|10-14-2013 05:24 PM|
4.0 hesitation issue
it does make sense espically with the older jeeps that a bad ground could be the problem and i,m going to run a wire from the sensor to a good ground and also put another ground to the engine from the battery
|10-14-2013 05:20 PM|
|07-05-2013 07:11 PM|
|Getaway84||What color was the wire that u grounded?|
|10-04-2011 02:46 PM|
|jeepinmike||crappy grounds are many times the cause of strange issues like this....|
|10-03-2011 10:50 PM|
|Jerry Bransford||What a sweet fix, that was some very nice detective work Forward!|
|10-03-2011 10:35 PM|
|Forward||Ok here is what fixed mine. I don’t know if this will fix yours but it is cheap enough to try. After looking at each connector in the loop of the cam shaft position sensor I found them all in good shape. I was only getting the P0016 (Cam shaft position sensor) code. I finally figured out that instead of letting off the gas until it stopped acting up I would hold it to the floor until the CEL(check engine light) came on. I would then have a code to follow. I got the code by turning the key from the off position to the point just before the motor starts 3 times in a row. This will give you the code reading right on the dash. When it is done giving codes it will say done. I still had the P0016 code. I replaced the cam position sensor for about $50.00. I left the battery disconnected over night to clear the code and the CEL went off. It may not need to be disconnected for that long but I was done for the night and just put all back together the next morning. Test drove the Jeep and still had the problem. I Got the P0016 code on the new sensor. I figured there must be a fault of some kind in the wiring harness. I went to NAPA and got the counter guy to print me off the wiring diagram for my truck. I found the Cam position sensor and found one wire was a 5vdc one was ground and one was communication wire. I went to Radio Shack and picked up a $2.00 “T” connector kit (see photo) a small roll of wire $5.00 and installed them between the plug on the sensor and the negative on the battery. I used the connectors in the kit on the sensor end and used an “eye” on the other end of about 18 inches of wire. I have put about 200 miles on my truck with no more issues. Today I moved the ground from the battery to a permanent place on the body to provide a good ground. I really hope this fixes your issue as well.|
|09-17-2011 12:06 PM|
|Arch Stanton||My 04 TJ Sport jerks/bucks a little when I'm I driving between 40-55 mph and I ease off the gas and am cruising a constant speed. A 4cyl pick up truck I had did the same thing at about the same speeds. Could this have something to do with the fuel injection? I don't know if it's my imagination, but it seems to do it more often when it's closer to the 5,000 mark just before I do the Mobil 1 synthetic oil change. I have until the end of October before the warranty expires and would like to get it fixed under warranty if it is indeed a problem.|
|09-17-2011 09:15 AM|
|Forward||Well finally got my Jeep back after replacing the CPS (crank shaft pos. sensor) and had the induction system cleened. i still have the problem. not sure what is next.|
|09-11-2011 10:57 PM|
ok i will admit i was having some trouble following the reasioning behind the valve being the issue. here is something i found online that seems to give an explanation:
here is the link:http://jsautosource.com/my-projects/...-rough-no-dtc/
TSB 09-003-03 Jeep 4.0 Engine Running Rough No DTC
DATE: Aug. 01, 2003
4.0L Multiple Cylinder Misfire OVERVIEW:
This bulletin involves inspection of all engine exhaust valves and a decarbonizing procedure if necessary.
NOTE : THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 4.0L ENGINE (SALES CODE = ERH).
The customer may experience an incident of engine misfire during certain vehicle operating conditions. The misfire may occur when the vehicle is operated between (50 – 70 MPH) and under light loading conditions, e.g. slight uphill road grades. This condition may occur at all ambient conditions, but is more noticeable when ambient conditions are less than 0°C (32°F).
If the vehicle is equipped with On-Board Diagnostic (OBD), a MIL illumination may also have occurred due to Diagnostic Trouble Code (DTC) P0300 – Multiple Cylinder Misfire. Various single cylinder misfire DTC’s may also be present. If the frequency of misfire is high the Powertrain Control Module (PCM) may place the engine in “Limp-In” mode.
The misfire condition may be caused by one or more engine exhaust valves that are slow to close. Late closure of an exhaust valve may be the result of no valve rotation and associated build up of carbon on the exhaust valve stem.
Jeep Cherokee Wranger 4.0 Engine Running Rough no DTC TSB Fix | J's Auto Source
1.This condition may occur when the engine is not allowed to run at engine RPM’s that are greater than 3,200 RPM. At 3,200 RPM or higher the engine exhaust valves will rotate if not impeded by high carbon deposits. Low engine RPM’s and high carbon deposits are associated with short trip driving where the vehicle engine is not allowed to fully warm to normal engine operating temperatures. Cold ambient temperatures will increase engine warm-up time and add to the opportunity of carbon deposit build-up on the stem of the engine exhaust valve.2.Verify that an engine misfire condition is present. Use of the DRBIII(R) during a road test, or a Co-Pilot data recording, may help to determine engine misfire and misfire counts. If carbon deposit accumulation is severe, then a cylinder leak down test may detect one or more cylinders leaking greater than 15%. Save any misfire DTC Freeze Frame Data that was stored for later misfire correction verification.3.Verify that the engine misfire condition is not caused by faulty engine mechanical or electrical components.4.If the engine mechanical and electrical systems are operating properly perform the Repair Procedure.
