TR 3 Missing badly at all speeds

[Camping57]

After being off the road for almost two years with a broken rear end (the car, not me), I finally got my TR 3 back together again. While I was waiting for the rear end to be rebuilt I put in new points, condensor and plugs. Now the car has a very bad miss at all RPMs.
I pulled the plugs and they are all very sooty looking, so I got out my Colortune thinking it was way rich, but the mix didn't look very far off.
The miss is so bad that I have to tickle the throttle to keep it idling and it doesn't smooth out at speed at all, it still misses at all engine speeds.
Anyone have any ideas what I managed to do to my car?
My first guess is that I messed up the points change somehow, and I am the first to admit that I know very little about how to set points.

Dick

 

[Don Elliott]

Check the cables to the spark plugs. Sounds like you put the cable for #4 on plug #3 and vice versa. Switch them and get back to us.

Don Elliott, Original Owner, 1958 TR3A

https://www.britishcarforum.com/ubbthreads/photopost/showphoto.php/photo/1919/ppuser/4127

 

[Camping57]

I'll check that. I don't think I did that, but I've done MUCH dumber things in the past. I'll also check the resistance on wires to make sure that I don't have a break somewhere.
If it is a plug wire it seems funny that all the plugs have the same super sooty look to them. It's kind of fluffy looking. Does that help anyone with a diagnosis?
Could it be the plugs? I went one heat range colder and switched to NKG from Champions.

dick

 

[martx-5]

[ QUOTE ]
... I went one heat range colder and switched to NKG from Champions.

dick

[/ QUOTE ]

That could be the problem. If you still have the Champs, put them back in and see if it cures the miss.

 

[Camping57]

Of course I tossed the old ones. Time to make a trip to the farm supply store for some new Champions.

Dick

 

[John_Mc]

I can only give advice based on experiences I have had, and I have had two experiences where the car ran rough as you described, and in both cases it was remedied by resetting the points. It's been so long since I've done it, I can't remember all the specifics (and both times it was on Volkswagens, but I think the anatomy of distributors is same) but it's really a simple procedure. That may not be the problem at all, but if it is, it's a quick fix.

 

[Don Elliott]

Dick - To set the points gap, remove the distributor cap. With it in neutral, turn the engine with the hand crank. Or pull on the fan blades towards you at the top of the fan when you are standing near the distributor. When you see the points are opening at the highest point on the cam for the dizzy, stop turning. Then insert a feeler gauge with 0.015" thickness and adjust the gap back to that setting. Test it again. If you can see of feel a "spike" on one face of the points, you will have a "pit" just opposite on the other face of the points. I suggest you buy new points. But as a quick fix, you can file off the "spike" and re-gap the setting to 0.015". The spike means that the points are old and burnt. It may have been caused by age or if you left the ignition switch on too long with the points touching.

 

[Camping57]

Thanks guys, it's great to get info like this. Bentleys doesn't have the basic things like this.

When I set the points I pulled the fan to the right, away from the dist. Could there be enough backlash in the system that I could be off because of that? (should I even bother asking that question about Lucas and LBCs?)

I will recheck the dist setting. How about dwell? I have never understood how to set the dwell? Is there any way to do it without a dwell meter?

Dick

 

[Deleted member 451]

If the gap is set right then the dwell is OK.

 

[Don Elliott]

In 48 years, the only time I had the dwell checked was when I was in Portland Oregon having some work done on the overdrive and the distributor.

 

[Andrew Mace]

[ QUOTE ]
When I set the points I pulled the fan to the right, away from the dist. Could there be enough backlash in the system that I could be off because of that?

[/ QUOTE ]In a word...YES! If you "miss" the high point of the distributor cam when turning the fan in the normal direction of rotation, keep going until you get to the next one. Doesn't matter which lead the rotor would be pointing to when setting the gap.

Oh, semi-useful tip of the day: in a pinch, a matchbook cover will be a sufficient feeler gauge for temporarily setting points. /ubbthreads/images/graemlins/smile.gif

 

[Dave Russell]

[ QUOTE ]

If it is a plug wire it seems funny that all the plugs have the same super sooty look to them. It's kind of fluffy looking. Does that help anyone with a diagnosis?
Could it be the plugs? I went one heat range colder and switched to NKG from Champions.
dick

[/ QUOTE ]
The "one heat range colder" could certainly be the cause. The sooty, fluffy look would indicate that the plug is too cold.
D

 

[Camping57]

Well, I have to go out of town for business until the weekend, so I won't have a chance to work on the car until then. It sounds like a new set of plugs are in order and a double check of the gap on the points.

Thanks for all the good advice, you guys are great.

I'll report back once I have had a chance to work on it some.

Dick

 

[BobSands]

A "trick" Ive learned with setting points, is put the car in 4th gear, then move it until you get on the cam lobe. This uses the weight of the car to overcome compression. Bet it's the points, cap, or rotor...
Take care Bob

 

[TR4nut]

I use the same trick of putting the car in gear - it makes it very easy to get the distributor lobe lined up where you want it.

Very minor disagreement on the other method (hand turning the fan) - as long as you get the lobe lined up with the points for max opening, I don't think it matters what way you turned the fan, the gap will be correct. Now if you are messing with static timing and you have slop in the timing chain, then you might get into trouble on how you turn things.
Good luck!
Randy.

 

[Andrew Mace]

[ QUOTE ]
Very minor disagreement on the other method (hand turning the fan) - as long as you get the lobe lined up with the points for max opening, I don't think it matters what way you turned the fan, the gap will be correct.

[/ QUOTE ]Right, Randy. (duh on my part) I was thinking timing when I typed that! /ubbthreads/images/graemlins/crazyeyes.gif

 

[Camping57]

Update on what fixed the problem.
I went through and rechecked the point gap (about .003 too wide) and it did nothing. Checked all the plug wires: nothing. Cleaned the spark plugs: nothing. Replaced in-line fuel filter: nothing. Put in a new set of the correct heat range plugs: FIXED!
I can't believe how much of a difference increasing the heat range by one step improved the car. There is absolutely no miss at all now. So; remember this the next time you have an odd miss.
By the way; the reason I went one heat colder was because my normal source for plugs only had the colder ones. Yesterday I went down to a long time parts store in town here and asked for for a set of RL87YC plugs. The counter man said that they had some but that they were in a bulk jobber pack and he would like to close them out. So I got them for $1.29 each! I'm going to go back today and buy the rest of his stock to keep on hand.

 

[Andrew Mace]

So what did you have before...L82Y plugs, or even colder than that? I'm also surprised that this change would have made that much difference...but then some of these cars can be fussy. My Herald 1200 seems as happy on L82Ys as it is on L87Ys, yet it absolutely INSISTS upon winter or summer thermostats for proper coolant temperature range for the respective seasons. Go figure!