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sprinkles08, ASE Certified Technician
Category: Chrysler
Satisfied Customers: 22534
Experience:  ASE Master & Advanced level certified, Chrysler Master Certified, Trans and Hybrid Specialist
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2005 Pt Cruiser: turbo..the problem its firing on 1 & 4 but no fire

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I have a turbo 2005 Pt Cruiser is the problem its firing on 1 & 4 but no fire on 2 & 3. I replaced the coil, plugs, an plug wires. Has anyone seen this before? The car was running good no problem till a few days ago my wife was driving it an it lost all power an died. At first I got it to start but it was running very rough...but now it will not start at tries but just want run now. It throws a code P0300 & P2305. please help! Note the car has 91,000 on it....

Hello and welcome to JustAnswer!


Do you have a test light?



Customer: replied 6 years ago.
Yes I put a test light on all 4 cylinders only 1 & 4 lite up....2 & 3 did not lite up. I just did a compression test an got 140 psi on 3 cylinders and 148 on the other cylinder. The book say should be 175 - 225 range. I was thinking it could be the timing off......but 1 & 4 firing an 2 & 3 no fire throws me off?
This could go a couple different ways then.

Was the P2305 set before you started any work? Or did it maybe set after the replacement coil was put on or some testing was done?
Customer: replied 6 years ago.
No I got the P0300 & P2035 before I done anything......

The P2305 could be set because of a problem with one of the coil drivers, either a wiring problem between the powertrain control module (PCM) and the coil, or an internally failed driver in the PCM. This would account for the lost spark on two cylinders (one coil).


On the other hand with the lost compression that could be telling us that the cam timing is off. If the cam timing is off because the belt has jumped or a dowel pin on a cam has sheared. If the cam timing is off that will cause the low compression and lack of spark on one coil.


Make sure your compression numbers are reliable. The compression test needs to be done with the throttle open, all plugs out and constant battery voltage. I'm assuming you probably had the plenum off, so you wouldn't need to worry about the throttle. If you did check compression under all of these circumstances and it was low then cam timing is very suspect.

Customer: replied 6 years ago.
No I did one cylinder at a time let me go do it again. Also when you day throttle open do you mean like gas pedal all the way to the floor?
Yes, the throttle should always be wide open when doing a static compression test.
Customer: replied 6 years ago.
Ok just redone compression test got different reading this time.

1- 142psi
2- 135psi
3- 115psi
4- 152psi

Do you think its possible that the time belt has jumped a notch or two? Do you think the low compression on 2 & 3 got so low that the PCM want let it fire? As you can see that 1 & 4 is higher thats why the computer is firing on them an not 2 & 3??? Would low compression keep the computer from firing???

The low compression wouldn't have an affect on the coils firing, but low compression is a sign of a jumped timing belt. If the timing belt has jumped that would also explain a coil not firing.


Try and throw the plugs back in and put everything back together so it can run. Unplug the cam sensor, crank the starter for a good solid ten seconds and see if the engine does end up starting. If it does start with the cam sensor unplugged then you know you have a cam timing problem.

Customer: replied 6 years ago.
The low compression wouldn't have an affect on the coils firing, but low compression is a sign of a jumped timing belt. If the timing belt has jumped that would also explain a coil not firing.

(I agree but why is it firing on 1 & 4?) Could it still be the PCM? Also the timing belt or both? Its kind of odd that both would go at the same time.
The problem could be the PCM, wiring to the coil, or the engine has jumped time. It could be that the PCM has lost a coil driver, one coil driver circuit from the PCM to the coil is open or shorted, or the engine is out of time. It's not uncommon to have one coil firing and one coil not firing when the engine is out of time.
Customer: replied 6 years ago.
I have to go to work I've got just 20 min. to go out the door. Tomorrow I will do the test you stated above an get back to you tomorrow. Its got 91K on it, the belt need changing anyway so I'll probley go ahead a change it. I just wished I knew if the PCM was bad or not....I'll let you know tomorrow....Thank You...

Sounds great. Good luck!


Customer: replied 6 years ago.
Ok I did the test by unpluging the cam sensor......still would not start. It sounds so close to starting but just can not fire up. It trys to hit and will try to run for a second or two when I stop crancking. If its the timing off a notch or two do you think the pistons have hit the vals? When I had the plugs out and was checking compression it turned over real smooth. Also when I unpluged the cam sensor I got the cam sensor that tells me it working.

With the cam sensor unplugged does it bring spark back on all four cylinders?



Customer: replied 6 years ago.
No there was still no fire even with the cam sensor unplugged. Sorry about being late on getting back with you......but I went ahead an took the timing cover off...boy this is a job! Everything is so tight fit an hard to get to.....anyway the time was right on the money. But its got 91K so I'm putting a new belt an water pump on...I was planing on doing that this summer anyway. I think this points to the PCM now. What do you think? Also I read that the reason the compression read so low was because the engine was cold. What should be my next step? After you answer I'll accept answer so you can be paid. Thank you very much for working with me on this....

If there is anything else I should do please let me know. Also where is a good place to get a computer?

Again thank you!


When you remove the timing belt I'd also recommend removing the intake cam sprocket and check the dowel pin that times the cam to the sprocket. This dowel may have sheared, this would cause a cam timing problem but the marks would still line up.


Other than that we're back to a wiring or PCM problem. If you do replace the PCM you can try a parts store and see if they can get a remanufactured unit. Other than that it would need to come from a dealer. Either way once the PCM is installed it will need to be programmed with a scan tool.

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Customer: replied 6 years ago.
Have heard of All Computer Resources they say all thier computers come pre programmed. They use the Vin #. price $325. As far as the wiring all the wires look good no oil or cuts that I can see I've checked all the plugs all looked good too.
They can't do the SKIM programming though. Even if you get a remanufactured one the SKIM programming still has to be done with a dealer scan tool once it's installed in the car, otherwise the engine will start and die.