1.Raise vehicle hood.2.Remove the engine valve cover and all six exhaust valve rocker arms (the intake rocker arms are also removed during this step). Refer to the appropriate vehicle Service Manual for detailed removal instructions. The valve cover gasket is reuseable. Keep each pair of rocker arms matched to their respective valve and cylinder.3.Inspect the end, or tip, of each exhaust valve stem where it makes contact with the respective rocker arm.4.Determine if each exhaust valve is rotating within its respective valve guide. An exhaust valve that is rotating will have a “bulls eye” or circular wear pattern on the face of the valve stem tip. If the exhaust valve is not rotating a straight mark-like pattern will be present across the face of the valve stem tip.5.If there are exhaust valves which are not rotating then proceed to the VALVE ROTATION section of this Repair Procedure.6.If all exhaust valves are rotating, then this bulletin does not apply and further diagnosis is required. Install the engine rocker arms and valve cover. Refer to the appropriate vehicle Service Manual for detailed installation instructions.VALVE ROTATION:
1.If one or more engine exhaust valves are not rotating, perform the valve rotation procedure to all six (6) exhaust valves.NOTE :IT IS IMPORTANT THAT THE VALVE ROTATION SECTION OF THIS REPAIR PROCEDURE BE PERFORMED.
2.Clean and mark the tip of each exhaust valve stem with a paint marker. The paint mark will be used later to assist with determining if the exhaust valve has been rotated 90°.3.Bring number one ( # 1) cylinder piston to top dead center using the mark on the crankshaft front dampener/pulley. This step is important to prevent the possibility of the exhaust valve from falling completely into the cylinder.4.Install the essential service tool valve spring compressor, MD-998772A, to the # 1 cylinder exhaust valve spring.NOTE : THE FOLLOWING VALVE ROTATION PROCEDURE WAS DEVELOPED WITH THE USE OF VALVE SPRING COMPRESSOR TOOL MD-998772A. THE MD-998772A IS AN ESSENTIAL SERVICE TOOL AND PART OF THE DEALERSHIP REQUIRED TOOLS. THE MD-998772A COMPRESSOR ENGAGES THE ENTIRE PERIMETER OF THE VALVE SPRING RETAINER, UNLIKE OTHER MAKE VALVE SPRING COMPRESSORS.
5.Compress the # 1 cylinder exhaust valve spring enough to gain access so that the exhaust valve can be rotated 90°. Rotate the exhaust valve 90°. Slowly remove the compression on the exhaust valve spring. Verify that the valve keeper is properly seated to the valve stem and valve spring retainer.6.The 4.0L firing order is 1 – 5 – 3 – 6 – 2 – 4. Without rotating the engine crankshaft repeat steps 3 through 5 to cylinder # 6.7.Rotate the engine crankshaft 1200 and repeat steps 3 through 5 to cylinders # 5 and # 2.8.Rotate the engine crankshaft another 1200 and repeat steps 3 through 5 to cylinders # 3 and # 4.9.Install all cylinder rocker arms (intake and exhausts) and retaining bridge. Make certain that the push rods are properly seated to their respective rocker arm and lifter. Tighten the respective cylinder bridge/rocker arm cap screws to 30 Nm (21 ft. lbs.) when each cylinder piston is at top dead center (cylinder intake and exhaust valves are closed).10.Install the engine cylinder head valve cover. Tighten the valve cover bolts to 10 Nm (85 in. lbs.). Refer to the appropriate vehicle Service Manual for detailed assembly instructions.DECARBONING COMBUSTION CHAMBER AND VALVES:
1.Start the vehicle engine and allow the engine to reach normal operating temperature.2.Remove the air tube from the engine throttle body.3.With the engine at idle, spray the entire contents of Mopar Combustion Chamber Cleaner, p/n 04318001AB, directly into the throttle body. As the cleaner is being ingested, allow the vehicle to “load up” with the cleaner to the point that the engine is almost stalling out. Maintain this condition until all of the cleaner is used/ingested.4.Stop the engine once the entire can of cleaner has been ingested.5.Install the air tube to the throttle body.6.With the hood closed and the vehicle parked inside the garage, allow the vehicle engine to heat soak for two to three hours. This will ensure that the engine will maintain its temperature and will allow proper solvent penetration.7.After engine soak, start the engine and drive the vehicle until the engine is has reached normal engine operating temperatures.8.If the vehicle is equipped with an automatic transmission, place the gear selector into “L” (low). If the vehicle is equipped with a manual transmission, place the transmission into first gear.9.In a safe vehicle operating location that will allow the vehicle to be driven safely and at the posted speed limit, accelerate the vehicle until the engine reaches 4500 RPM.10.Hold the engine speed at this RPM for 15 seconds.11.Slow down and in a safe location pull to the side of the road. Allow the engine to idle for five seconds.12.Repeat steps 9 through 11 five more times.13.With the vehicle at operating temperature and using any available Freeze Frame data recorded when the misfire DTC occurred, verify that the misfire condition has been corrected.14.Erase any engine DTC’s once the misfire condition has been corrected.
