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.
1990 Chevrolet Suburban R2500, 5.7 K, Automatic, 3L80-HD/M40FACTORY OEM SERVICE PROCEDURE
Distributor Pick-Up Coil Short & Resistance Checks
- Disconnect pick-up coil leads from HEI/EST module terminals "N" and "P". Set ohmmeter to middle scale and connect one lead to either pick-up coil lead and the other lead to distributor housing. See Fig 1. Flex pick-up coil leads by hand to check for intermittent shorts to ground. Reading should be infinity at all times. If not, replace pick-up coil.
- Connect ohmmeter between both pick-up coil leads. Check for intermittent opens by flexing wires and connectors. Resistance should be 500-1500 ohms. If not, replace pick-up coil.
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.
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