car wont start

i need help.

I bought a 1976 MGB roadster in December. The car was 75% complete but not running. The zenith stromberg carb was off, so i put it back on, and got it running pretty quickly (albeit a bit lumpy). I had to replace the clutch master cylinder, other than that it was small things. I had the car ready to go, gassed the tank and it died. I did put in an additive to clean out the system.

so i emptied out the tank (gas was orange) cleaned out the carb ,replaced the jet changed the diaphram, replaced all filter but again nothing. In doing all this i lost the timing, as the distributor was loose but i got that back (more on that in a minute)

i had an issue with fuel shooting out of the carb overflow but i put that down to a stuck float. Fixed that, but it still wont go, the previous owner tookoff the auto water choke and i dont see a manual one on there.

when i was setting up the timing i noticed that at tdc the cap inside the distributor is pointing in the right position as the manual says but the lead is #4. Ive not changed anything since it was running so i really dont understand that at all.

i tried starter fluid but it didnt even try and start, also changed the fuel pump as the pressure looked low, and put in a regulator.

im about lost, only thing ive not tried is the needle jet, just got the tool for that from Bhive so i may try that.


any ideas would be welcome, and if anyone knows an MG mechanic in Houston let me know

Graeme.

To eliminate ignition problems run through the ignition testing link in my signature

Graeme,

Welcome to our world. Isn't it fun? It sounds like you know what you're doing so just keep at it, you'll eventually find the problem. Perhaps someone here may be of help:

http://www.houstonmgcc.com/

Also, a member here is David Terry, aka Beedapox, who's in the area:

http://www.mgexperience.net/member/Beedapox


Check that the little graphite button up inside the center of the distributor cap hasn't been damaged; it's easily broken putting on and removing the cap. It provides current path to your coil and stranded me for a time a while back.

Good Luck with it...

Thanks, I have a spark at the plug, so now im thinking carb as it did not fire with starter fluid, I was just thrown last night when I noticed the position of the rotor arm when no 1 pot was at tdc, all the leads are 180 degrees out yet the rotor is in the right place, and it did run like it.....baffling!

Im just starting to remember all these old things, last car I had with points was a 1976 ford capri, and that was, in the 80's

thanks for the replies, and thanks Roger in CA, i lost your email.

I got it running today, for some reason i decided to change out the new condensor, and it started....with some difficulty but still it went and we drove it around the neighbourghood. Its seemd to be missing though, and it must be running rich as the plugs sooted up bad.

The timing has me baffled tho, it seems to be set up backwards, when the rotor arm is at 8 oclock the plug lead is number 4 pot, it seems to have been set up as #4 being #1

i changed it around as it is in the book (#1 at tdc)etc and when i turned over the engine, fuel vapours came out of a little hole in the carb, almost like a backfire!

Any ideas anyone?

Another problem seems to be the alternator, it was draining the battery overnight which i figured to be the diodes so i replace it, but when i connected up with the engine running it almost stalled, one for next weekend i guess!

Hi,

One possibility for the funny timing is that the PO installed the cam or the dizzy, 180 deg out. The manuals are very confusing about this, as the timing marks on the cam and crank need to be adjacent, WHEN #4 IS AT COMPRESSION, not #1 as is usual. Once the cam / crank have been aligned the engine needs to be turned one full turn, to bring #1 to TDC on compression, to set up the dizzy and ign timing.

Herb

Thanks Herb, that seems to make sense. Will it be ok left like it is?

What about setting up the timing if it is left as it is, do i take treat #4 as #1?

Hi Graeme,

Leaving the timing as it is will work OK, just will be confusing, as you've found out.

Another cause has just come to mind, the drive dog on the dizzy may have been installed 180deg out. Mine had this and I could figure out why the dizzy setup instructions gave funny orientations of the rotor.
Also the dizzy drive shaft may be incorrectly aligned with the cam.

Attached is a diagram showing dizzy drive dog alignment.

Herb

Thanks Herb,

my first thought was that the dizzy was 180 out,i have a spare one so i can look at your picture and understand it.

The car is hard to start, so i am just about to pick up fresh plugs points and condenser to see what happens, it sounds like it is missing, and also smells like its runs rich, that points to the timing i suppose, and also a bit of a top end rattle, could that be valves, again i suppose could be timing.

I have a strobe light so i guess its time to use it!

Graeme.

Try taking all plugs but No.1 out, then turn the engine over by hand. You will feel the increased resistance as No.1 comes to it's firing stroke.

Check where the rotor is pointing and put the No.1 plug lead in the cap where the rotor is pointing. Fit 3, 4 & 2 anticlockwise in the other holes.

That should get you started regardless of the orientation of the distributor drive.

Thanks Owen,

i actually did that, #4was in compression, went anti clockwise 4 2 1 3, when i looked at the book then how it was set up, then it worked out at 180 degrees out. I just bought new plugs points and condenser see if that stops the missing, i guess its a process of elimination.