[lotharamc]

I just rebuilt the 2.7 in my03 Sebring with a five speed. It turns over fine but does not fire. I've tried every sensor and wire with no luck, all test ok. I have spark as tested with a plug out and grounded. I have fuel, I've been trying everything under the sun, and because the injectors are firing but not running, the gas has seeped past the rings so the oil smells like gas.

I think my timing is out.
Questions:
Can the flywheel be attached in more than one location? I rotated it on the crank until I had the holes lined up. I assumed It can oly go on one way.
Also, concerning the timing chain. I read that the timing marks on the chain will move in respect to the marks on the sprockets when the engine is rotated. So, installing the chain and rotating a coup,e times to check the marks doesn't help, because the chain marks will be off. Is this correct?

 

[ImperialCrown]

The flywheel-to-crankshaft bolts have an offset hole, so the plate can only go on one way.
The darkened t/chain links are used to index the timing marks at assembly, once the engine is rotated, the index links are no longer in time with the sprocket marks.
It almost sounds like too much fuel is being injected and the engine is flooding. Wet plugs won't fire. Dry the cylinders for another try.
Does the engine sound like it is cranking over with good compression? If fuel has washed the oil off the cylinder walls, try a squirt of engine oil in the spark plug holes and crank it over. Disable the fuel pump and dry out the engine and change the oil if you feel that to much fuel has entered the crankcase.
Using a rod (plunger) and dial indicator in the #1 spark plug hole, get the #1 piston to TDC to verify the the #1 intake and exhaust valves are closed. The #1 cylinder is on the right (passenger) side of the engine. You may have to rotate the engine one more turn to get on the #1 cyl compression stroke. The left cam timing mark should be pointing straight up. The right cam timing mark should be canted slightly inboard.

 

[chuzz]

After trying what IC suggested, maybe you should try a shot of starting fluid to see if it hits.

 

[lotharamc]

Concerning the timing chain moving in respect to the alignment marks I think I should have verified the number of links between the crank and cam sprockets before, but i am disassembling to the timing chain now, and will verify it soon.

My compression seems good even now. I've been trying to start this thing for a week now, and in all my attempts to find the problem I have turned it by hand and the compression seemed good by feel. You know a pretty good amount of resistance accompanied by a slight hiss as you pass that particular point.

I have tried may things to find the problem, carb cleaner in the throttle body included. I have rebuilt may engines before but this one has me baffled. If this were an older car as I am accustomed to working on, I could count on having spark and fuel, but not running result in a weird firing problem, such as installing a distributor 180 deg. Off and having it misfire through the carb. I don't get anything like this**(see ps) not a stumble or caugh. It's just not catching at all. It ran good when i took it out, just with a rod knock.

PS
I had a helper turn it over and I put my hand over the TB, and then the exhaust pipe to verify that al least it was pulling air in, and pushing it out. This "test" passed in that it did what it should. With the exhaust the cranking would almost stop. As it should. With the TB partially blocked with my hand, the cranking would become more labored and slow down some. Not really a lot, but noticeable. Maybe 80% of normal cranking speed. When this happened, I got what I would assume to be a premature hit that would stop the cranking for a second. (sound this out like a car talk spot) wer wer wer b... Wer were wer b.... We're wer wer b... By this description I would even recommend to myself that the spark was too soon, and that the chain were off a link or two. However, if this were the case wouldn't I have this happen all the time? I would think I would consistently get a weird hit that would stop the cranking every time, or at least stumble. Right now at full cranking speed I'm getting nothing.

 

[ImperialCrown]

Any chance of a fault code yet? Was the battery disconnected for the rebuild?
Do you have a scan tool to see if cam and crank sensors are there and 'synced' while cranking?
Crank it over with the plugs out to dry the cylinders and bring cranking speed up for this test.

 

[dana44]

Kind of a back to basics. Check the timing position first, then verify the firing order with the coil packs, then the firing order for the injectors , proper connections for the cam and crank sensors, had a recent case of a cam sensor plug that interchanged with another sensor, switched them and things were fine.

