HKforte
SILVER Star
Hey guys...I've done as much research and troubleshooting as possible on this one and I just need to ask for more help.
My uncle's 1972 FJ40 (stock engine) keeps hesitating upon acceleration, although the engine idles very smoothly. It hesitates the most when the engine is under load or when you step on the gas abruptly.
The following changes have been made to the vehicle (one by one) in order to solve the issue. Although the hesitation problem has not been resolved, it has been reduced as a result of the following changes:
Where do I go from here? I first thought I had a fuel delivery problem, then I started looking at the electrical stuff, and everything else mentioned above. Your help is greatly appreciated.
My uncle's 1972 FJ40 (stock engine) keeps hesitating upon acceleration, although the engine idles very smoothly. It hesitates the most when the engine is under load or when you step on the gas abruptly.
The following changes have been made to the vehicle (one by one) in order to solve the issue. Although the hesitation problem has not been resolved, it has been reduced as a result of the following changes:
- Valve adjustment (no sticking valves or tight clearances)
- New gas tank (old tank had too much rust inside), new fuel lines, fuel filter. I tried installing my spare fuel pump to see if that was the issue as well, and no change in hesitation.
- Stock Carburetor rebuilt by 65swb45 (Thanks Mark) The carb now has the correct accelerator pump which it did not have before.
- Wiring harness from key switch to coil, regulator checked and cleaned.
- battery cables, ground connections checked/cleaned
- new distributor cap, spark plugs, plug wires, regulator, air filter
- electronic ignition (Petronix) installed with new coil. Point, condenser, ballast resistor, old coil, removed as possible culprits.
- Vacuum is pulling at a steady 22 inches of mercury during idle.
- I've played with the timing and idle mixture for hours. Seems to hesitate a little less when timing is set to 21 degrees BTDC and the idle screw is opened more than 1.5 turns from closed position, and the idle rpm is increased to 700+ rpm
Where do I go from here? I first thought I had a fuel delivery problem, then I started looking at the electrical stuff, and everything else mentioned above. Your help is greatly appreciated.