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TR6 Hesitation, while turning, I'm stumped.

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BwanaJoe

BwanaJoe

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I have a 72 TR6 that I've recently had the carburetors rebuilt, fuel pump replaced, the gas tank replaced, and the metal fuel lines all replaced. The
Car idles fine and pulls like a train in third and fourth gear. Despite all this, I still have a problem with the car hesitating and bogging down if I'm making a hard left hand turn in first and second gear. RPM is generally around 2000 in second, but, I've had it in first at around 1000 RPM in a sharp U-turn. Fuel tank level doesn't make a difference. Dash pots are filled. Coolant temp doesn't seem to matter. I haven't experienced a problem turning right. As far as straight ahead travel, there MAY be a stutter in second, but it is so faint I may be reading into things right now. If I drive like a little old lady the car seems to run fine. I'm completely stumped. Any help would be appreciated.
 
BwanaJoe said:
I have a 72 TR6 that I've recently had the carburetors rebuilt, fuel pump replaced, the gas tank replaced, and the metal fuel lines all replaced. The
Car idles fine and pulls like a train in third and fourth gear. Despite all this, I still have a problem with the car hesitating and bogging down if I'm making a hard left hand turn in first and second gear. RPM is generally around 2000 in second, but, I've had it in first at around 1000 RPM in a sharp U-turn. Fuel tank level doesn't make a difference. Dash pots are filled. Coolant temp doesn't seem to matter. I haven't experienced a problem turning right. As far as straight ahead travel, there MAY be a stutter in second, but it is so faint I may be reading into things right now. If I drive like a little old lady the car seems to run fine. I'm completely stumped. Any help would be appreciated.
Click to expand...
I had this same problem on an early TR6 with new S.U. carbs. The problem was caused by the orientation of the floats. The floats were rotated and problem solved. I suspect you may not have SUs but I suggest you concentrate on the carbs and the fuel flow.
Charley
 
charleyf said:
I had this same problem on an early TR6 with new S.U. carbs. The problem was caused by the orientation of the floats. The floats were rotated and problem solved. I suspect you may not have SUs but I suggest you concentrate on the carbs and the fuel flow.
Charley
Click to expand...
By rotated, do you you flipped them over but used the same orientation? And no, they are ZS carbs.
 
BwanaJoe said:
By rotated, do you you flipped them over but used the same orientation? And no, they are ZS carbs.
Click to expand...
On the SU carbs the float chamber is located outside the main part of the carb. We were able to rotate the lid with float attached so that both floats were not reacting to the g force of the hard turn. They were apparently closing the flow of fuel. Hope this helps.
Charley
 
How long does it take for the engine to recover...as soon as you straighten out or how much longer ?
 
Hamish Racing said:
Sounds like ignition to me. I don’t think carbs would react that quickly to a turn
I’d look at the low tension wire to coil being pulled on the turn or similar.
I’d initially jack up the front and have someone turn the steering wheel whilst you look under the hood for tightening /loose wiringi
Click to expand...
I did check for binding wires, but I'll check with someone turning the wheel. As an aside, it has a Petronix coil and under the cap ignition system.
 
Late response but - i have the same issue. the hesitation (engine spluttering) lasts for a couple of seconds on tight left turns, usually pulling away from traffic lights, and then the motor recovers and all's back to normal. did you find the cause of the problem?
 
Hamish Racing said:
Sounds like ignition to me. I don’t think carbs would react that quickly to a turn
I’d look at the low tension wire to coil being pulled on the turn or similar.
I’d initially jack up the front and have someone turn the steering wheel whilst you look under the hood for tightening /loose wiring.
Click to expand...
There aren't any wires near the steering column but I checked anyway. The HT leads are all plugged in solidly and there are no breaks or bare spots. The LT lead is the same. I also poppeld the dizzy cap and checked the Pertronix moduule was still secured properly. (As an aside the cap and rotor are fine)
 
USTR5 said:
Late response but - i have the same issue. the hesitation (engine spluttering) lasts for a couple of seconds on tight left turns, usually pulling away from traffic lights, and then the motor recovers and all's back to normal. did you find the cause of the problem?
Click to expand...
Nope. The next step is yanking the carbs. But, that will be in May. For now I'll drive like a little old lady on Sundays...
 
USTR5 said:
Late response but - i have the same issue. the hesitation (engine spluttering) lasts for a couple of seconds on tight left turns, usually pulling away from traffic lights, and then the motor recovers and all's back to normal. did you find the cause of the problem?
Click to expand...
BTW, ZS carbs, and what year of car?
 
I don't think it's carbs either....the jet is deep in the float chamber actually down into the plug.. and you'd have to be down to the last drop of gas before the engine even sputtered.
Here's a picture of the bottom of the jet where the gas gets sucked into:
ZS carbs jet pick up.JPG
 
If it isn't the carbs at this point then I am truly at a loss. I don't know where in the iginiton system the problem is manifesting if that is the culprit. Short of doing an expensive "let's replace parts until it goes away" I'm not sure how to even test anything at this point. Guess I can check the timing but now I'm grasping at straws...
 
Try this.
Driving in 2nd gear so as not to be going all that fast in miles per hour during this test.
While driving in a straight line run the engine up to 4200 rpms and hold it there for 15 seconds. Does the engine start to sputter and buck ?
 
BwanaJoe said:
If it isn't the carbs at this point then I am truly at a loss. I don't know where in the iginiton system the problem is manifesting if that is the culprit. Short of doing an expensive "let's replace parts until it goes away" I'm not sure how to even test anything at this point. Guess I can check the timing but now I'm grasping at straws...
Click to expand...
We got our answer from Joe Curto the SU guru. Maybe he can help you with your Strombergs as well.
Charley
 
It sounds like a fuel sloshing problem to me...as in it is sloshing out of the bowl into the engine. I am not familiar with ZS's enough to say why or how to fix it, though. The SU's have that problem during braking, and it often gets better by lowering the fuel level a tad in the bowl.
 
poolboy said:
Try this.
Driving in 2nd gear so as not to be going all that fast in miles per hour during this test.
While driving in a straight line run the engine up to 4200 rpms and hold it there for 15 seconds. Does the engine start to sputter and buck ?
Click to expand...
No problems.
 
Then your fuel pump is delivering plenty enough fuel to the carbs.
 
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