Our rebuilt fuel injection components are the highest quality available and replace no longer available parts. Your 914 fuel injection can again operate as it should for snappy performance, great gas mileage, and long engine life. The manifold pressure sensor is notorious for diaphragm failure resulting in a rich mixture black sooty exhaust and a poor warm idle. please evacuate to check this part. if it will not hold vacuum it is bad. rebuilt by the leading Bosch injection company in the nation you can be assured of a perfect calibration. purchase the 037 European sensor for extra top end performance along with the factory temperature sensor resistor. There is a core charge, which is refundable upon receiving your rebuildable part.