New to site - and a few problems!

So as stated i'm new to the site. I'm a young mechanic, graduated UTI in '08 and have worked on mainly honda/mazda/mitsubishi all my life. I was just given a 77 MGB, and have a few issues. I've got alot to learn about this little car, but i'm excited. Here's some backstory on the MG: The car has been sitting for 10 years. It has several new parts, but of course were new 10 years ago! Today is the first day its been touched in about 3 years. I cleaned it up and a bit and started running checks on the engine. After that, i oiled everything up and got set to let her crank. I did not hook up fuel or spark plugs, just to see if it would crank. Amazingly enough it did! Hurdle number one cleared. So the last time it was worked on seriously was about 6 years ago i'd say. From what my dad could remember, the timing was thought to be correct, but also could've been an issue. Looking at it today, it appeared to be correct. So to test we hooked up the #1 plug and attached a timing light to it. Cranked.. no light. took the plug out and set it against a bolt as a ground and cranked.. no spark. at least no visible spark. We did install an aftermarket 40k volt ignition coil, and also an aftermarket distributor. There was 12.01 volts going into the ignition coil, so clearly its got power going in. problem is, we have no way to measure the voltage (if any) is being output from the coil. So my question: is there a simple garage-trick anyone knows to see if power is being sent to the distributor? i know that theres no way to measure it, i'm basically just looking for a simple test to check for any voltage being sent at all. again i'm new to this old-school stuff so don't hold it against me! any ideas?

If current was going from the coil to the distributor, then to the plugs - what you did would've gotten a nice spark. You can do the same thing with the coil-to-distributor wire by pulling the plug from the top of the distributor and holding it near the block. Use gloves and an insulated pair of pliers to hold the boot - there's like 40kv coming down that wire. You should see spark - big spark. :eyepop:

Tell us more about the aftermarket distributor: Model, source, that sort of thing.

Oh - welcome aboard! :D

Thanks! I can get the information tomorrow, its all at my grandmas's house for now until we can get it running. I will try that tomorrow and see what happens. I'll post as soon as i get back

NAPA sells a spark/ignition tester thats adjustable for checking all ignition systems.About 16dollars.

Its got connection for plug wire at one end and a ground clip at other end..

Its has an adjustment screw that you set for your type ign sys voltage,with range markings..

Loaned mine to a club member so no PN ..Just describe it you need it ..

Brent,

Keep with it, this old school stuff is super simple once you have a handle on it. If you have a stock distributor, I would stick with that to ensure that everyone knows what you're dealing with. At the very least, post a pic of what you're using.

Start by holding the wire from the coil near the block and cranking as Rick suggested. If the distributor is working, it will run a spark to the block instead of into the dizzy cap, across the rotor, and out to the plug. If it doesn't, you may have points that aren't opening. If you have an electronic distributor, it's beyond my expertise.

If it does work, you need to set the static timing to 10 degrees BTDC. Assuming you have points (but maybe the '77 came with electronic?), you basically want to make sure that the points are opening right as the engine is hitting 10 degrees BTDC. You do this with the engine stopped, and a test light helps, but you can get close enough without it.

If you have spark from the coil, but not at the plugs, replace the rotor, it is probably grounded to the distributor shaft. If that doesn't do it, check the cap for cracks and replace if needed.

Tom

You can get one of these at most auto parts stores. You plug it between the plug wire and the spark plug. It lights up if you're getting spark. Simple and safe - and really pretty cheap.

So i will definately try holding the plug wire to the block and update what i find. I will post pics soon to show what i have to work with. I know that is not an electronic distributor, but it is not the original. The coil is a Lucas brand product i believe.. Like i said i'll run back up tomorrow and come back with more specific details. Thanks for all the input!

The issue is with the low tension side, most likely.

a quick check of the low tension side: with the cap off, power on, (and distributor power connected). use a small screw driver and flick the points open--use the rubbing block to open them. should be a spark across the points. no spark, no power. you may need to turn the engine until the points are closed then repeat. If no points -- you'll have to deal with electronic distributors...did not UTI cover that? (I dunno!)

next -- was it running when it was shut down last AND has anyone tried to "change the points"? If it was running and nobody has messes with the points, get out your circuit tracking skills (which they should have covered at UTI). If someone installed new points, they were likely installed wrong. And the problem will most likely be at the place where the wire lead to the side of the distributor attaches to the points. Look closely. there is a T-shaped insulator there to keep the lead from being instantly grounded. Very often the stuff is connected so the power is immediately grounded. Fix that and retry the flick the points. there should be a spark now.

Mac, I'd forgotten about that damned insulator. It bit me the first time I changed points in this car. Pee'ed me off so much I tossed in a Pertronix setup.

That's probably it.

After you have spark, read this.

Once again, thanks Tony RIP

http://www.theautoist.com/awakening_a_sleeping_b.htm

ok so unfortunately i didnt get to mess with the car today.. work got in the way. So to try to answer the posts... the car was NOT running last time it was worked on. I don't know if the distributor was on the car when it was running last, or later installed in an attempt to fix it. UTI was not all i expected it to be. They taught us alot on paper (distributors for example) but none of the cars we worked on had one, it was all COP or some other electronic system. If i could go back, i would've tried Wyo-Tech i think. But i'm,too far in debt to do it now! moving on, talking about tracing wires i realized i forgot to mention the engine was re-wired basically top to bottom. however i don't believe it plays a part in the problem since everything has 12v going to it. i couldn't figure out why the starter wouldn't run when the ignition was turned initially but would with straight power. tracing wires showed the wire from the starter was not connected to the relay! easy fix. anyway the pics are too big to load on here, so they are posted here:

http://s603.photobucket.com/albums/tt111/bluestreak98/

tomorrow's not looking good to get some work done either, so take a look at the pics and see what you guys think. i would love some feedback or suggestions if you see something i don't!

