Letters: Faulty ignition coil could cause start-up problems

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Q: I own a 1988 Dodge Aries. It starts and runs good as long as it’s not raining. If it’s raining, it won’t start. I’ve replaced the distributor cap, distributor rotor, spark plugs and spark plug wires. What else could it be? – Dan, Chicago

A: It could be a faulty ignition coil. The ignition coil could have an insulation problem causing it to act up in wet weather. Also, make sure that the ignition coil has adequate voltage on the primary circuit when cranking the engine. Any poor or corroded electrical connections in the primary circuit will reduce the coil’s ability to deliver the necessary high voltage on the secondary circuit to jump the air gap at the spark plugs.

Q: About how much money should it cost to replace the timing belt in my 1995 Ford Ranger two-wheel drive with a 2.3-liter engine? I was quoted about $800 from a shop near my work and I think that’s kind of high. What do you think? – Ray, Elk Grove Village

A: That price quote seems kind of high to me, too. But that depends on what’s included in that price quote. The timing belt itself costs around $30 to $50, and the labor time to replace it is about 4.5 hours. So, if the shop’s labor rate was $100 per hour, it should cost closer to $500 for that repair.

Q: The engine in my 2000 Chevrolet Malibu is using a lot more fuel than usual. My neighbor who tinkers with cars said it’s probably the oxygen sensor, so we replaced it. We also gave the engine a complete tune-up. These repairs didn’t help at all. The car is still using too much gas. What could be wrong? – Stan, Aurora

A: Your car could have a leaky fuel pressure regulator or fuel injector. A fuel pressure gauge will need to be installed to check fuel pressure with the engine running and with the engine off. Fuel pressure should be within specifications, and it shouldn’t drop off once the engine is turned off. Fuel pressure that drops once the engine is turned off can be due to leaky fuel injectors or a leaky fuel pressure regulator.

To check the fuel pressure regulator, turn the engine off and remove the vacuum hose connected to the pressure regulator. If you find the presence of fuel in the fuel pressure regulator’s vacuum hose, the pressure regulator will need to be replaced. If your fuel pressure tests don’t reveal any trouble, check the engine for any vacuum leaks or problems with the mass airflow sensor.

Q: I was told that the engine in my 1994 Dodge Intrepid had a lot of carbon in it and it needed to be cleaned. A friend of mine suggested a product called Sea Foam. Do you know anything about this product? Does it work or will my engine need to be taken apart to clean it? – Art, Glenview

A: I’ve used Sea Foam and products like it. It’s important to follow the directions when using these products. Also, if you do plan to use this product, perform this in a well-ventilated area as there will be a lot of smoke coming out the tailpipe. Operating the vehicle regularly for periods of time at highway speeds can help prevent the recurrence of carbon buildup.

Questions for Ira Siegel? Call the Auto Advisor Hotline at (708) 633-6839 or e-mail ira.siegel.is@gmail.com. Siegel is an automotive instructor and an automotive service excellence-certified master auto technician.