Join Date: Sep 2016
Location: Big Island, Hawaii
Strange starting issue on 850 m/t
Hi, I am new to this forum and have learned a lot from reading many threads. I have a problem that I have researched a lot and can't seems to find the right answer. My problem is with a '95 850 GLT with a manual transmission. When the car is overnight cold (in Hawaii that is never below 60F), and occasionally when hot after sitting for 20 minutes or so, it will crank until the battery goes down, but not start. Once every few days it will start right up hot or cold. If I push start the car in first or reverse it will start ever time on the first kick.
Fortunately I live on a hill and getting going in the morning is never an issue, but on the rare occasion I am in a level parking lot and it won't start, I get stuck and it just won't start until it is push started. What I have done is replace battery and suppky connections, the engine coolant temperature sensor, the crank sensor, the cam sensor, the coil and ignition module, the plugs, plug wires, and the distributor cap and rotor. Nothing helped. Once started the car runs great and never misses a stroke. It revs up to red-line with perfection and idles perfect with the a/c on or off. I have also recently serviced and checked the operation and electrical resistance and operating voltages of the throttle position sensor and idle air bypass system. I have also tested the fuel pressures and it is to spec with no leaks even over night. The fuel pump was recently serviced and works as expected. I don't have any obvious fuel delivery issues.
Here is what I suspect is the problem. There is a obviously relay somewhere that cuts out power to the accessories when the ignition is turned to the start position and also controls an alternate path for the ignition system power when the starter motor operates. No problems found. No engine codes are set (it is OBD1).
I suspect that a relay is temperature sensitive and either sticky or just plain a poor conductor on the contact points in the system. Could someone please tell me which relay controls this function and where it is located? I have looked at the wiring diagrams I could find online, but so far none show the complete paths for the ignition switch wiring. I figured that it must be a relay problem because the ignition works flawlessly when the key is in the run position. Is this part of an alarm relay, overload relay or injector relay function? Is there an ignition amplifier in this system? I am running out of ideas here. Any advice or feedback would be greatly appreciated.
Thank you, Peter