TR6 Diagnose my TR6 breakdown The Winner is... UPDATE

[SCguy]

So last night I too a quick 10 minute drive down I-80 to buy an apple pie. With pie in hand I jumped in the TR6 and back onto the freeway. At 70+ miles per hour my car experienced a dramatic loss of power (began blubbering and misfiring). I coasted over to an exit with the engine still running. At the exit stop sign my car sounded fine, so I proceeded to try to make it home on side streets. I got about one mile before I experienced the same thing. Then about a 1/2 a mile, then 1/4 of a mile. Each time the car would run fine but then all at once begin breaking up. After coasting to a stop, I could continue. Finally the car begin stalling as I coasted to a stop and at last I could no longer get my car to start. That's when I called a flat bed.

This morning the car started right up but didn't really want to idle and sounded a little funny. I should mention that I replaced the rotor and disributor cap last night while on the road, but that made no difference. I'm thinking coil... Any other thoughts?

 

[DNK]

Re: Diagnose my TR6 breakdown

Fuel??

 

[AltaKnight]

Re: Diagnose my TR6 breakdown

Electronic ignition could be on the fritz.
If points, could be the condenser or a gap problem (as well as the coil) probably have to keep swapping bits to figure it out.
Could also be a fuel delivery starvation problem

 

[Brosky]

Re: Diagnose my TR6 breakdown

Let's round up the usual suspects:
First of all, were you under the hood recently and what did you do?
Assuming that work is double checked, move on.
Any loose connections at coil or distributor?
Inside as well as outside?
Is the wiring from the distributor to the coil OK?
Not rubbed or chafed through?
How old is the coil?
Point gap and contacts OK? Nothing burnt?
Ground wire inside distributor OK?
Fuel filter clean or replaced recently?

 

[tdskip]

Re: Diagnose my TR6 breakdown

Larry, based on a quick read it sounds electrical to me. How is the coil?

 

[DougF]

Re: Diagnose my TR6 breakdown

I would agree with the others to look at the fuel supply. Some type of blockage that wasn't allowing adequate gas past the carbs.
As Brosky said, first check the filter.
Then chase the problem, if necessary, up to the carbs.

 

[DNK]

Re: Diagnose my TR6 breakdown

Filter problems don't usually come and go they remain. If it was fuel could be something in the pump or carbs that moves.

 

[SCguy]

Re: Diagnose my TR6 breakdown

So I'm thinking coil, then Pertronix ignition

 

[Guest]

Re: Diagnose my TR6 breakdown

Once the Pertronix quits, it quits. Coil, maybe. If you had a condenser, that would be my guess. But the Pert took care of that. Larry, you haven't left the ignition key on for more than a few minutes without the engine running, have you??

 

[TRopic6]

Re: Diagnose my TR6 breakdown

Larry,

I'm having a very similar problem (identical even) but had to wait until this weekend to start fixing it. Even though it sounds electrical, I think somethings going on with the fuel.

I first noticed a sort of roughness going through 2000 RPM, then more roughness at low speeds, and finally a "running on 3 cylinders"-type misfire. I was able to nurse it home. I changed to a Sports coil; now idles good but still suddenly starts a bad misfire. I wonder if the ethanol in the fuel is starting to affect things. Hopefully I'll find a smoking gun when I run down Paul's 'usual suspects' today.

About 2 months ago, my plastic fuel float filled with fuel and sank to the bottom of the tank - coincidence or conspiracy?

Jeff
74 TR6 CF13816U

 

[TexasKnucklehead]

Re: Diagnose my TR6 breakdown

Sounds like fuel quality or fuel delivery to me. Since it finally quit, it should be a bit easier to find now.

I carry a spare plug on the end of a plug-wire, so I can quickly tell when my rotor develops a short (etc).

Best wishes, I'd like to know what you find.

 

[DNK]

Re: Diagnose my TR6 breakdown

I carry a spare plug on the end of a plug-wire, so I can quickly tell when my rotor develops a short (etc).

Great idea, sounds like another tool for Amos's boot.

 

[Andrew Mace]

Re: Diagnose my TR6 breakdown

Could be a little bit of something floating around in the gas tank and occasionally blocks the outlet, especially when the fuel level is low. I've had this happen in various ways over the years, including:

1. Most recently, rust and/or dirt in my Herald fuel tank, although no bits big enough to completely block the outlet.

2. An acquaintance's TR6 years ago; similar symptoms turned out to be a folded-up gum wrapper foil floating around in the tank and occasionally blocking the outlet.

3. My Spitfire 4 autocrosser, in which someone apparently thought it would be...uh..."funny" to stuff a dishrag down the gas filler some time during the 1989 VTR Convention in Albany. Short-term, that little gag flopped. Problems didn't start until several years later; same symptoms again, and it took quite awhile to track down the problem. By that time, almost seven years (!) later, that dishrag had largely disintegrated, but we finally fished enough of it out of the tank to figure out what it was (or had been). And problems related to that continued for another several years (ok, the car only got very occasional use) until we finally got every last bit of the dead rag out of the tank, line and Bendix electric fuel pump.

Ah, memories.... /bcforum/images/%%GRAEMLIN_URL%%/wink.gif

 

[TRopic6]

Re: Diagnose my TR6 breakdown

Howzit Larry -
After spending the afternoon doing a general tune up on my 6, replacing the points was what fixed it. I replaced the old DPO coil with a Lucas Sports...better but still sputtered under load. After I put in the new points, the stumbling went away. The points had burned and I guess built up enough resistance to keep the coil from putting out full spark.

The car's back to running about as good as a poor ol' 118K motor can. I'm using Bosch Platinum plugs because I got them on sale cheap. I've read here that those aren't so hot and NGKs are better. What plugs do you use?

For the record, the burned points weren't all that old but have no manufacturer markings (may have come from the DPO parts box). The new ones are Lucas and I'll track them to see how they hold up.

Good luck with your breakdown repair.

Jeff
74 TR6 CF13816U

 

[Brosky]

Re: Diagnose my TR6 breakdown

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Great idea, sounds like another tool for Amos's boot. [/QUOTE]

That "boot" was long ago filled. Dale is now working in the trailer to go with it.

 

[Brosky]

Re: Diagnose my TR6 breakdown

Soooo, Larry, what was it?

 

[SCguy]

Re: Diagnose my TR6 breakdown

Coil

All is good in TR6 land once more!

 

[tdskip]

Re: Diagnose my TR6 breakdown

Coil

All is good in TR6 land once more!

Cool.

 

[DNK]

Re: Diagnose my TR6 breakdown

Larry did you go out and buy a new coil even with the 2 I was offering you?