Why won't it start?

My 87 was running ok until I pulled the connector of the Idle stepper motor while it was running. It hissed stalled and won't restart. There is fuel, spark and it cranks just fine.

Kenny

In response to my own post. How far out should the stepper motor be protruding? I pulled the motor off the TB and it is out about an inch or so. My thought is when I pulled the connector off and put it back on it sent some signal to the ECU that won't allow it to start.

To dump all the "learned" memory in the ECU, disconnect a battery cable for about 15 minutes, then reconnect. That will eliminate the situation you are worried about.

Earlier I disconnected the battery for a bout 2-3 minutes and when I reconnected and turned on the ingnition the O2 sensor and fuel pump relays started chattering. I will try the 15 minute thing now. Also when those two relays were chattering the idle stepper motor was vibrating at the same rate. I had it out, connected and I was holding it. The book says that I should have 50 ohms across the two different set of leads and I am getting 553 and 549 ohms.

Kenny

The 15 minutes did not work. The relays aren't chattering anymore but there is a intermitten thunk comming from the fuel pump. Is it possible that my fuel pump just went bad. There is fuel to the rail. What if the pressure is not high enough at the rail? Would that be an issue?

Kenny

Ok I changed the Idle stepper motor and still no start. It just cranks. Any other thoughts.

Kenny

Still cranking but no starting

Could I have screwed up the ECU by unplugging the connector with the ignition on? I can get a new one but don't want to if there could be something else to try.

Kenny