 

[TWX]

How easy was it to turn by hand? There could be a compression issue if it's too easy. A cylinder pressure test could help determine that.

 

[lotharamc]

No fault codes yet, except for one time I had forgotten to plug in the intake temp sensor (iat?). I never thought about turning it over with the plugs out to speed things up and maybe get a code I wouldn't get otherwise. Good suggestion.

I'm pretty satisfied with the compression as felt by turning it over by hand. I don't think a valve is hanging open or anything like that.

As far as things being connected correctly. I am very sure the correct # injector/coil wire/sensor wire is where it should be. I labled everything, and just how the wire harness is laid out, you would have to intentionally try to connect things in the wrong order. There is no way to switch the crank/cam sensor wires on the 2.7. They are way to far away from each other, at least on a 5speed.

I finally got into the timing chain again last night, but it was too late to check anything. I'll have to get at it tonight.

 

[lotharamc]

The timing chain is on correctly all three of them. It's back to figuring out why it won't catch again. It will take some time to get it back together since it is the start of the week, but I will report back again when I get a chance to turn it over again.

Thanks for all the help.

 

[lotharamc]

Everything is back together, and it still won't catch. I did the ignition on,off,on,off,on thing, and I get p1684, p0123, p0118, p0353, p1193

These are, battery disconnected in the past 50 starts, Throttle position sensor voltage high, Coolant sensor voltage high, #3 coil not reaching peak current, Inlet air temp sensor circuit high.

As I see it this is one of two things. Either the PCM is bad, or I have a shorted, or grounded wire. All of these except for the battery thing are on the same branch of the wiring harness. I will check the harness upstream from them. I really hate finding bad wires. I think the wire thing is likely since it ran fine before I messed with it. Is there any chance that if one of the sensors, or whatever doesn't get grounded, or is shorted that it would mess up the other sensors voltages, thus throwing a code for them as well?

Also, just for reference, are PCMs specific to the options on the car similar to how body controll modules are? I realize a 4cyl won't work for my 2.7, but if I have to have one for a manual 2.7 I could be in for some trouble finding one.

 

[dana44]

Voltage too high is usually a short, and since you did identify them all in the same harness section, might have been a quick crimp with something heavy during assembly, I always hate when that happens, but gotta check it, happens more often than anyone wants.

 

[ImperialCrown]

'Sensor voltages high' faults are usually an open circuit, like a connector left unplugged or ground left off when the ign key was turned on. The sensors have 3 terminals:
1) 5 volt supply in. Orange wire from the PCM shared with other sensors.
2) signal voltage out, between ~1v to ~4v. To the PCM. (0v or 5v will set a low or high fault code).
3) ground. Usually black or black/* with a tracer stripe.
If the ground is open, the signal line voltage will be close to 5 volts. This will set the 'sensor voltage high' faults that you are seeing. The sensor needs the ground to pull the signal voltage down into the proper voltage range. It works as a voltage divider.
http://en.wikipedia.org/wiki/Voltage_divider
Low sensor voltage faults are usually from a short to ground. Grounding will pull supply or signal line low, near 0.
The 5 volt sensor supply will turn off (go into protection) if it detects a short to ground. This will protect the internal PCM regulated 5 volt power supply from possible damage. Even if the short is removed from the 5 volt line, the PCM will not come out of protection until an ign key off-on cycle. Then it will resume 5v output again.
I doubt that the PCM has been damaged. More likely a wiring harness/ground circuit/unplugged connector/broken wire problem.
Recheck the underhood harness.

 

[lotharamc]

Heading out to go over the harness. I'll report back when I get in.

 

[lotharamc]

Well here is what I did. Example: Ignition on, and coolant temp sensor disconnected. At the plug I got 4.94 volts. When connected it gets 2.73 with the probes.

All of the offending sensors did the same or similar. They are all spliced in and grounded through the same wire. The wire tested good throughout the harness. Shouldn't it have started regardless of these sensors? It may run like crap, but it should catch shouldn't it?

