1997 Plymouth Breeze Vehicle will not start

23268901

MEMBER
1997 PLYMOUTH BREEZE
4 CYL
FWD
AUTOMATIC
140,000 MILES

HI
I am working on a 97 plymouth breeze with the 2.0L engine. The car will crank over but will not fire. I have 50lbs of fuel pressure but no spark at the coil. The code that the computer stored is a P0340 no signal from the cam sensor. I checked for the 8 volt power supply to sensor and got 8.82v. When I ohmed the signal wire I got.1 ohm which mitchell on demand says is good. I replaced the cam sensor and the computer still throws the same code. According to TSB (18-24-97) on mitchell on demand, the computer will store the code of the opposite sensor, (example the crank sensor is bad but will put out enough signal and say that the cam sensor is the problem). After I read this TSB I checked for voltage and signal wire resistance at the crank sensor which were whithin specs and replaced the crank sensor too. It still does not spark and still throws the p0340 code. I also changed the asd relay and checked for supply and control voltage at the relay and they were good. Is it time to start tearing the front of the motor apart to check the timing belt? Any help would be greatly apprecited.

1 Reply

CARADIODOC

MECHANIC
33,754 POSTS

Even though it's the wrong code for this problem, you might want to check for a sheared off dowel pin between the camshaft and sprocket. The sprocket turns a little which causes loss of sync between the two sensors. That is interpreted as a jumped timing belt. One tooth off should set the fault code "cam and crank signals out of sync", and turn on the "Check Engine" light. Two teeth off and the computer shuts the engine down. Three teeth and valves hit the pistons.

When this problem occurs, if you measure the supply voltage to the ignition coil or fuel pump or alternator field, you will find battery voltage for two seconds after you turn on the ignition switch, then it will go away. It should show up again during engine rotation, (cranking or running). The voltage comes from the Automatic Shutdown (ASD) relay when the engine computer gets the pulses from the cam sensor. The computer won't turn the relay back on when it detects the out-of-sync condition.

Caradiodoc