Hi guys. I have an intermittent starting problem. My 04 automatic aiways cranks. Sometimes it starts first time, other times it can take up to 8 tries. I've replaced the rcm, all relays, crank position sensor, camshaft position sensor and ignition switch. Any suggestions?

 

You asked, so here we go. I'd suggest you diagnose the problem before throwing parts and money at it. You tried to replace every part that is a common, ignition-related problem. You ignored something.

In the case of our cars, there is an important part of the engine system that has NO sensors on it and you will get NO CODES if a failure occurs. Just guess what that system is. Go ahead. It's the system you have ignored so far (from what you typed, that is).

I'ts the fuel system. There is NOT ONE sensor on the car telling the ECU what the fuel pressure is, instead, the ECU just assumes it's 58psi +/- 2-3 pounds.

There are two ways I test fuel pressure when a car won't start easily.

1) Get in car, turn key to ON and wait a count of three: "One-one, one-two, one-three". Turn key to start. If engine starts just fine this way but not "normally", you have a problem where the fuel system builds pressure slowly. My Ranger did this, so I always waited to turn the key. For three years. Then, one day, it quit running - the pump died.

2) Order one of these:
https://www.summitracing.com/parts/otc-5630
Screw it on to the valve on the engine, up front, under the air intake. Turn key ON.
If the pressure is not 55-60psi, get your fuel system fixed.

No one should be without a fuel pressure test kit, they are as easy to use (tho a bit more dangerous) as a tire pressure gauge (due to the gasoline that will spray out if you are not quick about it).

Once more, the ONE system on the car that is without sensors is the fuel injection. You MUST measure it manually, there is no other way to know if the fuel pressure is high enough to run the engine.
And on that note, the engine will start and idle as low as 25-30psi. But at such pressure, if you press the accelerator, it will sputter and shake. Pressures below somewhere around 12-20psi and the engine wont 'fire' at all.

 

And I'm done editing my post..... So go read it again as you are shown to be on here now, while I was typing.

 

fuel filter/regulator 90% clogged. to prove it turn key on(leave on for 5 seconds then off (with out starting) 3 or 4 times then start the car . do this for a week then u will no. jim
sorry mark didn't see your post .. when i posted it showed O reply we think the same but i let him,,or her find the parts so next time they will research before posting,,,oh, your right they will not research anything we are too quick to answer only because we love the crossfire ans hate to see one not running. again jim

 

I have checked fuel pressure at least a dozen times, pressure is always good.

 

Then it might be your starter, it is rare but a few members have had problems.

 

Or a bad or corroded ground?

 

could you go through the steps you did to check your fuel pressure.
as years ago i had the same problem u are having .
first i added a gauge to my fuel line, drove the car until the engine heated up (water gauge reads 1/2 way)
then parked the car,, next morning went out . ( with no other moves ,opened the hood) showed 591/2 lbs)
had my wife start car as i watched the fuel gauge i had installed . as soon as the engine started to spin
the fuel pressure went to 12 ,,,the second try the pressure went to 60 the car started . i replaced the fuel system with a manual fuel regulator with a return line with a check valve in going to the engine also added a new filter because the stock fuel filter and regulator are incorporated in one

 

How can it be the starter, he said it "always cranks".

 

If the pressure is fine and the car is that hard to start, we'v got to determine if spark is happening. You can do this by yanking a plug cable off and holding it near the block while cranking, you should get a spark.

If it is, then we must wonder if the injectors are being commanded to open. The only way I know to determine this, is to use an oscilloscope and probe the ECU-side lead of one of the injectors to see of the pulse is there.

Beyond that, I suppose we could look at the throttle body - is it open too far or closed too far such that the fuel/air mixture is way off?

As to the plugs AND injectors, these car's ECU seems to be FUSSY AS HELL about the parameters of their electric supply. That's a techy way of saying it can all be your battery.

If at all possible, substitute another battery. Yes, a battery can be sufficient to engage the starter and turn the engine over, and yet not start the car. I know it sounds like I"m talking foolish, but we've seen this time and again.
In fact, I had a Dodge Durango that did exactly this. We had it towed to a garage and they worked for an hour on it, could not see what was wrong.

Traded batteries between my van and Durango - Durango and van started right up. Swapped them back, Durango would not start.

The ECU/PTCM, what ever you call it, can do some WEIRD stuff because of battery voltage being too low or unstable. And you might read the code(s) to see if there are any pending codes that point to things like "too lean" or "too rich" as this might give you a clue as to what the ECU sees when the engine is running in closed-loop mode. Perhaps things are off enough to make starting hard, but not so far off that, once the engine is running, it prevents the engine from running.

 

THIS! ^^^^^^^^^^^^^^ what jim said ^^^^^^^^^^^^^ THIS!

 

Who cares, they rarely report back the resolution.

 

Moved from your other thread:

If you mean the Powertrain Control Module's C4 pin 25, the fuse is the 200amp fuse in the distribution box next to the battery. The service manual shows no other fuse in the line, which I find very unusual. Just know: There are many mistakes and omissions in the service manual. I suspect there IS an undocumented fuse in that line.

If you are trying to track down electrical issues without the service manual's diagrams (as bad as they are), you are wasting your time. If you find them hard to follow, it 's not you, its the poor documentation.