2000 ZX2 cut off and won't start


ladyinred58
09-09-2007, 09:33 PM
I have a 2000 ZX2 that started giving problems cutting off while driving. At that point it would start back. Had it checked and the diagnosis of a bad oxygen sensor was had. Replaced the o2 sensor and went to test drive the car and it went about a mile and then just cut off and would not start back. The computer was once again tested and it gave a reading of bad camshaft sensor which was replaced but the car still will not start. Have looked through the oil cap to visually check everything is moving and that the timing belt did not break, and everything thing that should be moving is moving. The odd thing it is now doing is it sputters on the compression stroke. Kind of like a small backfire on the intake side. The engine is turning like it should to start but doesnt start.

Any help would seriously be appreciated.

Thanks

carlos80
09-10-2007, 12:31 AM
Check for fuel,spark, and compression. How long has it been since you've replaced the fuel filter,plugs and ran some injector clener through the tank? If you have no tools to check for fuel pressure try to start the vehicle with starting fluid if it starts then you have a fuel system problem or just put your ear by the fuel filler door and turn key on, and listen for the pump to come on. If it doesn't I d check the Fuel Pump Cut-off switch should be in trunk compartment. By the symptom you describe it seems unlikely a fuel pump problem is the cause but it doesn't hurt to check. As far as the 02 or cam sensor causing the stall problem its almost impossible, I'd be looking more at the ignition system or an incorrect timing problem.

Markb873
09-10-2007, 08:32 PM
As far as the 02 or cam sensor causing the stall problem its almost impossible, I'd be looking more at the ignition system or an incorrect timing problem.If the exhaust cam is not advancing/retarding like it should it will trip a cam sensor fault which will cause a no-start, cutoff condition. code p0340 to be exact.

Ladyinred, unplug the cam-sensor. The computer will then run all of it's ignition principles off the crank-sensor and bypass the cam/VCT circuits. If it "corrects" the problem then the problem is most likely a dead VCT solinoid.
FYI, an O2 sensor does absolutly nothing except report to the computer the oxygen content of the exhaust so the computer can adjust the amount of fuel. Both extremes of what the sensor is capable of reporting are not near enough to cause a drivability concern. It mainly controls emmissions and helps fuel mialage a bit.

carlos80
09-12-2007, 07:07 PM
If the exhaust cam is not advancing/retarding like it should it will trip a cam sensor fault which will cause a no-start, cutoff condition. code p0340 to be exact.

Ladyinred, unplug the cam-sensor. The computer will then run all of it's ignition principles off the crank-sensor and bypass the cam/VCT circuits. If it "corrects" the problem then the problem is most likely a dead VCT solinoid.
FYI, an O2 sensor does absolutly nothing except report to the computer the oxygen content of the exhaust so the computer can adjust the amount of fuel. Both extremes of what the sensor is capable of reporting are not near enough to cause a drivability concern. It mainly controls emmissions and helps fuel mialage a bit.

P0340 could in no way cause a no-start condition or cut-off condition, a lack of power condition would be more likely. VCT kicks in at higher RPMs(not idle or start), not to mention that spark is controlled by nothing but crank sensor input, the CAM sensor is used for Sequential Fuel Injection(SFI),and VCT in this case, not like in the old days where injection as well as spark was done through crank sensor input only. I've worked on vehicles that drove in with the code you mentioned, all this causes is injection to be synchronized with spark(eliminates SFI), it would be bad programing to cause a vehicle not to start because of a cam sensor fault when all you need is to know, to spark and inject fuel is when the cyl is close to TDC.

Markb873
09-13-2007, 06:49 PM
We are not talking about bad programming! We are talking about a mechanical failure! I've been there before, P0340 can be accompanied by a no-start/cutoff. Say for instance, the engine is running at a speed faster then idle and the VCT solinoid craps out. Depending on what the engine was doing at the time the exhaust cam can be stuck anywhere between +/- 30 degrees. Mine crapped out, they don't just magically return to center. The car stalled. Then it wouldn't start. Suprise! It threw P0340. Replaced the solinoid and it went away.

You are right that the VCT doesn't move at idle but what you are missing is that a VCT solinoid can and will fail when the engine is moving faster then idle and will get stuck at a position that doesn't make the engine happy at idle. This will cause a no start, and a cutoff at lower speeds.

