Help guys, truck running crappy and I give up!

[VENOMOUS1 RACING]

I have been for the most part silently trying to fix an issue with the 10 that aggrevates the crap outta me. Usually ask for help at my wits end, so here I am. My mileage has gone to crap from 14.5 to about 11.5 and the power seems to come and go. I am 99% confident it is a sensor, but which one?
Scenario:
Mostly happens at cruising speed around 60MPH with a steady throttle and even road. Seems to have something to do with the throttle being barely open, whether cruising through a parking lot with the throttle barely cracked, or doing 60 with throttle barely cracked. Pretty much another reason I was thinking TPS. The engine will start sputtering and falls on its face and I have to give more throttle to maintain speed. As soon as I hit the gas a little more, she darts forward and quits the sputtering. While she does this there is a messload of unburned fuel coming out the exhaust to the point where I smell it in the cab at 60mph? I have tried to just let this continue on to get a check engine light or something, but she never says anything. ( my check engine light does work) She also shifts quicker than she used to like and older car with a vacuum leak at the tranny modulator. Just normal accelerating it shifts to second at about 10 mph and all the other gears early bogging the motor down. I believe this is caused by whatever sensor is involved with tranny shift points also.

Here are the things I have done to remedy this situation to no avail and what I think could be culprit. I am going to try and borrow a Scan Tool that Chrysler uses to log and visually watch the sensors as I am driving and when it acts up see what is acting up.

1. Changed plugs and wires
2. Added Screamin Demon coil packs.
3. Changed tranny fluid and filter and new tranny sensors from MOPAR
4. Changed TPS as this seemed reasonable by everyone else's issues like this.

None of the above made the slightest difference at all with respect to fixing the issue at hand.

Things I think could be culprit:
1. Fuel pump/filter which I cannot access to change? Acetone her?
2. MAP sensor since that feed the computer all airflow info since we have no
MAF.
3. Coolant temp sensor- Have seen them read 0 degrees on a 90 degree day and vice versa.
4. Intake Air Sensor- seen them read incorrect temps and cause issues.
5. Cam and Crank sensors? I go more likely with cam sensor as I've seen more cars not even run with bad crank sensor.

Please help if you have run into anything similar or have any knowledge to share.

Thanks, Scott

 

[Silverbullet08]

i know i have a hemi but mine kinda did this where it seemed like it wouldnt want to go and shift all crazy. turned out it was the crankshaft sensor.

 

[DevilDawg3097]

did you put the vacuum line back on under the throttle body? that will cause all kinds of havoc. It sounds more than likely it is a vacuum leak somewhere or something is causing the ecm to run very rich (which is dumping fuel). When exactly did it start to happen before or after you did all that stuff?

 

[VENOMOUS1 RACING]

did you put the vacuum line back on under the throttle body? that will cause all kinds of havoc. It sounds more than likely it is a vacuum leak somewhere or something is causing the ecm to run very rich (which is dumping fuel). When exactly did it start to happen before or after you did all that stuff?

No, it was doing this well before I did the mods. Trying to fix the issue led me to replacing the plugs and wires, therefore removing the intake so I painted it. I figured I'd leave it down for week longer to order the new coils from Stinker to rule that out while I had the intake off. She only does this sputtering thing about every 20 miles or so -/+. When it does it, no sooner than I hit the peddle it clears up. Led me to believe it was the TPS. I mean it would go from running like crap stinking up the cab with gas, to pulling hard and smelling clean again with about a 1/4" of throttle acceleration. Not a 1/4 pedal, but 1/4"? All vacuum lines I removed are reinstalled and like I said, it was like this prior.
Another weird thing that made me think TPS especially after searching here is it has a seemingly rough idle, almost like cammed? As soon as I put it in Drive or Reverse it idles smooth?

 

[DevilDawg3097]

ENGINE STALLS OR ROUGH IDLE 1. Vacuum leak. 1. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
2. Faulty crank position sensor 2. Replace crank position sensor.
3. Faulty coil. 3. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL). Check all your vacuum lines even the ones you didn't touch. Obviously you eliminated those Items, but never fixed the original problem. The smallest little leak with mess with the ecm since most of the fuel systems is tied into the vacuum system. I found a bad line going up into the dash for the evap system. just a thought.

