Problem Diagnosis: May be bad

[Jeff Aronson]

While lots of owners have positive experiences with Petronix and similar electronic distributors, I've not shared those good results and I've helped other owners on the side of the road whose distributors failed them.

So, if you ask around, I'll bet someone has an old points distributor they could send to you. If you check and gap the points, and then time the car, and then run the car, you can either eliminate or confirm the distributor as the problem.

At the British Invasion a decade ago, one enthusiast joined a crew of friends doing an overnight valve job in the belief that his poorly running car suffered from a burned valve. When he fired up the car the next morning, it ran no better. A skeptic of the original plan, a man who really knows auto electrics, again offered up the spare distributor he carries with him. The car hummed like a turbine. The problem was inside the distributor all along.

Jeff

[Bostonian1976]

I had very positive experiences with Pertronix right up until this...I'm still getting another one (under warranty no less). It's definitely an easy solution but I learned that I should have a backup in the vehicle...

[Bertha]

While lots of owners have positive experiences with Petronix and similar electronic distributors, I've not shared those good results and I've helped other owners on the side of the road whose distributors failed them.

So, if you ask around, I'll bet someone has an old points distributor they could send to you. If you check and gap the points, and then time the car, and then run the car, you can either eliminate or confirm the distributor as the problem.

At the British Invasion a decade ago, one enthusiast joined a crew of friends doing an overnight valve job in the belief that his poorly running car suffered from a burned valve. When he fired up the car the next morning, it ran no better. A skeptic of the original plan, a man who really knows auto electrics, again offered up the spare distributor he carries with him. The car hummed like a turbine. The problem was inside the distributor all along.

Jeff

I agree . I am a big fan of points-no guessing with them.

[I Leak Oil]

I've had a pertronix unit for 8 years now with nothing but flawless performance. Don't leave the ignition key on without running the engine as it can burn up a pertronix just as easily as a set of points.

Nothing against points but they never stay in tune for very long. Just a gradual, but constant degradation of performance. 2.25L don't have much to lose to begin with so every little bit helps!

If you like constant tuning then go with points, If you're not scared of little black boxes then consider a pertronix....That's my take....
Jason T.

[Bostonian1976]

Don't leave the ignition key on without running the engine as it can burn up a pertronix just as easily as a set of points.

yeah - that was my mistake.....I didn't think this would behave as a set of points would...

the cell phone charge that night was not worth the burned out Pertronix

[JimCT]

worn dizzy

one advantage of an electronic, non-points set up is it pretty much ignores the wear on in the shaft bushing that might make the dwell inaccurate. Nothing rubbing against the lobes. Just a thought.

[NC Rover]

While lots of owners have positive experiences with Petronix and similar electronic distributors, I've not shared those good results and I've helped other owners on the side of the road whose distributors failed them.

So, if you ask around, I'll bet someone has an old points distributor they could send to you. If you check and gap the points, and then time the car, and then run the car, you can either eliminate or confirm the distributor as the problem.

At the British Invasion a decade ago, one enthusiast joined a crew of friends doing an overnight valve job in the belief that his poorly running car suffered from a burned valve. When he fired up the car the next morning, it ran no better. A skeptic of the original plan, a man who really knows auto electrics, again offered up the spare distributor he carries with him. The car hummed like a turbine. The problem was inside the distributor all along.

Jeff

Well considering the distributer / petronix is at least 12 - 13 years old, I'd say it might be time for a new distributor.

If anyone has a spare points distributer I could buy or borrow long enough to determine if it is the distributor, then that would be great. I'm hoping for the best, as there is no one in my area that deals with rebuilding rover engines.

[mechman]

Looking at your pictures, you seem to have a fair bit of carbon tracked onto the business end of the rotor. Have you checked the lugs in the dizzy for matching carbon? I know you said it was new, but so was the rotor, and... I've found that if there is a healthy buildup, the slightest wobble in the shaft can cause an intermittent arc on one or more cylinders, depending on where the wear is in the dizzy shaft bushing.

I'd start with the compression test, that'll tell you a lot. Compression testers are cheap and easy to use, and every shade tree mechanic should have (at least) one. If you test it dry and the compression is low, squirt a shot of oil in and take another reading. If it comes up, your rings are suspect (or a valve MIGHT not be seating correctly). If the number stays the same, you probably have either a burned valve (it'll look like a pie slice was whacked out of it) or scorched piston (the edge of your piston will have obvious damage - this is a more rare occurrence though).

I've never had a problem with Pertronix units, I love 'em, but I've heard tell of quality issues in the last few years, and 12 years is a pretty good run IMO. YMMV of course. If you're worried, carry a spare dizzy set up with points with you in your tool kit, wrapped well against moisture. I don't use points, personally, unless forced to (usually by a lack of cash flow). Technology has made them obsolete, IMO.

I HAVE had both Compufire and MSD units burn out though.

Mech

[Jeff Aronson]

Mechman is right, and you've received good advice from enthusiasts on this thread. You need to do a compression check; it's easy to accomplish and the gauge is well worth purchasing.

I am intrigued that your spark plug did not look wet or blackened on #4 cylinder. If you've actually been driving the car for any distance, then this is a pleasant surprise. A clean plug tip usually indicates proper firing and at least some compression. Again, your compression test will tell you a lot - just use the procedures outlined before this post.

However, if you're not using the vehicle very much, then your spark plug will not have much chance to load up, so the plug tip observation will not mean much.

When I had a burned valve and had to change the head for the first time, the job took me about 6 hours from start to finish, and I took my time.

I was nervous and petrified; I'd never tackled something that substantial on my Rover at the time. I borrowed a torque wrench, ordered the head gasket, the rebuilt head [my choice - I could have taken the head to a machine shop and had them install new valves instead], intake manifold gasket [might as well at the same time] from Rovers North, plenty of PB Blaster and a carbon cleaner. I opened the the Haynes Manual and followed it closely. I called Rovers North a couple of times with questions and tips on installing the new gasket correctly, and completed the job successfully.

My point to you is that if your tests indicate a valve problem, this is a job that can be tackled successfully by a mechanical novice - just as I was at the time.

Jeff

[NC Rover]

Geez so I discovered the problem. One plug wire was faulty. Sometimes it would work, sometimes it would not depending on which way it was bent. So the vibrations of the engine would cause it to connect/disconnect causing the misfiring.

Compression Check:
Cylinder 1 = 150
Cylinder 2 = 110
Cylinder 3 = 145
Cylinder 4 = 150

Going to double check the valves to see if something is slightly off causing that Cylinder 2 to be down at 110. Then maybe a leakdown test.