Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1976 Ford Bronco Automatic TransFACTORY OEM SERVICE PROCEDURE
DECEL Throttle Modulator: Adjustment
NOTE:
This adjustment is to be performed when replacing components found defective during testing sequence.
- With engine at normal operating temperature and transmission in Neutral, adjust carburetor to specified curb idle speed. On automatic transmission vehicles, this will be set to 100 RPM higher than specified curb idle speed (as with transmission in Drive), although transmission will remain in Neutral. This is to keep minimum load on engine.
- Disconnect vacuum hose from throttle modulator and plug hose. Connect manifold vacuum source to diaphragm. Allow one minute for engine speed to stabilize. If engine speed is within specifications, the modulator is properly set. Go to step 5.
- If RPM was not within specification, adjust throttle modulator by loosening lock nut and turning until speed is within limits. Retighten lock nut.NOTE: On Carter 1-barrel carburetors, avoid damage to diaphragm by holding diaphragm shaft with 1/4" wrench while turning adjusting screw with 3/8" wrench.
- Detach manifold vacuum hose from modulator and allow engine to return to idle condition. Repeat procedure from step 2 as required until proper function occurs.
- Disconnect manifold vacuum hose from modulator and allow engine to return to normal idle. Remove plug from original hose and reconnect it to throttle modulator fitting.
- On automatic transmission vehicles, reset idle to specifications with transmission in Drive. On all vehicles, stop engine. Install air cleaner assembly.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.