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.
1988 BMW 535is AutomaticFACTORY OEM SERVICE PROCEDURE
Valve Does Not Open
- Remove valve, leaving fuel lines connected. Energize fuel pump. Supply battery voltage to cold start valve with jumper wire and ensure valve is properly grounded. Cold start valve should deliver fuel. If not, replace valve.
- If valve functions, check spray pattern and flow rate. Pull plug off valve and connect volt/ohmmeter between wires of plug. Start engine. Meter should read battery voltage while cranking engine. If not, trace circuit and repair wiring. See WIRING DIAGRAMS at end of this article. Check thermotimer as described in TEST 12 and replace if necessary.
Factory Service Tools
Use the Manual With the Right Hardware
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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.