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.
Injector Circuit
1991 Mercury Cougar LS, 3.8 4SECTION Injector Circuit
- Disconnect all injector harness connectors. Using digital ohmmeter, check resistance across terminals of each injector. See appropriate injector resistance table.
- On models without Sequential Electronic Fuel Injection (SEFI), disconnect injector bank harness connector, check resistance of injector bank. See INJECTOR BANK RESISTANCE . Injectors on SEFI models have each individual injector wired to the ECA. Repair wiring or replace any injector circuit not within specification.
INDIVIDUAL INJECTOR RESISTANCE (1)
| Engine | Ohms | ||
|---|---|---|---|
| All Models | 13.0-16.0 | ||
|
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INJECTOR BANK RESISTANCE
| Engine | Ohms |
|---|---|
| 2.3L HSC | 6.0-8.0 |
| 2.3L OHC | 7.0-9.5 |
| 3.0L | 5.0-6.5 |
RENDER: 1.0x
NO RELATED
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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.