Mystery Diagnosis Time

Newbe back!
Patient: 1978 MGB

Chief Complaint: Sonofabiscuit Wont Start

History: Two weeks ago the car wouldn't start. I tried jump starting it and that didn't work . I took the battery in to charge as I am suspecting the alternator isn't working. Got back the battery and placed it in and upon turning the key I can hear the fuel pump working, and I can see the fuel gauge go up so I know there is enough fuel . I turned the key and it sounds like its struggling to turn over but won't.
So I sprayed some of the starting fluid in the carb and the engine fires up and dies within seconds.

Possible Diagnosis:
1-Dead Alternator
2-Starter
3- ???
4- ????

Worse case scenario I get it towed to the mechanic, which I am trying to avoid.
Once I get it started I have a new alternator, starter, spark plugs, distributor caps that will be changed, but just need to get it to the mechanic.

Any suggestions as to how to get it started or what it might be.

thanks

ajay

Turn over means cranking on the starter. So 'struggling to turn over' is inconsistent with 'runs with starting fluid'.
Firing means it runs.

Stopping after firing means no fuel or no air or no spark. If it fires on starter fluid then dies it means no fuel or bad fuel.

Check the floats, fuel filter, lines and make sure there is fuel to combustion chambers.

The fact that it runs on starting fluid and then dies suggests that it is not getting fuel. Stuck float?

If your car starts with the help of starter fluid, I'd bet you have a fuel delivery problem.
Check and see if your getting fuel to the carburettors. If not, it might be your fuel filter.
I believe the later models have an emergency fuel cut off valve that can be re-set. Check to see if this is the problem.
I don't know where it's located but others with a later model car will probably post.

If the fuel pump is running - it isn't the inertia switch! Like the others have said - check the carb(s), especially float valves.

Another thought - if the fuel pump ticking constantly? If so, it may be drawing air into the pump, a pump valve may be stuck, or the pump may need priming (some do, some don't). To check if it is working, remove the fuel line at the carbs, put the end in a large jar (or similar) and turn on the key - if no fuel appears - you have found the problem!

Hey guys,

Once again, thanks for the quick reply... so it seems to be the general consensus that its the fuel...so I shall look into that

1- Will take off fuel delivery hose and see if fuel is making it to the carburetor.

2-

How old is fuel?

Stale fuels stinks.

I doubt it is that.

When was car last running.

You're about to have an unpleasant reminder not to use styrofoam to hold gasoline.

It sounds a bit like fuel because of the starter fluid but it could be weak spark - sufficient to ignite the starter fluid but not enough to ignite gasoline. It could also be your water choke stuck open flooding the system. I assume you still have the ZS? Basil

Looks like a Weber to me.

whoooooooooaaa! Guys!

Before you start ripping into your carbs and your fuel system lets look at a few other things. Ripping into the carbs and fuel related components could cause so many problems, ON TOP OF existing problems.

The car could have fired on the starting fluid if it had a weak dead battery and was not turning fast enough. of course, we need to determine these things first.

Ajay, now, 1. have you actually driven this car? (I want to determine if the fuel is good.)

2. When you turn the key, does the engine "spin" fast? In other words, it is "turning over" but not starting? (If it spins fast, your battery is good.)

3. When you put in the starting fluid, and it started right up, How long did it run?

4. How much gas came out of your hose there before it melted the styrofoam cup? hahahaha Did a lot of gas pump out? or none at all?

5. How fast is your fuel pump ticking? Does it sound like its going to the races, or just kinda taking its time (trying to determine if there's gas)

By answering some of these simple questions, we can determine whether you have a battery/alternator issue or a fuel ignition related issue.

Sometimes, people that are new to trying to diagnose car problems mistake the two. If we can rule out any fuel problems, then we can figure out if you have a battery or alternator problem.

Two weeks ago when the car died, had you been driving it regulary up to that oint? and for how long? were there any issues before it died?

B

6.

I have seen batteries read 12 volts but still not start the car, Two problems could be bad cell in battery, or one of the terminal posts have fail. Take the battery to an auto parts store, There should be one in Belize...? Have the put a load test on the battery.

Hey Guys
Once again thanks for the prompt reply and support...so this is where we stand right now:

as per Brian's question:

OK, I think that we have ruled out the battery, the alternator, the fuel pump, and the carbs, with the exception of the choke.

What I'm worried about is the fuel. If you have crappy fuel in your car, it will do JUST THAT, start then die.

What are the qualities of the fuel there in Belize? Could you have bad fuel\? Could it have sat for a long time? Fuel will go bad after a couple months. If its sat in the gas station for a long time, then in your tank for months, it could be old.

