I am called to a shop this day for a problem with a 1997 Chrysler Sebring with a 2.5 liter V-6 motor. The shop owner explains to me that this vehicle has been all over the place. Lots of replacement parts. It runs real poor. So poor that the catalytic converter glows red after only a few moments of operation. The shop owner has had enough of this car. He has spent a considerable amount of time and resources on it. The vehicle sets Cam/Crank error codes as well. It has had multiple crank sensors. After listening to the shop owner and hearing the vehicle run. I am pretty sure we have some cam and crank relationship issue. I have been down the road with these vehicles before. There are many things that can go wrong from improper timing belt replacement, broken camshaft dowel pins, worn crankshaft gears, wrong or damaged flywheels, wrong year PCM with wrong flywheel with wrong camshaft sprocket, etc. The first thing I do is scope camshaft sensor and crankshaft sensor to look at the signals and more importantly the relationship between the two.
A couple of days later he calls me. He goes on to tell me that the vehicles crankshaft sensor he removed had obvious contact damage. The new OE sensor fixed the car and the car runs well. I was happy for him.
The next Chrysler is a 1995 Chrysler Cirrus with a 2.5 liter V-6 motor. It is a crank no start. Also, the shop owner says it has no scantool communication. I crank the car over. It has a nice even cranking sound. I hook up my scantool and I indeed have communication. This is one of those vehicles that have the familiar OBD2 data link connector but are really not true blue OBD2. We used to call these cars OBD one and a half on the techline. I check certain key parameters on the scanner such as map voltage, vehicle theft status, and cranking inj pulse. All look good. I check spark quality and scope ASD (Automatic Shutdown) relay voltage and injector pulse right at an injector. I have great spark, good ASD voltage cranking, and proper injector pattern. What gives? I spritz a little carb spray into the throttle body and car cranks starts and stalls. I break out the propane and can run the car. Ok, I know I have no fuel. Hooking a fuel pressure gauge up on this vehicle is a pain in the a$#. So, I use ATM (Actuator Test Mode) to actuate the fuel pump relay. I hear the relay click but no fuel pump operation. I remove the relay to jump out and look at the pattern with my low amp probe.