*grumble* MG runs like poop, and some other stuff

[Rupert]

*sigh*

Such things are par for the course with these cars, but it's annoying, nonetheless. Today I finally had enough time to sort ofget through the ignition stuff (which is plugs, wires, cap, rotor, points, condenser, timing, and a fancy new Lucas Sports coil). I checked the compression, too.

I didn't get everything done because I am confused about the timing marks on the timing belt cover, so I couldn't get the distributor out to replace the points and condenser because I couldn't re-time it. I replaced the coil, and it ran fine. I replaced the plugs, and it ran fine. I pulled the wires, cap, rotor, and realized I couldn't easily and accurately do the points and condenser without pulling the distributor. I poked around the points a bit, theoretically not knocking anything about.

I put the new rotor on, though it didn't seem to want to fit. I put the cap and wires on. It didn't start. I pulled the cap, etc., and replaced the new rotor with the old (because it seemed like the new one wasn't fitting right), and put the old cap on (because I knew it worked with the old rotor). It started, but ran like total shit at low RPM. It sounded like the timing was off, but I didn't knock the distributor, did I? Maybe I knocked the points out of adjustment, or maybe the new rotor did that when I was trying to start the car before? I'll be out of town (of course) for the next bit, but I think the next step is to basically finish the job. Pull the distributor, replace points/condenser, adjust timing. I will probably get a different rotor eventually.

Then, there's the compression. I got, in order from cylinders 1 to 4: 130, 115, 150, 150 psi. Way more than the 10 % variation I want, so there's something up in the first couple of cylinders. I'm not sure what to do about this, because I don't want to pay to have the head rebuilt ($$!), and I don't have the patience/skill/space to do it myself. When the car runs, it does so pretty well. I'm temped to just let it be, but I don't know what I'm risking by doing that. I guess I should do a little more research about how much it would cost to get the problem fixed. The other option is sell the car and try again...

Any ideas on the crappy running or bad compression? 

[Cookie Monster]

I don't know how to help you but I wouldn't sell the car, unless you're going to buy a Miata.

[Rupert]

Or a Fiat, or an Alfa... But, yeah, I like this car. It's solid, but bad compression is, uh, bad.

[Eye of the Tiger]

pfffft.... that compression will be fine, as long as it's not the head gasket or valves

[Rupert]

Which it probably is. The MG expert on YouTube (odd idea, I know) says it's usually the exhaust valves.

[Eye of the Tiger]

oh yeah, did you do a wet compression test? squirt a bit of oil down there and do it again. this will tell you if of's the rings or something else

[Rupert]

I didn't do that. How much oil? Couple of drops, or an ounce or so? If the compression is better during the wet test, that means the rings are bad?

[Eye of the Tiger]

right, the oil would sedl up the rings if they are the problem, so the numbers should go up a lot. just put a bit down there, like a tablespoon or so.

[Rupert]

http://www.mgexperience.net/phorum/read.php?1,994443,994443#msg-994443

^ Thread on the MG Experience forums about this...

[Laconian]

So is this what the MG Experience is like?

[Rupert]

Apparently...

I knew what I was getting into, this time, though.

[GoCougs]

I personally have put distributors in off by a tooth or two (not sure if this is possible with this engine), and got the exact same results.

115 vs. 150 is a pretty big variation, but meh - if in ain't blowing blue smoke or eating a quart every 250 miles, I wouldn't worry about it.

[JWC]

I personally have put distributors in off by a tooth or two (not sure if this is possible with this engine), and got the exact same results.

115 vs. 150 is a pretty big variation, but meh - if in ain't blowing blue smoke or eating a quart every 250 miles, I wouldn't worry about it.

I'm with Cougs here, if it runs (when it runs) and shows none of the outward signs of failure that he mentioned, I would not pull that head.  I see minor problems all the time that people want chased down because they think it is worse than it is.   Car repair hypochondria. 

On of my VWs showed 90 on #3, the cylinder that always burns a valve, while the others are hovering around 120-130.  Doesn't use oil, doesn't leak oil, doesn't smoke and it doesn't misfire.   Still gets 28-30 on the highway.

If you were "fiddling" with the points, even a small amount of grease or dirt can cause a no start.   Been there, done that.  Take a Q-tip, or a lint-free cloth,  and swab the contact surfaces with alcohol. 

[Byteme]

*sigh*


I put the new rotor on, though it didn't seem to want to fit. I put the cap and wires on. It didn't start. I pulled the cap, etc., and replaced the new rotor with the old (because it seemed like the new one wasn't fitting right), and put the old cap on (because I knew it worked with the old rotor). It started, but ran like total shit at low RPM.


Then, there's the compression. I got, in order from cylinders 1 to 4: 130, 115, 150, 150 psi. Way more than the 10 % variation I want, so there's something up in the first couple of cylinders. I'm not sure what to do about this, because I don't want to pay to have the head rebuilt ($$!), and I don't have the patience/skill/space to do it myself. When the car runs, it does so pretty well. I'm temped to just let it be, but I don't know what I'm risking by doing that. I guess I should do a little more research about how much it would cost to get the problem fixed. The other option is sell the car and try again...

