The car has a turbo engine. It has been idling very rough. The RPMs would erratically increase and decrease. I had a new head gasket installed. I replaced the spark plugs with new ones as well as the spark plug wires, rotor and cap. It sometimes feels as if the car would stall. I had the vacuum lines checked as well. Do you have any suggestions?
Hi there, thanks for writing in about your 1990 Volvo 740. The symptoms sound similar to a vehicle suffering from a boost leak or electronic air metering and fuel delivery faults. The vehicles do not have the new OBD-II ports, but our technicians are equipped with factory service instructions to retrieve trouble codes. Avoid an unsafe situation by continuing to drive. To have this resolved, consider having a certified mechanic, such as one from YourMechanic, inspect the rough idling problem in order to have this properly fixed.
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