Rough Running Engine

[NelsAnderson]

A few weeks ago my engine starting running rough and I have not been able to fix it so could use some help.

1963 Series IIA 109 Station Wagon
Turner 2.25 rebuild engine
Weber 34ICH carb

I first thought it was just an idle problem, so changed the inline fuel filter, removed and cleaned the idle jet and removed and cleaned the filter screen. No effect.

Actually, it runs rough at all speeds. It's not really noticeable just listening to the engine, but is obvious listening to the exhaust. There's also a noticeable lost of power when driving.

I have since done the following, all with no effect:

Removed and checked spark plugs: all nice and tan

Removed distributor cap, cleaned contacts, adjusted gap

Removed wires from coil, cleaned contacts

Opened top of carb, check bowl for sediment (nothing found), cleaned out bowl and blew carb cleaner through jets (though did not remove them...not sure how, do they just unscrew?)

Clamped off vacuum hoses to check for leaks

Sprayed carb cleaner around base of carb to try and detect vacuum leaks there

Tried clearing carb by putting hand over air intake and letting it suck until it almost stalls

None of this seemed to have any effect. I am not experienced on this kind of thing so it's possible I've just failed to notice something, but at this point I'm out of ideas. Any suggestions would be appreciated!

[Les Parker]

Have you checked the adv/retard vacuum unit on the distributor?
Try disconnecting it and see if it runs any different.

[NelsAnderson]

Does that mean simply removing the vacuum advance hose from the distributor? I haven't tried that but it sounds easy enough to do. Thanks!

[daveb]

I didn't see where you adjusted the valves. Adjust the valves and see if that helps.


A few weeks ago my engine starting running rough and I have not been able to fix it so could use some help.

[bmohan55]

Plug wires??? Switched mine out and it got rid of the "burp" in the exhaust.

Also an easy trick taught to me by an old mechanic is to hold a dollar bill (for a Series use a $20) and see if it gets intermittently sucked towards the exhust pipe, if so you've got a burnt valve.

[Les Parker]

Yes, just pull the pipe from the dist. vac. unit and plug with a small bolt.
See if it makes a difference, plus try the dollar bill burnt valve detector !

[NelsAnderson]

OK thanks everyone. Let me now follow up.

The spark plug wires are only two years old, a rather expensive set of Magnecor wires that are supposed to last forever, so I would hope that's not it.

I have not adjusted the valves. I've never done that before so I'm a bit reluctant, though maybe that is the logical next step?

I checked the distributor vacuum advance. If I understood right, the hose is removed from the distributor and a bolt stuck in the hose to plug the vacuum leak. I tried running that way, but did not notice any difference.

While it was running I tried the (twenty) dollar bill test. The bill flaps around in the exhaust which seems to always blow out, with each "puff" blowing a little harder. I really didn't want a burnt valve so I guess this is good news.

[graniterover]

Nels,

I'm 99% sure you have hardened valves.

Did this happen all of the sudden, or gradual?

Mark


OK thanks everyone. Let me now follow up.

The spark plug wires are only two years old, a rather expensive set of Magnecor wires that are supposed to last forever, so I would hope that's not it.

I have not adjusted the valves. I've never done that before so I'm a bit reluctant, though maybe that is the logical next step?

I checked the distributor vacuum advance. If I understood right, the hose is removed from the distributor and a bolt stuck in the hose to plug the vacuum leak. I tried running that way, but did not notice any difference.

While it was running I tried the (twenty) dollar bill test. The bill flaps around in the exhaust which seems to always blow out, with each "puff" blowing a little harder. I really didn't want a burnt valve so I guess this is good news.

[kevkon]

Do you buy your gas at the same station all of the time? Any change in fuel in the last couple of weeks?
If not;
While your engine is running pull the plug wire off one cylinder at a time. If one comes off and no change is noticed in the engine you have your culprit.

[willincalgary]

Yes, just pull the pipe from the dist. vac. unit and plug with a small bolt.
See if it makes a difference, plus try the dollar bill burnt valve detector !

What's this dollar bill burnt valve detector? I had to use a five dollar bill as we don't do the one dollar bill up here. It flapped out and then smacked back against the tailpipe quite rhythmically. Diagnosis of test results anyone?

[Nium]

Also an easy trick taught to me by an old mechanic is to hold a dollar bill (for a Series use a $20) and see if it gets intermittently sucked towards the exhust pipe, if so you've got a burnt valve.

A compression test may be a good idea willincalgary.

[NelsAnderson]

Nels,

I'm 99% sure you have hardened valves.

Did this happen all of the sudden, or gradual?

Mark

I'm not sure I understand what you mean by "hardened valves".

For as long as I can remember, I've always heard the occasional "puff" from the exhaust. The current problem happened pretty suddenly though, one day running good, the next day running rough.

The engine (Turner high performance) was new in March 2005 and has only 14,500 miles on it so I wouldn't be expecting valve problems already.

[NelsAnderson]

Do you buy your gas at the same station all of the time? Any change in fuel in the last couple of weeks?
If not;
While your engine is running pull the plug wire off one cylinder at a time. If one comes off and no change is noticed in the engine you have your culprit.

I usually buy gas for all three of my vehicles at the same station down the street from my house, though I cannot say for sure that I remember if I did that on the last tank of gas in the Rover.

