LOST JEEPS :: View topic - Bad Map Sensor without completely failing

It also blows big puffs of smoke on take off from a stop light and seems to take a while for the turbo to get going. Once moving the smoke stops.

Do you have a boost gauge?

The TorquePro app + ELM327 blutooth adaptor can give you boost readings as measured directly from the MAP sensor. That could give you an idea if the problem is the turbo or MAP sensor.

It seems to me that your turbo is not putting out enough.

But...

Quote:

It also blows big puffs of smoke on take off from a stop light and seems to take a while for the turbo to get going. Once moving the smoke stops.

I've got this same problem and I live in flat terrain at sea level.
I thought the problem was related to my choice of ECU tune, so I went back to stock.
Same problem.
Changed MAP sensors.
Same problem.

Conclusion:
My taller, heavier, more aggressive, off-road tires take a lot more effort to get moving.
Thus, big puff of black smoke when accelerating from a stop and significantly reduced MPG.

I use TorquePro and monitor boost on my Android tablet.
I can easily get 20-22 psi under moderate acceleration.
So the turbo is working great with no evidence of boost leaks.

Soon I will be installing a actual boost gauge so I can compare its readings to the MAP sensor readings.
(and maybe tweak things a bit :wink:

)

So just to clarify, you also get a nice puff of smoke when leaving from a stop? What about when you are heavy on the throttle climbing a hill or something?

I am running the GDE hot tune so maybe the cut back due to the altitude is just more dramatic than I would have thought because of the turbo's limits

BTW, what is your MAP sensor reading at idle?
When I was traveling through the rockies back in december, I noticed my idle MAP reading was around -1.5 psi vacuum.
Here at home its about +0.5 psi boost.

Is it possible that my MAP sensor could be bad but not completely failed? I have been having an issue ever since I moved out here to Utah from MA where my Jeep is running rich. It seems like anything under half throttle it runs fine. Gas mileage has not been effected and normal driveablility is fine. Where it goes wrong is if you really get into the throttle to climb a hill or make a pass on the highway and it just seems to fall on its face. I get a lot of black smoke out of the exhaust and much less power than when I got my Hot tune in MA. It also blows big puffs of smoke on take off from a stop light and seems to take a while for the turbo to get going. Once moving the smoke stops.

I am just wondering if the MAP could be showing bad readings and causing the ecu to act like its getting more boost than it is.

mass-hole wrote:

1st you can't "run rich" and not have any effect on mileage.

You will loose about 3% of total power per 1000' of elevation and yes your boost and MAF/MAP sensors will also read vastly different the higher you go.

mass-hole wrote:

Well I'm glad our resident CRD expert has chimed in, but no, it's not normal.

Mass-hole, I'm running the same tires as you, but in an even taller size. Same engine tune, factory turbo, no regear. I don't have problems accelerating or getting up hills at altitude. Yes it's slower than it was with factory tires, but it's by no means unreasonable. Maybe your turbo vanes are sticking.

To get some real idea ....can you ask your reader to determine calculated engine load?
That might tell you where you're at. May not too.
But with bigger tyres and altitude it will put a useful value on it.
We then get out of the qualitative to the quantitative.

If your turbo is older, and you have any doubt, you might as well try to spray some of the lube that other have used on the actuator area, and some over cleaner on the inside. Or if there's any noticeable slack on it maybe just replace it if you have $1100 to burn.

I think the actuator should slide smoothly, but have resistance like you're pulling on a spring. If it feels like it's covered in sand or soot then I think you should clean it. Also, make sure that cheap vacuum line doesn't have a tiny leak in it. I had that recently...

