as I have not seen any since the car started running normally.

Now, however, I have a new problem.
frown.gif
The car starts running normally, but if I let it run for a short time, the throttle on the carb seems to get stuck, and the engine will redline whenever the clutch is in, and the engine is not engaged. Not a big problem when I'm actually driving (gives me a "cruise control" of sorts), but I'm sure this is not good for the engine or the carb. I did recently reassemble the carb according to my Haynes manual specifications, but I don't know what could be causing the problem. Any suggestions?

David
 
Good work on getting the car running David. I bet that you repaired a lot of stuff that needed repairing before you actually found the cause. So your time was not wasted.
As for your idling problem...just be sure that you put the carbs back together properly. Particularly the throttle linkages that sit just between that carbs on the engine side.
When I originally got my car started I had reassembled the carbs incorrectly so that one of the carbs was on full throttle and the other was sputtering. This resulted in a great fire show...a fire ball was expelled from the carb that was on full throttle every thirty seconds. Fortunately this was easily repaired.
Good luck,
Matt
 
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