Is it safe to pull the plug wires like that? Pretty high voltages there.

[bmohan55]

What's this dollar bill burnt valve detector? I had to use a five dollar bill as we don't do the one dollar bill up here. It flapped out and then smacked back against the tailpipe quite rhythmically. Diagnosis of test results anyone?

Your exhust valve is either burnt or not sealing all the way due to carbon build-up, thus the "sucking" action during the piston's down stroke.

Compression test would confirm. BTW, DO NOT wade thru deep water with tail pipe sucking in...bad things happen!

Nels...in reading through your posts, if you have not adjusted the valves in 14K miles I would do so now. Here a good how-to
http://www.lrfaq.org/Series/FAQ.S.tuning_2.25l.html

[Nium]

Is it safe to pull the plug wires like that? Pretty high voltages there.

Not with your bare hand. You need to use some sort of insulating device, such as a pair of plug pliers, to keep the voltage from using your body as a conductor to ground. Plug pliers are made of non-conductive material and are available at auto-parts stores.

[NelsAnderson]

Well, I think I made some progress this afternoon.

I wasn't sure how to remove the carb jets but I decided to remove the top of the carb again and have another look. The main jet appeared to just screw out and sure enough it did just that. Looking through it the opening looked like a thin slit, which didn't seem right. A blast of carb cleaner through it and a much larger round hole appeared.

Starting the engine I was now getting white smoke out the exhaust, which I take to mean with the larger jet opening it was now running too rich. I turned in the adjustment screw and was able to make the white smoke stop.

But it's still running rough. I tried the hand over the air intake to try and finish clearing things. This seemed to help, but only briefly (the RPMs would go up and some times the puffing from the exhaust would actually stop for a second or two).

So I'm guessing I need to continue clearing things. Looking at the diagram, the fuel flows past the main jet into the emulsioning tube and air correction jet. It's not clear, does that just unscrew too? If so, that will be easy to clean.

There's also the pump jet. I don't see how that comes out though, any ideas?

Are there any other jets or whatever that might also need to be removed and cleaned?

[kevkon]

White smoke = oil ( it might also be from the cleaner you used)
Try pulling the plug wires one at a time ( yes you want to do this with insulation) see if you don't notice any difference in the engine.
I still wouldn't rule out bad gas. Look for any presence of water or debris in your sediment bowl or filter.

[Nium]

Does the white smoke continue after the engine is at operating temperature? If so you may have a blown head gasket.


When the engine is cool remove the radiator cap.
Place the Landy so the top of the radiator is above the head. Jack up the front and put it on stands or park on an incline.
Start the engine. With the radiator cap off or just set the cap in the top of the radiator and not screwed down so you can remove it before it's hot.
Check if there is a continual stream of bubbles coming to the top of the radiator once it is at operating temperature (the thermostat is open and the upper radiator hose is hot). If there a continual stream of bubbles you've probably got a blown head gasket.
If you only get white smoke for a little bit after starting the engine then it's probably not coolant leaking past a blown head gasket into the cylinders but just condensation in the exhaust pipes burning off till warmed up.

Or a compression test could be useful in diagnosing the engine.

kevkon didn't you mean?
white smoke=coolant
blue smoke=oil
black smoke=excessive fuel

[Nium]

Sorry, I hadn't noticed you had already written that the white smoke had stopped when you turned the adjustment screw. :o

An old school trick you might could try, with the engine at operating temperature and running, slowly pour a full cup (8 oz) of water down the carburetter throat. The water will turn to steam in the cylinder and help to loosen up carbon deposits and break them up so they are blown out the exhaust. You just have to pour slowly, just a little trickle, till it's all gone. You don't want to stall the engine.

[NelsAnderson]

I probably got the color of the smoke wrong. It was rather cloudy and dark when I was working (needed a light under the hood to see the engine). But I think the key is:

No smoke initially.

Enlarged hole in primary jet: smoke from exhaust started.

Turned in mixture screw: smoke stopped.

Unless I'm really clueless on this, that pretty much means the mixture got too rich when the jet was opened up.

So I think more cleaning of the carb is the next step. The cup of water down the throat it something I wouldn't have thought of but I'll give that a try...thanks!

I'm still unclear about the other jets and passages. Is that a second jet at the bottom of the bowl I need to remove and clean? Can the air correction jet just be unscrewed and cleaned? How do you remove the pump jet? That probably needs cleaning too.

[jac04]

Here is some good info:
http://www.aloharovers.com/tech/ichoverhaul.htm

[NelsAnderson]

Here is some good info:
http://www.aloharovers.com/tech/ichoverhaul.htm

Oh, that is a good article, thank you.

Well, I made use of that. Didn't do the whole tear down and rebuild but did use it as a reference to open up the carb, remove things and blow them out. The only thing that still stumped me was how to remove the air tube. The air jet that's right above it unscrews and comes out but then the air tube is sitting there down inside the cavity with nothing to pull on to get it out. So all I could do with that was blow carb cleaner through it while it was in place.

Well, after blowing out everything that I could remove and re-adjusting the idle speed and mixture, the end result is that nothing has changed. It runs just as rough as when I started. I really thought finding and clearing the clogged main jet I was on to something but clearing that didn't actually do anything other than make it run rich :-(