 

[DevilDawg3097]

ENGINE STALLS OR
ROUGH IDLE
1. Carbon buildup on throttle plate. 1. Remove throttle body and de-carbon.
2. Engine idle speed too low. 2. Check Idle Air Control circuit. Refer to
the appropriate Diagnostic Information for
IAC motor testing.
3. Worn or incorrectly gapped spark
plugs.
3. Replace spark plugs or set gap.
4. Faulty or crossed ignition cables. 4. Check for correct firing order or replace
ignition cables as necessary.
5. Faulty coil(s). 5. Test and replace as necessary.
6. Intake manifold vacuum leak. 6. Inspect intake manifold gasket and
vacuum hoses. Replace as necessary.

 

[Venom Power]

Don't give up Scotty... Or that Bee in your sig picture will end up trading places with your QC.

 

[VENOMOUS1 RACING]

ENGINE STALLS OR ROUGH IDLE 1. Vacuum leak. 1. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
2. Faulty crank position sensor 2. Replace crank position sensor.
3. Faulty coil. 3. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL). Check all your vacuum lines even the ones you didn't touch. Obviously you eliminated those Items, but never fixed the original problem. The smallest little leak with mess with the ecm since most of the fuel systems is tied into the vacuum system. I found a bad line going up into the dash for the evap system. just a thought.

I am starting to agree with the Crank sensor part., just don't wanna start thrwing parts at her. It seems very much that this is a problem that occurs when I am just off idle. Whether putting through a parking lot, or cruising 60 with pedal in about the same, barely open position. It is intermittent when it does the sputtering thing and there is no indiction on the tach that it's a miss. More like getting flooded with fuel and bogs down. I am wondering about the vacuum lines more now, since it seems that the function door that changes from defrost to vents etc. seems really slow. Unless they are not vacuum operated anymore? I definitly don't hear a hiss anytime indicating a vacuum leak though. Still gets me that as I transition the shifter from park (rough idle, but smooth tachometer) to drive ( smooth idle) the idle clears right up? Trying to get all the symptoms out there to help you guys help me. Literally this has gone on for months.

 

[Troy's QC SRT]

it's very possible to not "HEAR" a vacuum leak. There are quiet a few methods in finding a vacuum leak.....you can pressurize the intake manifold with about three lbs. of regulated air. This can be done by attaching a regulator to your shop air hose, then attaching the hose to a vacuum fitting or the PCV valve fitting on the intake manifold or throttle body. Do not apply too much pressure or you may create new leaks! With the engine off and air flowing into the manifold, spray soapy water on suspected leaks. If you see bubbles, you have found the leak. A faster technique for finding intake manifold vacuum leaks is to get a bottle of propane and attach a length of rubber hose to the gas valve. Open the valve so you have a steady flow of gas. Then hold the hose near suspected leak points while the engine is idling. If there is a leak, propane will be siphoned in through the leak. The resulting "correction" in the engine's air/fuel ratio should cause a noticeable change in idle speed and/or smoothness.....

 

[VENOMOUS1 RACING]

it's very possible to not "HEAR" a vacuum leak. There are quiet a few methods in finding a vacuum leak.....you can pressurize the intake manifold with about three lbs. of regulated air. This can be done by attaching a regulator to your shop air hose, then attaching the hose to a vacuum fitting or the PCV valve fitting on the intake manifold or throttle body. Do not apply too much pressure or you may create new leaks! With the engine off and air flowing into the manifold, spray soapy water on suspected leaks. If you see bubbles, you have found the leak. A faster technique for finding intake manifold vacuum leaks is to get a bottle of propane and attach a length of rubber hose to the gas valve. Open the valve so you have a steady flow of gas. Then hold the hose near suspected leak points while the engine is idling. If there is a leak, propane will be siphoned in through the leak. The resulting "correction" in the engine's air/fuel ratio should cause a noticeable change in idle speed and/or smoothness.....

Thanks for the reply and I will give this a shot. I also no some shops have a smoke machine that can fill the intake and such and smoke comes outta the leaking area.

 

[Troy's QC SRT]

Yea there are multiple methods....those are just my to favorite...i didnt post the smoke method due to u most likely not having the equipment to do it at the house!

 

[Black1]

The exact thing was happening with my QC years ago... The ecm needed re-flashed with an update. It took care of the problem. How old is your Stage 2 ecm?