Author:	mass-hole [ Wed Aug 26, 2015 12:25 pm ]
Post subject:	Bad Map Sensor without completely failing
Is it possible that my MAP sensor could be bad but not completely failed? I have been having an issue ever since I moved out here to Utah from MA where my Jeep is running rich. It seems like anything under half throttle it runs fine. Gas mileage has not been effected and normal driveablility is fine. Where it goes wrong is if you really get into the throttle to climb a hill or make a pass on the highway and it just seems to fall on its face. I get a lot of black smoke out of the exhaust and much less power than when I got my Hot tune in MA. It also blows big puffs of smoke on take off from a stop light and seems to take a while for the turbo to get going. Once moving the smoke stops. I am just wondering if the MAP could be showing bad readings and causing the ecu to act like its getting more boost than it is.

Author:	flash7210 [ Wed Aug 26, 2015 12:52 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
Do you have a boost gauge? The TorquePro app + ELM327 blutooth adaptor can give you boost readings as measured directly from the MAP sensor. That could give you an idea if the problem is the turbo or MAP sensor. It seems to me that your turbo is not putting out enough. But... Quote: It also blows big puffs of smoke on take off from a stop light and seems to take a while for the turbo to get going. Once moving the smoke stops. I've got this same problem and I live in flat terrain at sea level. I thought the problem was related to my choice of ECU tune, so I went back to stock. Same problem. Changed MAP sensors. Same problem. Conclusion: My taller, heavier, more aggressive, off-road tires take a lot more effort to get moving. Thus, big puff of black smoke when accelerating from a stop and significantly reduced MPG. I use TorquePro and monitor boost on my Android tablet. I can easily get 20-22 psi under moderate acceleration. So the turbo is working great with no evidence of boost leaks. Soon I will be installing a actual boost gauge so I can compare its readings to the MAP sensor readings. (and maybe tweak things a bit )

Author:	mass-hole [ Wed Aug 26, 2015 1:30 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
flash7210 wrote: Do you have a boost gauge? The TorquePro app + ELM327 blutooth adaptor can give you boost readings as measured directly from the MAP sensor. That could give you an idea if the problem is the turbo or MAP sensor. It seems to me that your turbo is not putting out enough. But... Quote: It also blows big puffs of smoke on take off from a stop light and seems to take a while for the turbo to get going. Once moving the smoke stops. I've got this same problem and I live in flat terrain at sea level. I thought the problem was related to my choice of ECU tune, so I went back to stock. Same problem. Changed MAP sensors. Same problem. Conclusion: My taller, heavier, more aggressive, off-road tires take a lot more effort to get moving. Thus, big puff of black smoke when accelerating from a stop and significantly reduced MPG. I use TorquePro and monitor boost on my Android tablet. I can easily get 20-22 psi under moderate acceleration. So the turbo is working great with no evidence of boost leaks. Soon I will be installing a actual boost gauge so I can compare its readings to the MAP sensor readings. (and maybe tweak things a bit ) I have looked at it with Torque pro and I seem to hit a steady 15-16 psi with the occasional higher spike from what I remember. I guess that seems about where it should be since I am at 6500 ft and the air density is about 22% lower than sea level. it seems the general consensus is that the tune hits about 21 psi at sea level so 21 * .78 = 16.4 psi. If you go by what is said around here, the hot tune basically pushes the turbo to its limit at sea level so they must have to cut it back proportionally with altitude. I have removed and reinstalled all boost hoses. I checked most of the tubing for the VNT control and also played around with the actuator to make sure that was not jammed up and it all seems to be ok. So just to clarify, you also get a nice puff of smoke when leaving from a stop? What about when you are heavy on the throttle climbing a hill or something? Maybe you could see if Yeti can increase you boost at idle to see if that helps with the lag. Try to have the turbo spinning a bit more before you ever hit the throttle. I think if I am stopped in D then my throttle position is set by the ECU to about 10% to account for the load of the torque converter according to Torque. I would have to double check that to make sure though. I am running the GDE hot tune so maybe the cut back due to the altitude is just more dramatic than I would have thought because of the turbo's limits

Author:	flash7210 [ Wed Aug 26, 2015 2:32 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
mass-hole wrote: So just to clarify, you also get a nice puff of smoke when leaving from a stop? What about when you are heavy on the throttle climbing a hill or something? Well, there aren't too many steep hills around here, but when I do do a heavy acceleration up a hill there is no noticeable smoke. From a dead stop, if I gently roll into the throttle, there is no smoke. But if I quickly stomp on it, there definitely is. Quote: I am running the GDE hot tune so maybe the cut back due to the altitude is just more dramatic than I would have thought because of the turbo's limits Its probably a combination of things. I'd say that your big tires are definitely making your engine work harder. And combine that with working at a higher altitude...

