QuestionQUESTION: When car has been running short time (15 to 20 minutes), shut off for 1-2 hours, cranks but won't start. Have been told the engine seems to be flooding after shut-off. Has been tuned up 2 years ago at 100,000 miles and this helped, but didn't solve the problem. Last week, after running rough and wouldn't start (cranked, but wouldn't start), had a tune up this week at 108,000 miles. Mazda dealer said plugs were fouled and electrical arcing in the distributor cap. Tune-up on Sept. 30, 2008 included new plugs, new distributor cap and rotor and new wire set for plugs. After tune-up, was running rough and with a little vibration at idle, and some chugging/hesitation during acceleration. But, big problem was 2 days later, on October 2, car was parked all day at work, driven about 10 minutes to a meeting at 7:00 p.m., and then wouldn't start (cranked, but wouldn't start) at about 8:30 p.m. Dealer had said to keep cranking and never to push gas pedal all the way to the floor (as I had done over the past 2 years at time to get started). So, after cranking didn't work, pushed it manually in a parking lot and popped the clutch and it started. Car is 1985 RX-7, fuel-injected, GSL-SE. So,it seems this 2nd tune-up a couple of days ago is not going to solve the starting problem. Another dealer I had called before this last tune-up said to check compression, but it seems that gas is getting into the engine and flooding it so it won't start after being driven a short distance. HELP. THANKS. MIKE
ANSWER: Fuel flooding is a common no start fault. Excessive fuel can wash the APEX seals especially on an older model causing them to contract reducing the compression. It is pronounced when this occurs because the motor sounds light, that is to say more like the starter motor alone, like it is free spinning as opposed to the loping sound that is common with the compression of each rotor.
Excess fuel can be caused by several things. Air flow restriction (intake and exhaust). Dirty injectors (dirty injectors can cause droplets of fuel instead of a fine spray). These are most common.
Your description of the issue has me wavering a bit on what direction to head in first. You may have overlapping issues.
Fuel flooding and compression loss, compression loss from wear and tare or from fuel flooding.
By depressing the accelerator to the floor you cut the fuel injectors off and introduce pure air, this is a flooded car remedy which seems to have worked for you before which indicates you have a flood issue.
By push starting it you created a forced compression situation, a load as opposed to mere spinning by starter which indicates compression loss.
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QUESTION: Thanks for answer. Very helpful. Mazda dealer thinks one of the 2 coils is failing, which results in losing spark in the trailing 2 cylinders and flooding those 2 cylinders. Then, fuel from the trailing 2 cylinders gets pushed into the 2 cylinders, flooding them too. What do you think? Thanks again. MIKE
AnswerLogical, the spark plugs will tell the tale by looking at them, they will be wet and black if they are not firing. Ignition improvements would include the coils, wires, plugs, ignition condensor, cap and rotor. After market coils run about $50 each. (Standard Ignition p/n UF-6). A set of ignition wires are also cheap ($35). Get NGK if you can find them.
It may be trial and error swapping parts but considering the age and miles it should be viewed as preventive maintenance.