 

[VENOMOUS1 RACING]

The exact thing was happening with my QC years ago... The ecm needed re-flashed with an update. It took care of the problem. How old is your Stage 2 ecm?

Well that's the other thing I left out! I had the original ECM in there while it did this. I got a stage 2 B&G and it was still there. Later on I got the SCT with tunes on a different ECM and the same thing still so I can rule out ECMs and tunes. I still think a sensor is involved and not reporting a fault to the ECM? That or it is non ECM related such as Fuel Pressure by pump or regulator. Wouldn't an injector malfuntion show as a miss or running too rich if stuck open? Seems a Crank or Cam sensor is valid also because when it runs like poo it does seem retarded, no power. But all the sudden it jumps back to life and takes off again.

 

[DevilDawg3097]

only thing I can think of is find a place with a diagnostic machine and dyno. You would think there would be a million places but even out here there is only a handful. But you need to make some type of diagnostic if it isn't vacuum related. With a good machine even though your not throwing codes it can read when and at what point it drops possibly pinpointing it. just a thought.

 

[ViperJeff]

I will need to find it, however, I remember a lot of these same symptoms and same changes and the problem was the flexplate.

It was broken in about 6 pieces

 

[VENOMOUS1 RACING]

I will need to find it, however, I remember a lot of these same symptoms and same changes and the problem was the flexplate.

It was broken in about 6 pieces

Interesting, never heard about that one before? Does the Crank Trigger for the sensor use the flexplate for reference like some cars?:dontknow:

 

[linemup]

Could an injector be sticking?

 

[SANTEEN]

Interesting, never heard about that one before? Does the Crank Trigger for the sensor use the flexplate for reference like some cars?:dontknow:

Yup, I've heard of the flex plat cracking on our tucks, also.

 

[VENOMOUS1 RACING]

Any other ideas? I hooked it to a Genesys Scan tool yesterday and logged data and the only thing that really stood out was the Knock Sensor continuously bouncing from .29 - 4.57 volts every second. I'm sure this can't be good and damned if that's the only thing I didn't change under the intake! What I can't see is it affecting timing any really? Timing seems to stay around 30-33* at cruising 60mph and around 28*ish under throttle. Never seems to be affected by the knock sensor. It only shows one knock sensor as well and I thought I saw two under the intake? Unfortunately it never did the acting up thing while logging (20 min) but no sooner than I left my buddies shop it started bogging out again.:dontknow:
Didn't setup the damn logger to watch MAP though and that frustrated me as it was one of the sensors I am doubting.
Map Vacuum at idle is at 17 in/hg and MAP absolute pressure is 11.5 at idle.
Also plan to tape a fuel pressure guage to the windshield and watch what the fuel does when this thing acts up. For sure not 1 injector, because when it does this it falls on it's face like it's on 6 cylinders, so it would likely have to be the whole bank on one side failing and with 5 cylinders either not fueling or dumping too much fuel at once making it fall on her face?:dontknow:

 

[DevilDawg3097]

Any other ideas? I hooked it to a Genesys Scan tool yesterday and logged data and the only thing that really stood out was the Knock Sensor continuously bouncing from .29 - 4.57 volts every second. I'm sure this can't be good and damned if that's the only thing I didn't change under the intake! What I can't see is it affecting timing any really? Timing seems to stay around 30-33* at cruising 60mph and around 28*ish under throttle. Never seems to be affected by the knock sensor. It only shows one knock sensor as well and I thought I saw two under the intake? Unfortunately it never did the acting up thing while logging (20 min) but no sooner than I left my buddies shop it started bogging out again.:dontknow:
Didn't setup the damn logger to watch MAP though and that frustrated me as it was one of the sensors I am doubting.
Map Vacuum at idle is at 17 in/hg and MAP absolute pressure is 11.5 at idle.
Also plan to tape a fuel pressure guage to the windshield and watch what the fuel does when this thing acts up. For sure not 1 injector, because when it does this it falls on it's face like it's on 6 cylinders, so it would likely have to be the whole bank on one side failing and with 5 cylinders either not fueling or dumping too much fuel at once making it fall on her face?:dontknow:

can't tell you what the specs are for the knock sensor (04's dont have em) but if it is poppin off like that, that would be the reason it is dumping fuel a knock means detonation which triggers the sensor. So it may be as simple a s sensor. But on the other hand it could be something worse. If the sensor is good, now you need to figure what is triggering the knock sensor.