P0340 has nothing to do with the sensor it involves the circuit. The computer is receiving input from the cam sensor that is measuring a cam positioned anywhere in a 60 degree range from where it should be. When these numbers don't match, the computer assumes the crank is correct and throws the code.

Check this address
http://www.obd-codes.com/trouble_codes/generic/p0340-camshaft-position-sensor-circuit-malfunction.php

carlos80
09-14-2007, 07:24 PM
You are correct. Should the cam be stuck that retarded it would cause a stall, no start condition.
However P0340 could indicate a problem with the sensor, not just the wiring(circuit) like you said. Just read the link you posted carefully it tells you right there. I've fixed plenty of FORD s with this code that turned out to be a faulty/damaged sensor. You were also incorrect about the ignition system, on this particular vehicle, using the cam sensor as any type of input, it runs "its principles" strictly off the crank sensor.

Ladyinred, unplug the cam-sensor. The computer will then run all of it's ignition principles off the crank-sensor and bypass the cam/VCT circuits. If it "corrects" the problem then the problem is most likely a dead VCT solinoid.


I'm aware of only COP systems using the Cam sensor as an input for the ignition system, and even then failure of the cam sensor causes the system to rely on crank sensor input, for both fuel injection timing and spark. Like a said before a faulty CAM sensor would not cause a stall, no-start problem. She replaced it assuming it was bad. I simply stated that a bad sensor would not cause the stall, which is true, if she would've known this before she wouldn't have replaced it. DTC's are not always created by the circuit-sensor they refer to, Just like in your case, it was still not the sensor that caused the no start problem it was the solenoid and this is usually accompanied by other codes.

Markb873
09-14-2007, 09:42 PM
There is a relationship between the cam sensor and ignition. By disabling the circut, it makes the difference of the engine actually running or not in this case. Anyways, The fuel system still delivers fuel, with the sensor plugged in or not. wether SFI or old fashoned TBI style. With a stuck camshaft, it makes no difference wether or not it's pugged in, as the orientation never changes. Ignition is the only thing that changes. The bottom line is although it's not listed as being part of the same system it's still an indirect relationship. Indirect relationships are still relationships. Bad valve timing affects ignition as well as fuel mileage, driveability,etc. If there is a malfunction in one it will effect others. The sensor tells where the camshaft is, when the camshaft is somewhere else, the engine odviously struggles to fire the cylinders correctly.

I gave a scenerio of what could be the problem, with this cam code present. I have had the same symptoms happen to me. I gave a way to test the theore. I am assuming that the code is a solo code, as was mine, espescially sence no others were indicated. If it's not the case then at least It eliminates one more thing.

ladyinred58
09-16-2007, 05:51 PM
I have tried unplugging the cam sensor and the car still will not start. The starter turners and on the compression stroke it will backfire through the intake. If this were an older car I would swear it has jumped time. It is getting fuel so the fuel switch has not tripped and cut off the fuel. It has spark. I am at the hair pulling out stage with this car.

Does anyone have any more suggestions that I can try?

Thanks

Markb873
09-16-2007, 07:29 PM
The coil pack does fire on the exhaust as well as the power. It would make sense that the valve timing is the culprit. There could be a spart right before the intake valves close.

So did the timing checked out okay? I had an old Toyota Celica that had the timing off to cause, at most, backfire. However this was in the 80's.

carlos80
09-20-2007, 08:00 PM
Compression test.

ladyinred58
09-22-2007, 11:39 AM
I have now replaced the crank position sensor and the car still will not start. It only will backfire through the intake when trying to start it. I am beginning to think a good case of dynamite would solve the problem.

Ugh

Thanks

blakley
10-01-2009, 12:19 PM
I have had prob like this for a year. can,t figure it out. My problem is when weather is cold. I found that plugs are being flooded at cold start, I change plugs and it starts. If it backfires internally you have fuel and spark you are flooding. I have replaced just about everything. Can,t figure it out, but i can start it even when cold.

Davescort97
10-02-2009, 11:21 AM
Welcome to AF!

Thanks for posting. This thread is over 2 years old and it is unlikely that you will get any response from it. If a thread is over 3 months old it would be more productive to start a new thread concerning your problem. Thanks. ~Dave~

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