Any ideas on the crappy running or bad compression? 

Runs like crap:

The E-type owners lists have also noted a bunch of bad rotors lately.  Foreign made crap that doesn't really fit.  I'd try putting the old cap back on as well and see if that makes a difference.  If not then you have done something to the points or timing, or perhaps you have a bad plug wire.  Make sure you have the dist cap properly seated when you reinstall it.  Not a biggie, just take your time and work your way through it.


Compression:

Could be a biggie.  150 pounds sounds about right if you have an 8 to 1 compression engine.  You want a variance of no more than 10%.  First do the wet compression test as others have suggested.  a tablespoon should be enough for each cyl.  When you do the tests make sure you have the carb butterflys wide open (or the carb piston all the way up if you are talking SUs).  Follow the directions that came with the tester.  If the reading goes up it's rings, if not it's a head gasket or valves. 

You should hope it doesn't go up.  A head gasket and/or valve job is much less hassle and expense than rings.

[Rupert]

Thanks for the suggestions, guys. I'll check the list when I get back next weekend.

I'll do the wet compression test, but it's not blowing blue smoke, so that's a good sign. I'm not sure about oil consumption. I haven't driven it that many miles, and it does leak like a 17th century trade ship. I suppose I'm not too worried about it, since it runs well.

I tried with the old rotor and cap, and that's when it started but ran poorly. The folks at the MG Experience board suggested looking for physical damage to all those plastic ignition parts, so I'll do that, too. I'll try with the old plug wires, just to be sure.

But now I must drive off to Seattle!

[S204STi]

Thanks for the suggestions, guys. I'll check the list when I get back next weekend.

I'll do the wet compression test, but it's not blowing blue smoke, so that's a good sign. I'm not sure about oil consumption. I haven't driven it that many miles, and it does leak like a 17th century trade ship. I suppose I'm not too worried about it, since it runs well.

I tried with the old rotor and cap, and that's when it started but ran poorly. The folks at the MG Experience board suggested looking for physical damage to all those plastic ignition parts, so I'll do that, too. I'll try with the old plug wires, just to be sure.

But now I must drive off to Seattle!

There are retrofit kits for those distributors, btw, which may improve ignition system performance.

Oh and have fun in Seattle, it was pretty with a bit of snow on the ground when I flew through there sunday night.

[Laconian]

It's pretty much melted except for the piles left behind by the snowplows.

[S204STi]

Oh good.  When I passed through on the weekend of the 20th I heard stories about folks abandoning cars and whatnot... kinda odd over five inches of snow till you realize that seattle doesn't get much snow so their ability to remove it is limited.

[Laconian]

We throw sand on everything, because it's more environmentally friendly than salt...

but recently we found out that it isn't...

yet we do it anyways...

[Soup DeVille]

We throw sand on everything, because it's more environmentally friendly than salt...

but recently we found out that it isn't...

yet we do it anyways...

Salt at least washes away with the rain.

[Secret Chimp]

Salt at least washes away with the rain.

But da wildlyfe!

[Soup DeVille]

But da wildlyfe!

Thinks salt tastes better than sand too!

[JWC]

But da wildlyfe!

Salt licks are set out for wild life...as well, as horses and cattle.

Ok, so hunters actually set out salt licks to draw deer out into the open.  So, I guess salt is bad for wild life.

[Soup DeVille]

Salt licks are set out for wild life...as well, as horses and cattle.

Ok, so hunters actually set out salt licks to draw deer out into the open.  So, I guess salt is bad for wild life.

Not quite as bad as lead.

Especially 168 grains of lead traveling at 2700 feet per second.

[Rupert]

So, ahem, apparently, I might be in idiot. I went out to move the car out of the garage this morning, and it started right up! I drove it around until it was warm, and it ran great. So I'm not sure what was up last night... Maybe I flooded the engine and didn't give it enough time to recover? I gave it five or so minutes... Oh well, all is well now, and disregard this thread.

0_0

[Tave]

I'm wondering if it's a common problem among car guys. Some days I get behind the wheel, and nothing seems to go right. The engine sounds off, the handling feels sloppy, and I can't shift worth a damn. Then I climb in the next day, and everything feels perfect, and I'm one with the car.

[Rupert]

Must be the milk I had with breakfast...

[S204STi]

I can sympathize with that.

[Eye of the Tiger]

I'm wondering if it's a common problem among car guys. Some days I get behind the wheel, and nothing seems to go right. The engine sounds off, the handling feels sloppy, and I can't shift worth a damn. Then I climb in the next day, and everything feels perfect, and I'm one with the car.

It seems to happen when I get too used to driving a particular vehicle. It's good to take a break and drive something else for a while, then get back to it. Re-getting-used-to a car forces me to pay more attention to my senses, and therefore make improvements.

[Rupert]

I probably got too confident with my mechanical abilities/methods.