Leaking Fuel Injector

[RamFan]

Good evening folks,
I recently purchased an '04 Ram 1500 with the 5.7l Hemi. The truck was perfectly maintained and for the mileage and age is in absolutely great shape. That being said, I'm 99% sure it has one or more leaking injectors. On a cold start the truck starts up without any hesitation, should I turn the truck off and start it again within 5 minutes or so it'll start right up again. If I shut her down and let her sit for 10-15 minutes it'll typically start within a crank or two and idle roughly for 2-3 seconds then level out. If I let it sit for longer, when I go to turn the key it'll crank and crank and crank but never fire, as soon as I hit the accelerator issuing a clear flood signal she'll turn right over. The rough idle start and accelerator assisted start are also accompanied with a strong smell of gas. Yesterday I replaced the cam position sensor just on the off chance that, that was the issue and it clearly is not. Thus I'm left with having to replace a fuel injector or more. No big deal, just going to pull the rails and injectors and see which ones are leaking. It's a relatively easy job but I, as many of you are, am simply pressed for time and would rather not spend an afternoon to do the job. With that being said, is there any secret cleaning method that I could give a shot first that might remedy the problem? Techron or some kind of 2-step cleaning?

 

[eljefino]

You could come up with some math scheme to unplug 4 injectors and see if it floods, then the other 4, then when you find a good bank plug 2 more in, etc.

Of course you may have to be counterintuitive and see when it runs better with just what's leaking down.

You'd have to know if it opens then leaks as it's shutting or is always dribbling.

When I had a really bad leaking injector on my silhouette van I had a misfire code for that cylinder, it ran BETTER on the highway when it needed lots of fuel, the spark plug was soaked in gas, and the upper intake gasket for that cyl was damp.

 

[Trav]

Does it have a MAF sensor? Look at that first if it does or air leaks/cracks in the TB intake hose.
This engine uses a decent Bosch injector with a SS disk, it would be rare for one to stick open but not impossible.

Its probably copper colored on the bottom, that is the injector itself, give each one a light tap with a small hammer and brass punch at this point. Do not whack the daylights out of it just a few small taps.
This will sometimes free one that is sticking. Run a can of berrymans Chemtool in a low tank.

 

[RamFan]

Originally Posted By: Trav
Does it have a MAF sensor? Look at that first if it does or air leaks/cracks in the TB intake hose.
This engine uses a decent Bosch injector with a SS disk, it would be rare for one to stick open but not impossible.

Its probably copper colored on the bottom, that is the injector itself, give each one a light tap with a small hammer and brass punch at this point. Do not whack the daylights out of it just a few small taps.
This will sometimes free one that is sticking. Run a can of berrymans Chemtool in a low tank.


No MAF, just an IAT. If it was the IAT I would expect it to start poorly every time not only after being shut down for after 10-15 minutes. It's for this reason that I'm thinking the injectors are the culprit. But you are right, this isn't a common issue on the Hemi's from what I can tell.

P.S. I'm thrilled you stumbled upon this thread so quickly

 

[DR Racing]

At 155k you need to have all of your injectors professionally off the vehicle cleaned. No need to buy new ones. Contact RC Engineering. I have seen engines destroyed from ignoring dirty injectors. The only right way to do it is off the vehicle.

Dan

 

[paulo57509]

Leaking injectors is a rather easy diagnosis if you have a pressure gauge.

Don't ignore the possibility that it might be a temperature related thing. The ECU may think the engine is still cold and adding additional fuel during start-up.

 

[Vikas]

Talking about IAT, it should read correct intake air temperature even if the engine is off, correct? If you ever see bogus number on it (even with engine not running), it may be faulty. Does anybody know of any case where IAT only gives correct value when the engine is actually running?

 

[Trav]

Engine On/Off it should give and accurate reading. Hot engine will usually be a little higher as the engine is heating the surrounding parts.

I am thinking this is more of an issue in closed loop.
Checking the fuel pressure regulator and seeing if it holds pressure will be on the list of things to check as another poster pointed out.

Any CEL or codes?

If the injectors are really dirty i can clean them, i also have brand new OEM Chrysler branded Bosch in stock if it comes down to that. PM me.

 

[The_Eric]

Originally Posted By: DR Racing
At 155k you need to have all of your injectors professionally off the vehicle cleaned. No need to buy new ones. Contact RC Engineering. I have seen engines destroyed from ignoring dirty injectors. The only right way to do it is off the vehicle.

Dan


This should read "Contact Hurst Injector Service" IMO...

Member Trav runs the place and has been more than helpful to the board members here. He would be my first choice.

 

[RamFan]

Originally Posted By: Trav
Engine On/Off it should give and accurate reading. Hot engine will usually be a little higher as the engine is heating the surrounding parts.

I am thinking this is more of an issue in closed loop.
Checking the fuel pressure regulator and seeing if it holds pressure will be on the list of things to check as another poster pointed out.

Any CEL or codes?

If the injectors are really dirty i can clean them, i also have brand new OEM Chrysler branded Bosch in stock if it comes down to that. PM me.


No CEL. I just made 2 videos replicating the issue, will upload when I get home.

 

[RamFan]

 

[Mackelroy]

I had a brand new ford one time on cold start the EGR valve would open and it would buck like a bronco at idle, restart it and it would be fine.

There was like a vsv adjustable air valve that fed vacuum to the egr valve , and its a delicate adjustment, maybe 1/8 turn was the difference between perfect , and failure.

I took it to the shop and they never could find issue, somehow I figured it out myself.

Just a thought, even though your issue sounds not the same.

 

[Warstud]

Change the Coolant Temp Sensor.

 

[Trav]

It doesn't seem like a sticking injector. One that is sticking generally will give a lot of smoke and a cel for a misfire on the effected cylinder.
As someone posted it could be a temp sensor for the ECM no the gauge. A scan tool on this engine should root out the culprit quickly.

Get it scanned if you don't have one, don't start throwing parts at it. No good comes from that approach.

 

[RamFan]

Ran to O'Reilly this morning to borrow their OBD2 scanner, threw a PO300, Random Misfire. Truck runs fine though, I don't get it.

 

[Trav]

Test the fuel pressure cold and warm, check for vacuum leaks. This can be tough to diagnose without data.
It can be anything from fuel pump/regulator, egr system to a failing coil pack/module and anything in between.
An misfire count for each cylinder would be helpful to see if the misfire was more on one bank than the other.

Do not drive this vehicle until this is resolved the cat is at high risk.

http://www.myautorepairadvice.com/p0300.html

 

[RamFan]

Problem solved! Due to lack of time I caved and took the truck to the dealer, cylinder 1 and cylinder 6 fuel injectors were leaking. Replaced the two injectors and the problem has been solved. Thank's for all the replies!