I don't have much experience with THAT particular weber carb. But, on this one, I am definitely leaning towards a bad float pin/needle, or bad fuel, or bad choke

Do you have an aftermarket fuel pump? one that might pump at a higher pressure? This will cause the needle to wear after time. But, sometimes they wear out with just normal usage.


How's your work going there in Belize? I loved it there when we went, I would have like to stay longer. Beautiful country and beautiful oceans too.

B

Hey Brian

How can I tell if it is a bad float pin/needle?

bad fuel?

bad choke?

And will adding say 5 more gallons of "fresh" fuel to the tank help withthe old fuel issue?

If only a quarter cup in 5 seconds, I'm wondering if it's a clogged filter or the pump. I would remove the filter and try it again. You may see much more fuel velocity and that would tip youoff to the filter.

Fly me there and I'll personally fix it! Belize!! :) Follow the outlines the other guys have given. I recently had fuel starvation due to a tank with rust/ rust clogged the fuel filter under the hood but there was another one next to the updated transformer looking pump.
Otherwise tell us poor souls in the US how life is down there!! I had a friend just visit and she said she did not want to leave!!
Brya

Probably just a blocked carb jet.

If it was a stuck choke, it would not start and then die.

You can try, with a helper....

remove air filter.
have helper in car and floor gas pedal
squirt some ether in carb to get it going.
choke carb completely with hand to try and draw crap out of jet.

The idea is get revs up with ether, then strangle carb, as engine revs die down half way, unstrangle it hopefully it will rev up again, then strangle it again and so on for a few times.

Make sure helper is not an idiot, and if carb clears he has the sense to moderate revs.

If it fires and then dies, could it be the coil? Do the later models use a resistor and bypass?

Does it fire with the starter engaged and then die as soon as you release the key?

Why does the cooling fan run when the car is cold and not running? Sorry, had to ask.

I recently had a similar problem. My weber bowl would fill and then i would literally run out of gas when the bowl emptied. If I were you I would check to make sure all of your fuel hose clamps are good and snug, you maybe sucking some air. Change your fuel filter. See if that helps. If not and you still have crummy fuel delivery change fuel pump. Take a look in your weber carb at the bowl. If it is coated in red sandy clay like substance it is rust coming from your tank. My issue went away when I did the following:

Made sure hose clamps were tight and fuel delivery was good.
Changed fuel filter
replaced float valve and cleaned out jets (primary jet was 30% plugged) Even a novice can take the top off of their weber and do an inspection/general cleaning without screwing too much up. (buy a weber rebuild kit, they are cheap)
Added Seafoam to my gas tank. (thats not the stuff you find down at the beach in Belize, its in a can at the auto parts store)
All of this seemed to fix my issue. It was probably the float valve or other brass jets I replaced/or cleaned. Good luck.

One other thing is water in the gas or in the float bowl.

Hey guys,

Bryan - if i could afford it I would fly the lot of you down and have you bring parts with you...everything outside the city is amazing...

Dan - enclosed is a pic of the fuel filter...it doesn't appear to be an impurities but I shall disassemble it and clean out the filter to see if that makes a difference

Morris - i think the cooling fan is either running cause the wire for the thermostat is fallen off OR i think it normally runs when i start the car..

also I check then carb and it seems pretty clean

ajay

the carb

Looking at the choke plates (very top of the weber) on the carburetor they are not closed all the way. They should be of cold start up. Stupid question did you push the accelerator all the way down to the floor and release..? This should set the plates closed, if not check to see if the (3) screws are tight on the choke assembly. BTW do you have water or electric choke...?

I think everyone is right that it's a fuel delivery problem. Test the pump pressure and volume. You may have a weak pump. You'll hear it clicking but it may not be able to deliver enough fuel to keep it running thus the enigne dieing after a couple of minutes. It simply runs out of fuel in the carb. I don't have my book with me to look up the pressure and volume but it's simple to do. Disconnect the line from the carb and and attach a pressure gage. Many valume gages serve as a presure gage too. I think it's supposed to be 3 lbs. For the volume test. get a GLASS jar and a measuring cup. Have someone hold the line on the jar and turn the key to ignition NOT STARTING THE ENIGNE, for a specific time. This is the part I'm fuzzy on how long and how much fuel should be delivered.

Progress Notes:

Lets start from the rear

1-gas tank - no leaks, and there is enough "fresh" gas in there as I just added another 2 gallons, so we can rule out No/Bad Gas

2-fuel pump - it seems to be working fine as it "clicks" rapidly and then eases off

3- fuel filter - just installed a brand new one and it filled up pretty fast when i turned the key/the pump seems to be doing its job

4- battery - the battery was just charged so its not that...the alternator will have to be checked but if im not wrong, a charged battery with a bad alternator should still start

The car starts and i manage to get one or two stuttering revs before it dies..

on a side note, the key is starting to get stuck and requires some force to get it out...afraid its gonna snap off

Will attemp to change the spark plugs tomorrow...any suggestions or words of caution

Are these stuttering starts still only with ether?