Brent,

Thanks for the photos. I can say for certain now that you have a standard points distributor. Don't worry about what they didn't teach you in school, this will be pretty easy once you get your head wrapped around it (and you likely already have). For the sake of completeness, though, here are the various items you should look into:

1.) Check for spark from the coil. Remove the lead from the center of the distributor cap (the other end should be connected to the coil). Using insulated pliers and some gloves, hold it against the block while cranking. John Twist has a YouTube video on how to crank various MGBs from under the hood if you don't have a remote starter button.

1. If you have spark, the Low Tension wiring is in order, the points are opening and closing, and the problem exists between the cap, rotor, wires, and plugs. Start with the rotor, they have been known to be problematic in the past few years.


2. If not, then you need to back up and look into the Low Tension ignition wiring, etc. As someone else pointed out, the problem probably exists in the assembly of the distributor itself. Watch The first video below to see how this all goes together.

All of University Motors' YouTube videos can be found here: http://www.youtube.com/user/Universitymotorsltd Take some time to watch and learn, we are all indebted to John for posting these!

Hope that helps,

Tom

Changing the Points: [video]http://www.youtube.com/watch?v=7fUbvKgmmQQ[/video]

Under-hood cranking video: [video]http://www.youtube.com/watch?v=jVxIW_pImjw[/video]

Setting static timing: [video]http://www.youtube.com/watch?v=hpp67aqwM2Y[/video]

Ok here's the update. I took the wire from the ignition coil and held it to the block. It did spark, however it didn't appear to be a very strong spark. I was expecting it to spark harder and to be able to hear it arcing. I wish i could measure the spark to see what it is actially putting out! I decided to switch to the original coil, just to see if the spark output was the same (The original i believe is 20kv). So even with half the output power of the aftermarket coil, the spark still seemed exactly the same and just as weak. I really don't know which path to take next. The plug still sees no voltage. The rotor, button, and points all seem to be fine. The car has not run under the new distributor. Like i said the ignition has its 12v coming on, but no matter which coil is hooked up, its still a weak output. The wire has 1.2 ohms of resistance so i don't see that as being a problem either. Any suggestions? Would any additional pictures help to understand what i'm working with? Here's a quick video i took today of the spark (i don't know if it will help, but i figured it couldn't hurt).

[video]http://www.youtube.com/watch?v=BbBztdjDYOY[/video]

Hard to tell from the video, but it doesn't look too weak. At the very least, you should be getting an equal spark out of the plug wires if the rotor, cap, and wires are in order. If you aren't, then you have a problem between where the spark enters the top of the cap and where it comes out of the wire end.

Try the same thing you did with the coil wire, but with one of the plug wire ends. Also try it with the spark plug connected to the wire and the plug grounded to the block. While you may have a weak spark (or you may not), you certainly have a problem with the rotor, cap, or wires if the spark doesn't transfer out to the plug. My bet would be on the rotor, but if you have a spare cap, wire, and/or plugs, try them, too.

Tom

Brent Look up" Kettering ignition system" you will quickly pick up how it works.and then easily fix the problem. Some things to remember,. The spark occurs as the points open and the dizy may have been fitted 180* out of wack. Also if the car has been sitting around a long time you may need to clean or file the contacts as they may be making a poor contact which will effect coil output. Good luck with it Denis

Welcome! There are some good, color coded FREE wiring diagrams on the web, but I can't recall the site right now.

Also some great books, starting with the Haynes manual for MGB, and the Roger Williams book on "fixing problems on the MGB and MGB GT". These two go together very well.

That spark didn't look too bad to me either. Your gas is going to be junk, so you will need to drain the tank CAREFULLY, and it will smell horrible. Dispose of it properly, just don't pour it out behind he house!

Somebody gave you a link to Ton's site, about awakening an sleeping B. Right on the money.

Also be aware that your rubber brake hoses (all 3) will need to be replaced due to their age. The design often lets them fail on the inside, and the outside looks fine.

Just have a little patience, and you will be good before you know it! Also, look for a possible British or MG group in the area, and I think there are some other WV folks on board here too.

One thing that sets MG folks apart is their almost undying desire to help eachother out.

Post some pictures of the car when you can, we all enjoy seeing what folks are doing!

I agree with others it is quiet possible the distributor got mounted 180 degrees out of phase. Easy to do, and easy to fix.

Also realize you can get a fair amount of parts locally, and aren't always tied to ordering from a catalog. Also, the B-hive in SC is a great place to get parts from, and Gordon

was a trained in England MG mechanic! http://bhive.tierranet.com/

You truly can't beat the John Twist videos, I go there often!

William

As mentioned, rotors can be a problem. Get one or more of these:

http://advanceddistributors.mybisi.com/product/4-cylinder-ignition-rotor

Jeff is a member of this site and is the dizzy Guru.

I would also suggest an electronic ignition, if possible.