It did do something strange. I tugged on the main part of this branch of the harness to get a little slack to test one of the sensors, near the cam sensor, but upstream from it and the other sensors in question. When I tugged on it, one of the injectors discharged. I duplicated this a couple times. So, I had a helper turn the car over while I did this to see if it would catch, but no luck. I unraveled the harness in this location, and couldn't duplicate the injector pulse. I probed the harness at numerous locations and didn't get anything wrong. I think I had just pulled on it just right to make the cam sensor loose contact, but I don't know.

I'm out of ideas other than the PCM. is there any way the PCM would go into a mode where it won't let the engine fire. Like if it doesn't get a cam signal it will keep the engine from running until the error has been erased?

 

[lotharamc]

Is there some way to reset the PCM? I tried disconnecting the battery overnight but it didn't help.

 

[ImperialCrown]

If the orange sensor 5v supply wire is being pulled down to 3v, there is a problem in the wiring or with another sensor on that branch. It will not start or even run badly like this. It won't run at all.
Pulling on the harness and getting the injector to fire is a definite problem. If it is an intermittent connection at the cam sensor, that's bad there should be a secure connection at everything. Wiring harness movement should not make-or-break connections at all.
You are getting closer.

 

[lotharamc]

The coolant sensor was 2.73. The 3 wires on the cam sensor was 8.76 for the orange and 4.96 for the signal.

However, the tps is 4.94 at the signal, but only .48 at the orange constant. Is that even possible? I checked it multiple times. Also, the orange wire tests at 4.54 when disconnected.

 

[ImperialCrown]

This car must have the cam and crank at 8 volts and the other sensors at 5 volts. They did away with this difference around this time and ran all sensors at 5 volts. These sensor supply voltages are regulated within +/- 0.2 volts of the supply voltage.
The vehicle battery must be fully charged and your meter accurate.
The signal line voltages should be somewhere between 1 to 4 for the 5v sensors and ~0 to 8 for the 8v sensors. Don't be confused about the sensor signal readings, the supply voltages are more important right now.
The TPS is low (~0.5v) at idle and increases as the throttle opens (~4.5v). The MAP voltage signal is high with atmospheric pressure (low vacuum-engine off) and goes low under an idle speed manifold vacuum.
Could I be mistaken about the supply wire colors?
A valid cam and crank sensor test would best be taken with the engine cranking over to watch the voltage change (it is a square waveform as the trigger wheel passes the hall-effect). A cam and crank sensor voltage while sitting still doesn't say much. Your meter sampling rate may not be fast enough to watch the voltage 'pulses', but would read all over the place. A scope is the preferred tool for this.
I still suspect a wiring issue as the PCM should not have gone bad just sitting there while you re-did the engine. The 'signal high' fault codes indicate to me a wire may have gotten pinched or broken or a ground is disconnected or missing.

 

[lotharamc]

By accident i found the PVC heater location in the wiring diagram. Outside the rectangular box it is titled PVC heater, inside the box is more of a statement saying it is part of the auto shut down circuit, and indeed one of the lines out of the asd is what powers this PVC heater. I get no reading with it disconnected, and also nothing connected. Is this something that only comes on when running?

 

[ImperialCrown]

Here's the wire colors:
The 5 volts from the PCM to the EFI sensors is a Vt/Wt.
The 8 volt supply to the cam and crank sensors is an Or wire.
The PCV heater is 12 volts on the DG/Or wire only when the ASD relay is on.
The ASD relay may not be coming on without the car started and running.
It will not start without a crank position sensor signal or the 5 and 8 volt supply lines up. The PCM will latch the ASD on after crank signal is present. It may turn the ASD and fuel pump relays on briefly at 'key on', but won't keep them on without knowing that the engine is turning.

Edit: At the same time you want good grounds at the sensors. As close to 0 as possible measuring to the (-) side of the battery or body. No more than 0.2 or 0.3 volts.