Author:	flash7210 [ Wed Aug 26, 2015 2:39 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
BTW, what is your MAP sensor reading at idle? When I was traveling through the rockies back in december, I noticed my idle MAP reading was around -1.5 psi vacuum. Here at home its about +0.5 psi boost.

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Author:	mass-hole [ Wed Aug 26, 2015 3:20 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
flash7210 wrote: BTW, what is your MAP sensor reading at idle? When I was traveling through the rockies back in december, I noticed my idle MAP reading was around -1.5 psi vacuum. Here at home its about +0.5 psi boost. I will have to double check but I believe it was in vacuum up here. In Massachusetts it was positive but dont remember the exact value so it seems to confirm what you see.

Author:	f5hunter [ Wed Aug 26, 2015 3:35 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
Check out the last post in this thread by flash7210 viewtopic.php?f=5&t=74785&start=60 "I checked the turbo actuator and vacuum lines and solenoids and all are functioning normally. Boost hoses and intercooler are tight with no leaks. It just seemed that the ECU was dumping too much fuel without adequate boost and therefore producing a heavy thick cloud of black smoke. So I switched back to the OEM 437 MAP sensor and the black smoke has been significantly reduced. Max boost, as read using TorquePro, is now 21.3 psi and I have to push the accelerator pedal a little bit harder to get it there. It seems that, with this tune at least, the difference in the two sensor calibrations is enough to fool the ECU into thinking that the turbo is producing more boost than it actually is. Stock tunes may not have any noticeable effect. Or maybe this was just a fluke and the 845 sensor I was using had some weird problem. All I know is that the difference is significant."

Author:	flash7210 [ Wed Aug 26, 2015 6:00 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
Yeah, I think I over reacted when I posted that True, the MAP sensor change did effect the max boost reading a little. And black smoke was reduced. But it wasnt as significant as I initially thought. This is one of the reasons I am installing a boost gauge. It will hopefully allow me to get accurate boost measurments and compare them to MAP sensor readings.

Author:	mass-hole [ Thu Aug 27, 2015 6:15 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
Being the crazy person I am, I filmed a standing start acceleration with my Xiaomi Yi Camera(GoPro knockoff, check it out) and also simultaneously logged RPM, boost, and Engine Load with Torque so you could see what I am seeing and feeling. https://youtu.be/Gt7ozjhd2ys Engine load is different than throttle position. I believe engine load in Torque pro is the ECU's desired throttle, not what the pedal is actually at. When I start accelerating my foot goes straight to the floor despite what the engine load says. As you can hear/see in the video the engine loads up but doesnt do anything for about 2 seconds, blows a cloud of smoke, then all of a sudden takes off like a rocket. This is basically what it does at every stop light. The smoke while moving isnt so bad, but its way more than I used to have and i think its just the fact that as I accelerate the smoke has more air to dilute into. As for boost, it spikes at the begining to like 15.5 psi and then drops to 14-14.5 psi throughout the rest of the pull. This is roughly 7psi less than sea level which I assume means I am probably making 4/5 the power? You can hear once it shifts into 3rd gear at the end the RPM's are barely climbing because it simply does not have enough grunt. What I want to know from those people out there with GDE's hot tune and at 6500 ft + elevation, is this what you also see, am I paranoid, or is there something wrong here?

Author:	Yeti [ Fri Aug 28, 2015 5:22 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
can you read the kpa at engine off and engine on from the MAP ?

