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Picture of the MAP sensor. Make sure the hose is connected at both ends. Also the hose tends to clog up a bit where it connects to the engine intake so check that out. Easy way to check the MAP is to unplug the three wire plug and take it for a spin. You will get a check engine light but it will go away when plugged back in. If it runs much better then either the hose is bad or the sensor is bad. Map sensors seldom fail.
Also easy way to check the ICP is to unplug it. Once again you will get a check engine light but if the truck runs better then the ICP might be bad. On these sensors use only OEM as aftermarket sensors tend to not work or cause issues. Computer will use internal tables for desired values so what you see might not be the actual value.
Okay so kind of embarrassed to say what the problem was but at least I learned something new about the truck lol turns out the MAP sensor work ALOT better when the hose is attach to it and the intake .... long story short the truck finally has boost. But after driving it for a while I noticed the idle will change on and off to a little bit more of a lope. Also when it sounds like it’s loping the motor seems to be a lot more responsive and rev a lot faster. Sounds like a bad icp sensor IMO.
I’m going to put my scan tool on it tomorrow and wee what the icp numbers are doing now that I have boost. The ICP sensor was replaced about 6 months ago but now that I think about I think it was from Napa . Has anyone ever had any problems with the ICP sensor from Napa?
Okay so kind of embarrassed to say what the problem was but at least I learned something new about the truck lol turns out the MAP sensor work ALOT better when the hose is attach to it and the intake .... long story short the truck finally has boost. But after driving it for a while I noticed the idle will change on and off to a little bit more of a lope. Also when it sounds like it’s loping the motor seems to be a lot more responsive and rev a lot faster. Sounds like a bad icp sensor IMO.
Don't be embarrassed, You are not the first one to make the mistake. MAP hose kinda gets in the way when doing maintenance and it's easy to forget to reconnect it. You can unplug the ICP and if the lope goes away it could be the aftermarket sensor. This is the way it works:
With ICP unplugged the PCM will detect that and throw a check engine light. It will however allow the truck to run using internal tables on what should be. In other words the computer will command the IPR to open a certain percent and expect a certain ICP value. Since the ICP is disconnected the value shown on the scanner will be the guess. Don't get caught up in the "why are my values different" syndrome with it unplugged.
Don't be embarrassed, You are not the first one to make the mistake. MAP hose kinda gets in the way when doing maintenance and it's easy to forget to reconnect it. You can unplug the ICP and if the lope goes away it could be the aftermarket sensor. This is the way it works:
With ICP unplugged the PCM will detect that and throw a check engine light. It will however allow the truck to run using internal tables on what should be. In other words the computer will command the IPR to open a certain percent and expect a certain ICP value. Since the ICP is disconnected the value shown on the scanner will be the guess. Don't get caught up in the "why are my values different" syndrome with it unplugged.
im gonna try to simulate the loping again and then try unplugging the icp, I’ll let you know what I find. Thanks for the help guys!
not sure if I plugged the MAP sensor in. One question I had was, what is the importance of the AIT sensor because I pulled a code for a bad AIT. Never read much on here about either sensor. I’ll search up the MAP sensor and see.
IMO the AIT sensor has nothing to do with fueling during normal driving, Its main purpose in life is to help control the EBPV (exhaust back pressure valve), if you still have it or possibly unplugged, to help warm up the engine quicker on cold mornings. Some will disagree with me on this. Since you have the 6637 filter that sensor was inserted into the old OEM filter box. Most just leave it connected to the wiring harness and stick it beside the 6637 or in the fender area. I think it's a two wire plug and if it's missing just get another one and the code will go away.
Your thread made me think about this but I don't know if it will help. When I had the loping idle an oil change fixed it. My truck was mostly sitting for quite a while before I bought it. The oil looked new so I thought it was good. I short changed it anyway, just for peace of mind and it fixed my idle. Old oil doesn't make good hydraulic fluid, aerates, and your injectors suffer for it.
Your thread made me think about this but I don't know if it will help. When I had the loping idle an oil change fixed it. My truck was mostly sitting for quite a while before I bought it. The oil looked new so I thought it was good. I short changed it anyway, just for peace of mind and it fixed my idle. Old oil doesn't make good hydraulic fluid, aerates, and your injectors suffer for it.
Your ICP sensor is biased . at WOT the ipr should be 60 to 65 % . The IPR only responds to what is called for , it does not report . It could be sticking . Unless its the TPS the engine is not responding to what is called for . THe PCM responds to the TPS by calling for oil pressure based on it . If it does not respond it may be the ICP reporting higher than expected pressures . If that is the case the IPR will remain open longer
Your thread made me think about this but I don't know if it will help. When I had the loping idle an oil change fixed it. My truck was mostly sitting for quite a while before I bought it. The oil looked new so I thought it was good. I short changed it anyway, just for peace of mind and it fixed my idle. Old oil doesn't make good hydraulic fluid, aerates, and your injectors suffer for it.
I did a oil change when I did the motor swap, and the oil still looks almost like a honey color and it’s not sooted up at all. I also put a little bit of sea foam in the oil too when I did the oil change.
Originally Posted by Action4478
Your ICP sensor is biased . at WOT the ipr should be 60 to 65 % . The IPR only responds to what is called for , it does not report . It could be sticking . Unless its the TPS the engine is not responding to what is called for . THe PCM responds to the TPS by calling for oil pressure based on it . If it does not respond it may be the ICP reporting higher than expected pressures . If that is the case the IPR will remain open longer
okay well other than the numbers I posted, I’m in the truck now and got it to do the loping again and when I unplugged the ICP it didn’t seem to help or make a difference much at all. It idles decently and then seems to change rpm and shake a little bit aggressively, then calms down and goes back to the choppy idle. It only does it when it’s warmed up, if I turn it off it fires right up every time.
Originally Posted by Hussler
IMO the AIT sensor has nothing to do with fueling during normal driving, Its main purpose in life is to help control the EBPV (exhaust back pressure valve), if you still have it or possibly unplugged, to help warm up the engine quicker on cold mornings. Some will disagree with me on this. Since you have the 6637 filter that sensor was inserted into the old OEM filter box. Most just leave it connected to the wiring harness and stick it beside the 6637 or in the fender area. I think it's a two wire plug and if it's missing just get another one and the code will go away.
A local diesel shop told me that an unplugged AIT could cause defueling... didn’t sound right to me.
So the truck slowly stalled on me driving it in my neighborhood. My fuel guage said I had a quarter tank left but I flipped the dual tank switch and then she fired right up. Could my guage just be wrong and all the problems I’m having are just from it being low on fuel?
No sea foam or any additives in the oil. Our PS diesels don't like them, just use approved diesel oil only. With the HP oil injector system they can cause foaming and poor running performance. On the fuel level issue there is a foot that can drop off in the tank and when at or below 1/4 tank fuel starvation can occur.
. Has anyone ever had any problems with the ICP sensor from Napa?