|09-10-2011 09:53 AM|
Hey Forward...That's exactly what was mine was doing. Not all the time mind you, but it would also act up at approx. 55 + mph. I would just feather the throttle until I pushed through the problem. I took mine in 3 times before it acted up. They finally got it to act up but it did so quickly that it didn't even register on the computer, but they that based on how it acted it was the valve springs. It never throws a code, nor does the engine light come on. They would have my Jeep all day for 3 days, and it never acted up. As soon as I pulled out of the lot...it would act up. I told them not to try to make it act up because there wasn't any type of driving that would make it do so. I told them just to drive normally. Anyhoo...I think that we may be on the right track to solving the problem for good.
|09-09-2011 06:44 PM|
|Forward||Thanks KFDJason7620, i just left the shop and they have been driving my jeep off and on all week (most likely to lunch and back) and it will not cut out when they drive it. i took it for a spin down the high way and it cut out once. i was traveling between 50 and 55 at about 1800 rpm with a stedy pressure on the gas just crusing. they told me they would hook up a computer to the truck and then drive it on the same road i did and see if the computer will catch anything acting out of line. Bucknutz1070s last post is also a good description of what mine is doing.|
|09-09-2011 12:12 PM|
Jeep dealerships use Mopar CCC (Combustion Chamber Cleaner) for such work, not Seafoam. It commonly is added until the engine dies when it is then allowed to "cook" so it loosens carbon deposits that are then able to be blown out in the exhaust after the engine is restarted.
Rough idling is usually caused by one of the following... a bad (dirty internally, cannot be cleaned) Throttle Position Sensor, sticking (can be cleaned) Idle Air Controller, worn distributor cap and rotor (replacements should have brass, not aluminum contacts), or perhaps worn valves or valve seats which can be verified with a compression test.
As said above, springs don't stick but valves can stick from weak valve springs or other valve train problems.
|09-09-2011 12:09 PM|
|09-09-2011 12:02 PM|
|BuckNutz1070||I'm running the high mileage oil...I believe it's Castrol.|
|09-09-2011 12:01 PM|
|BuckNutz1070||No...It fires right up. I do not get an engine light...all of my gauges are normal...no error codes. That's what is weird about it. It has very died on me. It will last for about 15-20 seconds, and I just feather it until it starts running normal again.|
|09-06-2011 07:15 PM|
|09-06-2011 07:09 PM|
|Forward||I have an 05 TJ with an auto trans. mine is in the shop now for the what sounds like the same thing. mine sometimes hesitates when i hit a bump in the road. The mech there told me it was a sensor going on on the bell housing and it was also common on Dodge trucks. he said when it did go out it would die and not start back. i will post what they find. was yours happening when you hit a bump? on a smooth road i have no issues and it seems to run normal. only one time did the check engine light come on but it went off the following day.|
|09-06-2011 10:42 AM|
|hambubba||Springs don't stick - they break. I think they missed the problem. The "pour it in until it dies" doesn't sound like a repair I would want!|
|09-06-2011 09:45 AM|
No...I just starts to nose down periodically...and starts spitting/sputtering. If you check my Continued hesitation post, it probably would help you out better. I posted it about 1 year ago. It starts just fine. They checked the fuel pump, fuel injectors and said those were perfectly fine. Only reason I suggested for you to read my earlier post is that it's kind of long and more in depth. I'm just too lazy to re-type it....LOL. Thanks for your input...\m/ \m/
|09-05-2011 02:03 PM|
|NHWRANGLER||by hesitation, do you mean it cranks for a few seconds before firing? cause ive had that problem and valve springs is what everyone says.|
|09-05-2011 01:59 PM|
|ky-homelite||What did they put in? Sounds similar to Seafoam or something along those lines. What kind of oil are you running in your engine? Maybe try something with a little more cleaning capabilities?|
|09-05-2011 12:24 PM|
Continued Hesitation Mystery Solved!!
Well...found out what the problem is. I finally took my 1999 TJ to a Jeep Dealership, and after a few times taking it to them, because it would never act up. It was determined that the valve springs are sticking, which according to them, that would explain the hesitation and rough idling. So...they went ahead and treated the upper engine with a high quality type of solvent. They had the ending running and pour this solvent into the engine until it completely died. They let it sit for about 4 hours. It actually worked for a long time, but now it has started acting up again, but very much less frequently. So...if it in increases in frequency, then I will probably have to have the valve springs replaced, which will run me approx. $200.00 +. So...if anybody else has the same problem with heir Jeep...this is something to look at. Thanks for everyone's input...\m/ \m/