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From "Dennis M. Boyle"
Sent Saturday, June 24, 2006 0:44 am
To Dennis Boyle
Cc
Bcc
Subject Intermittent No Start Problem
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I have an intermittent no-start problem with my 1991 240 wagon. Engine is the normally-aspirated inline four cylinder; B230F. Sometimes, when trying to start the engine, it will crank but not start. After disconnecting the coil and reconnecting another coil, it will start without fail. I have repeated this over and over again and found the same result. All I have to do is disconnect and swap the coil with another, and the engine starts. It doesn't seem to matter if the coil is new or used - what seems to make it start is disconnecting the coil that it failed to start with and reconnecting another coil. Once it fails to start with that coil, I can reinstall the first one that previously yielded a no-start condition and have the engine start. I am completely baffled.
So far, I have installed a new Bosch coil and ignition module. I have tested the fuel pump relay and found that it works properly. I have also tested fuel supply at the rail and found that it has fuel pressure. Today I removed the distributor cap and examined it, the rotor, and the distributor and found no apparent malfunctions or defects. The cap, rotor, and plug wires are all OEM parts and fairly new; I'd say less than two years old. I just installed new NGK plugs about two days ago, and they are gapped correctly.
I tried troubleshooting with the aid of a timing light just to show when I am getting spark. When the no-start condition exists and I have the timing light connected on to the coil-to-distributor wire or to the #1 plug wire on I find that I get spark from the coil about every fourth crank. When doing the same test after disconnecting and changing the coil (when the engine does start), I find that the coil is discharging as rapidly as the engine cycles, which is what it should do under normal operating conditions.This condition usually happens when the outsie air temp and humidity are high or after the engine has been operating for at least ten minutes,turned off and then a re-start is attempted. The first start in the morning is normal and the engine performance after starting is normal.
Has anyone had a similar problem?
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