My 1985 190E shows all the signs of a bad temp sensor. That is, virtually no acceleration after cold start and bogging under wide open throttle even when hot. After two sensors and repairing the wiring to the sensor, I still have the problem. Fuel pressure (system and control) are both within specification, and I find no RPM drops when using the spray bottle intake air leak tests. Compression is middle range. Idle mixture has been set hot to about 7.2mA. Here are the questions:
1. Is 4.9 volts from the computer (vs 5.0) enough drop to create this issue?
2. By installing a manually variable resistor, and forcing the EHA to extremes, that is showing it > 2500 ohms and <50ohms from the sensor I get an improvement in performance for a couple of days. Is this a happy accident, or am I doing something to the EHA or fuel distributor that shows where the problem really lies?
3. Bypassing the sensor with a jumper wire gives me a 1500 - 1900 rpm neutral idle, a stumble from dead stop in gear, 41+mA at the EHA, and wonderful top end performance, which would seem to me to discount the sticking valve problem posted earlier. Am I seeing this correctly as indicating a computer problem, or is there another test I can perform to rule out computer perofrmance?