remote start cranks, doesn’t start, key works

I have an 1989 BMW 325i that I installed a Commando FM-870 in about a year ago. The remote starter has worked fine (with tachometer checking, wire going to the coil) until recently. I have tried to re-learn the RPM. I tried changing the check level. I have tried using other starting methods (voltage and timer checking) and increasing the cranking time up to 4 seconds, and I still can't get it to start. I tried turning off the A/C (which is the main reason I want to remote start) just to check if that would make any difference, but it didn't. The odd thing is that when I use the key, it starts up no problem...probably less than 1 second. I'm at a loss as to why it won't start even if I have it cranking for longer than it ever takes me to start it when using the key. I was also wondering if there should be some other wire I have hooked up or something for the voltage or timer checking. I've checked the manual and can only find a mention of connecting a wire for a tach. If anybody could suggest some things that I might check that'd be great. I like to get my A/C going before I get in a car that's been sitting in 100+ weather all day!

If the vehicle starts fine with the key, but not the remote start, check your ignition feed fuses. If you aren't getting an ignition feed, then you won't be allowing spark or fuel, but the starter will crank to its preset time limit regardless. Get a volt meter and check all the outputs during remote start and make sure you are seeing voltage on all of the spliced ignition wires. It could be a fuse also depending how your system was wired. How did you make the connections to the RS harness?

Run second ign. output from R/S to ign. purple, that car will have a coil, use the - on coil to feed the tach.

Voltage checking is done through the power supply wires that go to the r/s brain -- during the cranking, the engine starter draws juice from the battery and drops the voltage during this process, and then, when the engine is successfully running, the voltage jumps back up to 12.44 volts (or so) and the power meter in the r/s brain knows it's started.The search function is your friend.

awdeclipse wrote: If the vehicle starts fine with the key, but not the remote start, check your ignition feed fuses. If you aren't getting an ignition feed, then you won't be allowing spark or fuel, but the starter will crank to its preset time limit regardless. Get a volt meter and check all the outputs during remote start and make sure you are seeing voltage on all of the spliced ignition wires. It could be a fuse also depending how your system was wired. How did you make the connections to the RS harness?

Yeah, I seemed to have had a week long brain fart ;). I was thinking there was only one wire that controlled the starting. If that were true it'd be cranking the starter whenever I drove it, heh. I used taps and a butt connectors. I'd be willing to bet there's a bad connection there. I haven't gotten around to checking it because the weather is so hot :-\. Thanks for the help!