

| Subject: | Re: Having an annoying problem with my 85 GL. |
| From: | Mark A. Williamson |
| Date: | Mon, 16 Nov 1998 14:55:05 -0700 |
I once experienced something similar with my 88 Wolfsburg Weekender. For me, it turned out that the catalytic converter has become "clogged" due to inadequate combustion of fuel. This led to the inability of the cylinders to vent properly after the combustion cycle and the on-board computer sensed a pressure high enough to make it think that the cylinders were "full" and no fuel was injected for the next combustion cycle. The engine would not completely stall however, because the next cycle fuel WOULD be injected and combust- to a point. When, ultimately, back pressure could not be vented adequately the engine "died." I replaced the catalytic converter and the problem was gone and has not returned. The fouled catalytic was (apparently) caused by a solenoid that crapped out (intermittently), leading to unburned fuel gunking up the catalytic converter. The ignition problem was corrected shortly before the catalytic converter problem arose, as I though that the ignition system concern would cure the "total" problem. It turned out to be only half the problem. Summary/Suggestion(s): Check that fire is being delivered to the spark plugs (correct frequency/timing and voltage). If correct, the back-pressure may be building up and causing the "brain" to think the cylinders are full of fuel. Then, the catalytic converter may be fouled. I am not sure if simply check the compression on a cylinder will clarify this potential condition, as the compression test will not distinguish between fuel and burnt fuel. Mark Williamson Denver, CO 88 Wolfsburg Weekender
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