Perhaps one of the least understood components on the E30 M20 is the EVAP Fuel tank breather valve. If the valve is stuck open or if the hose has a tear, it will cause a significant vacuum leak. The green hose connects to a brass barb on the underside of the throttle body. It...
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So you’ve heard that you should change the timing belt on an M20 every 50k miles or 4 years (whichever comes first), because in case of failure the valves will hit the pistons, rocker arms will break, and you’ll be looking at a top end rebuild or a new engine. But what many people,...
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If you’ve purchased an aftermarket underpanel for your E30, you’ve probably realized it doesnt not come with sound insulation. This sound insulation is called Jute. OEM PN 51488229734 provides for just enough insulation to do one under panel.   The insulation has one sticky side and one cloth side; doubling the layers will make...
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In the vast majority of cases, vacuum leaks are to blame for poor or inconsistent idle issues on M20 engines found in E30’s. Vacuum leaks basically mean air that is entering the engine where the air flow meter has not had a chance to meter it. Unmetered air, is unexpected air, and as such...
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This is an excerpt from the factory E30 repair manual instructing how to mechanically and electrically test the ICV (idle control valve) for an M20 engine.
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In the world of alternators the one used on most all E30’s is quite simple and straight forward. The Bosch alternators are a a two post design, with D+ and B+ terminals. B+ (also called 30) is the larger of the two and routes through the starter, then the battery junction box and finally...
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Near most idle issues are derived from unmetered air entering the intake past the AFM (Airflow Meter). Simplified, it means you have a hole in one of your connections, gasket matting surfaces or intake related hoses. Un-metered air is a fancy way of saying that you have additional air entering your system that the...
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The E30 was built with with a vent-free fuel cap, and it was for a reason. If you’ve ever placed your finger on the end of a straw with liquid in it, you will have found that the liquid doesn’t fall out the bottom. Similarly, the 80’s fuel system is designed with this pressure...
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Alpine CM5905, CM5907 Bulb: T1-1/4 12v 75ma (4mm) If you follow this video along until 3:12, it will be clear how to remove the bulb holder, then all you need to do is unsolder and resolder the new bulbs. Pioneer KE-91ZBM, KE-92ZBM Bulb: T1 8v 60ma (3mm)
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Other than a coolant leak around the heater core, most wet carpets are a byproduct of the water drains being clogged. The water has nowhere to drain and backs up and flows into where it shouldn’t; either your interior or settles and causes moisture/rust where it shouldn’t. The good news is that cleaning the...
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