It is still looking like a blocked jet or little or no fuel in bowl.

If the pump is clicking (like more than one or two clicks) every time you turn the key to start it, there is a problem with the pump OR your fuel is draining out somewhere between times you have the ignition in the "on" position.

I had a heck of a time getting my car to start after an extended "down" time (Weber) and ended up servicing the carb (des-assembled, cleaned, replaced "perishable" items, etc.). After that it was okey-dokey.

But yours has been down only a little while...

Have you tried disconnecting the alternator? Since it is "bad" already you don't have to worry about frying it.

AJ, I just went through this similar issue. Even the old fuel filter looks exactly like mine did. I bet your weber is plugged up somewhere plus you probably have rust in your tank. Salt air by the coast in Belize maybe. I took off the fuel line at the carb and started the pump. With the gas going in a bucket I ran it through a paper face mask you would buy at any hardware store. I was able to see right away that it had tiny rust particles in it. This builds up in your weber and will over time cause problems. I would put my money on your carb as your problem. You should buy a rebuild kit and just take the time to do it. At least undo those 4 bolts on your weber and take the plate off the top of the carb so you can see the bowls and the float. There are two little brass jets at the bottom of the bowl. Unscrew them and make sure they arent plugged. Do a general cleanup in there.

vent the fuel tank, back off the gas cap to the first notch.

Hey Barrie,

Not sure about the 4 screws so I enclosed a pic with the red arrows pointing to what I think are the 4 screws you talking about. Also what does "bowl and floats" look like?

I also uncapped two bolts and little fuel leaked out...the bolts are indicated with white arrows...the one underneath had a little metal mesh that was clear of debris.

As for rebuilding it....Im gonna have to order a kit and have it shipped here as I doubt anyone sells rebulding kits here. BY any chance does anyone know how I can tell what kind of weber i have...i believe its a 32/36 but not sure what kind.

Next week I might have to break down and take it to the mechanic if this continues.

Thanks

Ajay

Good information for different Webers with parts explosion diagrams, tuning etc can be found here: http://www.redlineweber.com/html/Tech/Table_of_contents.htm

AJ, I got my rebuild kit from webersdirect.com. It wasnt expensive at all. Unscrew those 4 bolts you have arrowed. That filter housing will come off. After that there will be several screws in the top of the carb. Take off all of those out and take a look inside. I bet it is a red sandy color down in the bowl. clean it out, take out the little brass screws at the bottom of the bowl, run something through them to clean them out. Your rebuild kit will come with a float valve, gaskets and whats called an eccelerator pump, look these up in the weber diagram. They are not that hard to replace. I am NO mechanic by any means. I just worked at this until I had the carb clean and the jets ect cleaned out so fuel can flow through them. After all youve said this is almost certainly your problem. If you think the carb rebuild will be a problem for you, buy the kit and have the mechanic do it for you. Buena suerte.

This could well be a faulty ignition switch. In '78 they used a 6 volt coil that had a bypass wire running from the starter solinoid to the coil. If it starts up and runs only when the key is turned to the start position, the problem could be the switch which will drop down to giving 6 volts when the key is released and returns to the run position. This, and the fact that the key is getting harder to remove, seems like an unlikely coincidence. RAY

How bout a ballast resistor? The resistor is in line only when not cranking and is bypassed while cranking. If the car only "runs" when cranking.....

I had to do the unthinkable....get a mechanic...
so after trying and trying I realized the carburetor had defeated me (Damn you Weber and your dictionary cousin Webster!) On the plus side I found a mechanic around the corner who makes house calls...so get this, he comes and does a patchwork job to get the car started...the next day i drive it to the shop at which point i had a "OH F*&K" moment as i forgot my brakes werent working...good thing Belizean pedestrians can move out of the way fast :)
so it turns out the following were the problem

1. dirty carburetor
2. faulty wiring (had to short it to get it working as u can see by the enclosed pic)
3. something in the ignition that made the key get stuck

all in all he fixed all of it and got it stop shaking so much when idling... now this is where the wow factor is...house call plus repairing all of the above and the leaking brake line $60 US (which included the tip)

And, of course, it wouldn't be an MG if another problem didnt make itself known...the steering is extremely rigid..but at least its working now...

Once again, thanks for helping me out with this issue...

Sure to be back..

ajay