So i have a 98 cavalier with 150,000 miles. It just in the last week had a hard time starting it. I can get it started occasionally and keep it running if i stay on the throttle. If i let off it will eventually die and be hard to start again. I tested the codes and it came up with p0335 (crankshaft positioning sensor A circuit malfunction and p0342 camshaft position sensor A bank 1 circuit low input). The CKP was $7 so i went ahead and replaced that, i am reluctant to put the camshaft sensor on because after i put the CKP sensor on and both codes were still popping up, and the camshaft sensor is $70. It seems like it could be an issue with the timing chain but it doesn't knock or tick. Additionally i would have thought that if the chain was stretched it would have happened over time and would have had some knock or tick or something. can anyone help or give me some advise or direction please.

Additionally, after replacing the crankshaft sensor i cleared the codes and had the car running, it idled great for about 3 minutes and then immediately shut down, both codes read again.

 

timing chain tensioner?

 

I've replaced the timing chain and timing chain tensioner, i have the dots lined up and everything, the chain was loose so i think the chain did need to be replaced, however now the car wont even start. Now the car is not even getting spark. I no longer have a code reader and the car is not running so bringing it to autozone to test whatever code the car is putting out now is simply not an option. The codes that the car was throwing initially were crank position sensor and camshaft position sensor. The car cranks fine but just will not start at all, i unhooked the battery for ~5 minutes hoping that it would clear any codes. I took the ignition control modulator to autozone and had them test it to see if it was good, they said it failed the test. My brother has a '99 cavalier that has the same ignition control modulator, we swapped them and it still would not work, we even put the supposedly bad modulator on my brothers car and it started right up and ran with no issues. I've been searching for any advise on the internet and have pretty much noticed that there seemed to be alot of issues with the ignition switch on this car. The fuel pump does kick on when i turn the key. I hear a buzzing sound when i turn the key on that did not happen before all these problems started. I dont have hundreds or potentially thousands of dollars to take it to a dealership for them to diagnose/treat the issue. Does anyone have some advise to help me out please?

 

I think those two sensors need to work in conjunction to tell the computer the exact position of the engine. This is probably why it isn't sending spark. I think you should change the cam sensor, clear the codes and try again.

Don't know why both would fail though..?

 

what you have is a faulty connection in the wiring that goes to both, the crank and cam sensors . you'll have to unwrap the insulation from that section of the harness and check the signal wire there