Engine breaking down

[Tinster]

This is a new one for me.
I took Amos out for a spin last evening and it
was deadful.

Engine cranked on first turn of the key.
Normal warmup to 160*F
Normal warm idle at 800 RMPs
Pulled away from the house normal.........

got about 30 feet, with foot in the gas, and the engine
began to stumble badly and buck. In neutral, no problem
with full range of RPM posible. Engine sounds good.

Limped home- the engine never actually shut down.

In the garage -full fuel filter at 4000 RPMs, no loose
wires I could detect. I ran the engine about 5 minutes
garaged before I turned off the key. Engine sounded real nice.

My dizzy cap and rotor are maginal- new ones on the way from PeterC.

What things make an engine act up under load but not
in neutral?

thanks,

dale

 

[Brosky]

You've already answered the question if you still have the rotor and cap on the car that were determined to be at fault earlier.

The faster the rotor spins, the more likely that there will be an issue if the rivet/electrode is loose. Isn't that what you discovered last week?

 

[Tinster]

Nope Paul,

Tony pitched the old rotor and cap in the trash bin.
A tiny metal clip was missing from inside the rotor
which allowed it some back/forth movement. It chewed
up the dizzy cap insides.

I've a decent rotor now but a somewhat chewed up
dizzy cap insides.. I ordered a new set from peterC
and they should arrive in a week or so.

I messed with the engine in the garage this afternoon.

Starts fine, warms fine, idles at 800 RPMs with full
glass fuel filter.

I give it some throttle today and it quickly falls apart;
with no change in the gas level in the filter.

If PeterC dizzy cap and rotor don't fix the problem, I am
leaning toward crud in the float bowls. I think I still
remember how to pull carbs.

BLARGH
d

 

[Brosky]

Dale,

If your cap is chewed up from the funky rotor, you may have an "arcing" condition taking place when the rpms get higher.

 

[racingenglishcars]

Defective cables, dirty spark plugs, too large spark plug gap, dielectric puncture of the rotor, etc. But really sounds like cables.

 

[Tinster]

Defective cables, dirty spark plugs, too large spark plug gap, dielectric puncture of the rotor, etc. But really sounds like cables.

Installed new coil to dizzy cable even though the existing is new.
Installed a few plug wires even though exisiting are new.
Plugs look good to me, gapped at .025
New rotor out of the box with maybe 75 miles driven. Looks good.

My thoughts keep moving over to the carb bowls.
The car starts instantly, idles smooth, good temp.

I tried to back it out of the garage for a test.
Moved 2 feet and died. Waited a few seconds, cranked back up.
Two feet forward it died again.

Waited a few seconds, cranked back up.

any more thoughts?

thanks,

dale

 

[RonMacPherson]

Tinster,


next time you have any running abnormality like this. one quick diagnostic procedure I learned along time, is to help the fuel vent system. Reach over your shoulder and pop the gas cap, leave it loose(not locked down) and see if the situation improves. If it does, that points to fuel, i.e. low pressure, restricted volume, plugged carb vent....

 

[swift6]

Have there been any backfires while you have been having issues recently?

 

[martx-5]

Did you check the points?? I don't know if you have points anymore, but just a thought. Remember, 90% of all carburetor problems are ignition related.

 

[LastDeadLast]

When I was experiencing check valve problems, it didn't matter if it was idling or not.. it just ran plain bad at any rpm. Besides with 17 fuel filters installed I would say to look at the float bowls last.

I echo what the others say, sounds like ignition.

 

[Tinster]

Have there been any backfires while you have been having issues recently?

Not a one Shawn. This engine has been running as smooth
as my Boulder Bouncer and the Mrs. Girly Jeep. I was almost
into the realm of thinking Triumphs might be reliable cars after all.

I'm not a wrench as everyone knows. But to this stonecutter, it felt
like the fuel supply was intermittant. Enought to idle but anything
more and the engine just stumbled back to idle or died.

I moved over from electric side of the car to the fuel/carb side.
I noticed my new fuel filter might have a problem.

what do you think? Wait for the new rotor and dizzy cap to arrive?

Or pull the carbs and begin rebuilding the fuel delivery system again?

How does this very fine sand get thru two filters? My carb bowls were
filled with it about 1,000 miles or so ago after a complete fuel delivery
replacement.

d.

 

[Brosky]

It gets in there from what is put into the tank. I would be really curious as to what the inside of the fuel pump looks like.

Are you sure that no one is yanking your chain down there? I mean with a little sand in the tank every day?

 

[Tinster]

Our sand isn't orange.

This stuff is so fine it goes right thru the filters.


Beats me what it is or how it gets there!!
Yeah, the pump and other filter are probably full of
it as well. Hopefully, I'll be installing YOUR fine
pump next weekend.

I;ll take many photos.

EDIT: I'm wondering here. The existing fitting in the
bottom of fuel tank draws gasoline from the very, very bottom
of the tank. I wonder if I could Rube Goldberg something so
the bottom 2 inches of the tank never enter into outlet pipe?

Remember where I live. The quality of our gasoline is not
on par with America. The big oil boys send their rejects and
bad mixes to us.

d

 

[SilentUnicorn]

I used to have an old Bonneville, and when it sat in the rain the carb bowls would get some water in them. It would start and idle just fine until you gave it some gas, then it would spit sputter and die. dump the bowls and it was good to go. sound familar?

just a thought


mark

 

[TRopic6]

Dale,

I had a similar weird cutting out problem. The plastic plug in the bottom of the front card fuel bowl had filled with sediment. Since the carb jet sticks down into it to draw fuel, it was blocking the flow and cutting out. That and the aftermarket rotor was arcing to the points post, so the #4 plug got no spark. I put an old original Lucas one in and it worked fine.

Jeff
74 TR6

 

[Brosky]

Well, it's obvious that there is probably some junk in there, if it made it through that maze of filters that Dale installed.

I wonder how much is before it in the pump.

And Dale, don't forget the seal for the top bolt on the new pump cover.

 

[DNK]

Did Dale redo his tank too?

 

[Brosky]

I think that he did it last summer during the suspesnion rebuild.

 

[NutmegCT]

From that picture, sure looks like very fine rust particles to me.

Tom

 

[Tinster]

Did Dale redo his tank too?

yup, tank removed and redone.

d