No Acceleration, Rough Idle and Stall Issue
05-26-2015, 07:56 PM
#41
Member
Thread Starter
Well I got the last plug out after quite some effort and now all the plugs are brand new SP515's. Unfortunately that has not fixed my problem.
But today I was blessed by the truck gods with a CEL right as my truck stalled in the usual place it does every day when I go to work.
Came up as a P0345 - Camshaft Position Sensor A Circuit Malfunction (Bank 2). I have to take a 20 mile drive tonight so my plan is to unplug the CPS on the driver's side and see if the truck runs any better. Then I'm going to spend some time trying to see if I can nail down the specific problem in the circuit. Hopefully it's the simple and easy case of simply switching out the sensor.
But today I was blessed by the truck gods with a CEL right as my truck stalled in the usual place it does every day when I go to work.
Came up as a P0345 - Camshaft Position Sensor A Circuit Malfunction (Bank 2). I have to take a 20 mile drive tonight so my plan is to unplug the CPS on the driver's side and see if the truck runs any better. Then I'm going to spend some time trying to see if I can nail down the specific problem in the circuit. Hopefully it's the simple and easy case of simply switching out the sensor.
05-27-2015, 07:41 AM
#42
Couple of things-
Your reported RPMs vs vehicle speed seems really high unless you have 4.30 gears. This leads me to believe that your torque convertor is not locking up as it should be. That could be a transmission problem but you won't know for sure until you get a scan tool capable of displaying whether the computer is commanding torque convertor lockup and the actual state of the convertor.
Second, thinking about what changes when the engine is cold vs hot, as your problem is only experienced with a hot engine, the first thing that comes to mind is the VCT system. The computer uses an oil temp sensor to know when it can command the VCT solenoids to change cam timing. Cam timing is fixed at full advance until the engine reaches operating temp. Once hot, the computer can change cam timing by up to 60°. I would start by unplugging both VCT solenoids. They are at the front top of both valve covers. The driver side is under the power steering reservoir bracket and will be difficult to get to. Unplugging them will trigger a MIL but will not harm your engine. Drive the truck and see if the problem is still there.
Understand that sometimes the VCT solenoid inlet screens disintegrate and can jam the solenoid. This prevents the computer from controlling the cam position at all and can lead to problems even when the engine is cold. This happened to a friend of mine. Shop told her she needed a new motor. I pulled both VCT solenoids. One had a broken screen with missing pieces, and the other was about to break. Less than $100 for 2 new solenoids and $26 for two new seals and her motor ran perfect again. It would barely idle and had no power before the fix.
Your reported RPMs vs vehicle speed seems really high unless you have 4.30 gears. This leads me to believe that your torque convertor is not locking up as it should be. That could be a transmission problem but you won't know for sure until you get a scan tool capable of displaying whether the computer is commanding torque convertor lockup and the actual state of the convertor.
Second, thinking about what changes when the engine is cold vs hot, as your problem is only experienced with a hot engine, the first thing that comes to mind is the VCT system. The computer uses an oil temp sensor to know when it can command the VCT solenoids to change cam timing. Cam timing is fixed at full advance until the engine reaches operating temp. Once hot, the computer can change cam timing by up to 60°. I would start by unplugging both VCT solenoids. They are at the front top of both valve covers. The driver side is under the power steering reservoir bracket and will be difficult to get to. Unplugging them will trigger a MIL but will not harm your engine. Drive the truck and see if the problem is still there.
Understand that sometimes the VCT solenoid inlet screens disintegrate and can jam the solenoid. This prevents the computer from controlling the cam position at all and can lead to problems even when the engine is cold. This happened to a friend of mine. Shop told her she needed a new motor. I pulled both VCT solenoids. One had a broken screen with missing pieces, and the other was about to break. Less than $100 for 2 new solenoids and $26 for two new seals and her motor ran perfect again. It would barely idle and had no power before the fix.
Last edited by VTX1800N1; 05-27-2015 at 07:49 AM.
05-27-2015, 08:52 PM
#43
Member
Thread Starter
Couple of things-
Your reported RPMs vs vehicle speed seems really high unless you have 4.30 gears. This leads me to believe that your torque convertor is not locking up as it should be. That could be a transmission problem but you won't know for sure until you get a scan tool capable of displaying whether the computer is commanding torque convertor lockup and the actual state of the convertor.
Second, thinking about what changes when the engine is cold vs hot, as your problem is only experienced with a hot engine, the first thing that comes to mind is the VCT system. The computer uses an oil temp sensor to know when it can command the VCT solenoids to change cam timing. Cam timing is fixed at full advance until the engine reaches operating temp. Once hot, the computer can change cam timing by up to 60°. I would start by unplugging both VCT solenoids. They are at the front top of both valve covers. The driver side is under the power steering reservoir bracket and will be difficult to get to. Unplugging them will trigger a MIL but will not harm your engine. Drive the truck and see if the problem is still there.
