Have to disconnect/reconnect battery to start car,immobilizer problem?

hufilm99 · Post by **hufilm99** » 08 Jul 2016, 00:10

Hey guys and gals I have a real problem I can't seem to figure out. My car won't start constantly. If I let the car sit for a period of time, say over night, it will start right up. When I go to start it a second time if not much time has passed the car won't start. The car will crank but won't turn over. It seems like the car isn't getting fuel pressure so I check the fuel relay and fuel pump and they seem to be working fine. Also, the car has a new battery so no problem there. Today I just discovered a trick to start the car that might point towards the problem. If I disconnect the battery for about a minute then reconnect the car starts every time. Does this make sense to anyone? I'm thinking now that it's some problem with the immobilizer but I'm not getting any codes on the dash to tell me this is the problem. Has this happened to anyone else? Sorry for the long post. Look forward to hearing from the group.

B

Post by **abscate** » 08 Jul 2016, 08:27

An immobiliser trigger does not set an engine code. You might have a engine coolant temperature (ECT) sensor issue that is dumping excess fuel into the engine for a start - there is info here in the VRD on testing that unit for correct resistance.

Diagnosing by symptom is rarely successful on these cars - you have to break out a systematic approach to evaluating spark, fuel, air, timing and compression and find out which one(s) are missing

hufilm99 · Post by **hufilm99** » 08 Jul 2016, 11:27

I did a number of checks and I know it's a fuel issue. When testing the car from a bad start, I noticed that the engine wasn't getting any fuel pressure. I swapped the fuel pump relay and fuel pump but discover the problem is still there. Basically the car will only start after sitting for a long time or disconnecting the batter resetting a sensor in the car. The car will reliably start if you detach the battery cable. So there has to be a system in the car that is preventing fuel from getting to the engine once the system "sets" its self if that makes sense. I've been reading through a number of forums but I can't seem to find anyone with this same problem. Am convinced it's something with the anti theft system but I'm not sure where to look first.

Post by **Ozark Lee** » 08 Jul 2016, 12:57

The immobilizer on your car typically will let the car start but about 1 second later it will die. I believe it does that by killing the ignition but not the fuel.

Have you tried installing a jumper wire in place of the fuel pump relay? A wire between the socket positions associated with pins 15 and 87 on the relay should power the fuel pump anytime the ignition switch is on and it is a very good diagnostic tool.

Beyond that you will really need to get a scan with VIDA and DICE to see what is actually happening.

...Lee

Post by **abscate** » 08 Jul 2016, 18:16

Me7 cuts ignition, so you have to run the fuel system diagnostic tree