Understand that sometimes the VCT solenoid inlet screens disintegrate and can jam the solenoid. This prevents the computer from controlling the cam position at all and can lead to problems even when the engine is cold. This happened to a friend of mine. Shop told her she needed a new motor. I pulled both VCT solenoids. One had a broken screen with missing pieces, and the other was about to break. Less than $100 for 2 new solenoids and $26 for two new seals and her motor ran perfect again. It would barely idle and had no power before the fix.
Your reported RPMs vs vehicle speed seems really high unless you have 4.30 gears. This leads me to believe that your torque convertor is not locking up as it should be. That could be a transmission problem but you won't know for sure until you get a scan tool capable of displaying whether the computer is commanding torque convertor lockup and the actual state of the convertor.
Second, thinking about what changes when the engine is cold vs hot, as your problem is only experienced with a hot engine, the first thing that comes to mind is the VCT system. The computer uses an oil temp sensor to know when it can command the VCT solenoids to change cam timing. Cam timing is fixed at full advance until the engine reaches operating temp. Once hot, the computer can change cam timing by up to 60°. I would start by unplugging both VCT solenoids. They are at the front top of both valve covers. The driver side is under the power steering reservoir bracket and will be difficult to get to. Unplugging them will trigger a MIL but will not harm your engine. Drive the truck and see if the problem is still there.
Understand that sometimes the VCT solenoid inlet screens disintegrate and can jam the solenoid. This prevents the computer from controlling the cam position at all and can lead to problems even when the engine is cold. This happened to a friend of mine. Shop told her she needed a new motor. I pulled both VCT solenoids. One had a broken screen with missing pieces, and the other was about to break. Less than $100 for 2 new solenoids and $26 for two new seals and her motor ran perfect again. It would barely idle and had no power before the fix.
That being said, I still have the acceleration/bog down issue when the motor is up to operating temperature.
05-27-2015, 11:57 PM
#44
Thanks for this suggestion. I actually did this last night instead of unplugging the cam sensor itself. I unplugged the driver side VCT and it solved half the problem. So far, no more loss of power/stalling in situations where it normally has been. I was usually experiencing this about 3 times a day average. So far over 24 hours it hasn't happened once.
That being said, I still have the acceleration/bog down issue when the motor is up to operating temperature.
That being said, I still have the acceleration/bog down issue when the motor is up to operating temperature.
05-28-2015, 12:50 PM
#46
I don't know if this will help you or not but I was having acceleration issues like you but not stalling or anything and have probably replaced at least what you have if not more and you may have a comletely different problem. I had what I"ll describe as a hesitation/hiccup while driving and hitting the gas at around 2000 rpm now matter how fast I was going but it never did it from a stand still at 2000. It always happened while already moving from lets say 40 mph and up. It turned out to me my MAF sensor. I replaced it out of desperation and never had a code. I cleaned the old one several times and have a new throttle body and did'nt think that was it but I thought what the heck. I got it at Rock Auto, a hitachi brand supposedly OEM for like 50 something bucks and immediatly my hesitation went away. Im still having other issues but the MAF solved this one and Im probably going to post this fix. Im not telling you to throw this part at it. Just giving you my info. Good luck
The following users liked this post:
RickMc (05-31-2015)
05-28-2015, 12:57 PM
#47
Member
Thread Starter
I don't know if this will help you or not but I was having acceleration issues like you but not stalling or anything and have probably replaced at least what you have if not more and you may have a comletely different problem. I had what I"ll describe as a hesitation/hiccup while driving and hitting the gas at around 2000 rpm now matter how fast I was going but it never did it from a stand still at 2000. It always happened while already moving from lets say 40 mph and up. It turned out to me my MAF sensor. I replaced it out of desperation and never had a code. I cleaned the old one several times and have a new throttle body and did'nt think that was it but I thought what the heck. I got it at Rock Auto, a hitachi brand supposedly OEM for like 50 something bucks and immediatly my hesitation went away. Im still having other issues but the MAF solved this one and Im probably going to post this fix. Im not telling you to throw this part at it. Just giving you my info. Good luck
I will say I have noticed my acceleration to be slightly better since I pulled the driver-side VCT connector, but since I pulled it the acceleration issue happens even when the engine is cold instead of only when it's at normal operating temp. So I'm pretty confident at the very least most of my problems with stalling and loss of power have to do with the VCT system. The rest of the acceleration problem could be solved once I get a tuner, but I'll have to cross that bridge when I come to it.
Also for clarification, the other night I pulled only the driver-side VCT connector. Then the next morning I pulled both and noticed no change good or bad, so I plugged the passenger-side back in. That being said, if I do end up replacing the one VCT I may just do them both for GP.
05-29-2015, 08:40 AM
#48
Well, if unplugging one made a significant change in how it ran, I would at least remove both and inspect the screens. You will need two new seals @ ~$13 each. They always get destroyed when you take them out.
05-30-2015, 01:10 PM
#49
Senior Member
Do you have any kind of pictures as to what you are explaining? Not trying to be a burden, but I learn somewhat better if I had a visual reference. Thank you.