Author:	tjkj2002 [ Sat Aug 29, 2015 6:51 am ]
Post subject:	Re: Bad Map Sensor without completely failing
mass-hole wrote: Is it possible that my MAP sensor could be bad but not completely failed? I have been having an issue ever since I moved out here to Utah from MA where my Jeep is running rich. It seems like anything under half throttle it runs fine. Gas mileage has not been effected and normal driveablility is fine. Where it goes wrong is if you really get into the throttle to climb a hill or make a pass on the highway and it just seems to fall on its face. I get a lot of black smoke out of the exhaust and much less power than when I got my Hot tune in MA. It also blows big puffs of smoke on take off from a stop light and seems to take a while for the turbo to get going. Once moving the smoke stops. I am just wondering if the MAP could be showing bad readings and causing the ecu to act like its getting more boost than it is. 1st you can't "run rich" and not have any effect on mileage. You will loose about 3% of total power per 1000' of elevation and yes your boost and MAF/MAP sensors will also read vastly different the higher you go.

Author:	mass-hole [ Sat Aug 29, 2015 7:57 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
tjkj2002 wrote: mass-hole wrote: Is it possible that my MAP sensor could be bad but not completely failed? I have been having an issue ever since I moved out here to Utah from MA where my Jeep is running rich. It seems like anything under half throttle it runs fine. Gas mileage has not been effected and normal driveablility is fine. Where it goes wrong is if you really get into the throttle to climb a hill or make a pass on the highway and it just seems to fall on its face. I get a lot of black smoke out of the exhaust and much less power than when I got my Hot tune in MA. It also blows big puffs of smoke on take off from a stop light and seems to take a while for the turbo to get going. Once moving the smoke stops. I am just wondering if the MAP could be showing bad readings and causing the ecu to act like its getting more boost than it is. 1st you can't "run rich" and not have any effect on mileage. You will loose about 3% of total power per 1000' of elevation and yes your boost and MAF/MAP sensors will also read vastly different the higher you go. The jeep runs normal below about 50% throttle which is 95% of the driving so the mpg effects are negligable overall. The problems are when i am climbing the 3000 foot of elevation change from salt lake city to park city on i80 and i basically have to floor it the whole way up. tjkj2002 wrote: mass-hole wrote: Is it possible that my MAP sensor could be bad but not completely failed? I have been having an issue ever since I moved out here to Utah from MA where my Jeep is running rich. It seems like anything under half throttle it runs fine. Gas mileage has not been effected and normal driveablility is fine. Where it goes wrong is if you really get into the throttle to climb a hill or make a pass on the highway and it just seems to fall on its face. I get a lot of black smoke out of the exhaust and much less power than when I got my Hot tune in MA. It also blows big puffs of smoke on take off from a stop light and seems to take a while for the turbo to get going. Once moving the smoke stops. I am just wondering if the MAP could be showing bad readings and causing the ecu to act like its getting more boost than it is. 1st you can't "run rich" and not have any effect on mileage. You will loose about 3% of total power per 1000' of elevation and yes your boost and MAF/MAP sensors will also read vastly different the higher you go. Sent from my LG-D850 using Tapatalk

Author:	tjkj2002 [ Sat Aug 29, 2015 10:52 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
Welcome to high altitude with bigger then stock tires and not re-geared.Live with it,it's normal and effects everyone you just notice it more since you just came from very low altitude.

Author:	CATCRD [ Sun Aug 30, 2015 10:51 am ]
Post subject:	Re: Bad Map Sensor without completely failing
Well I'm glad our resident CRD expert has chimed in, but no, it's not normal. Mass-hole, I'm running the same tires as you, but in an even taller size. Same engine tune, factory turbo, no regear. I don't have problems accelerating or getting up hills at altitude. Yes it's slower than it was with factory tires, but it's by no means unreasonable. Maybe your turbo vanes are sticking.

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Author:	mass-hole [ Sun Sep 06, 2015 12:57 am ]
Post subject:	Re: Bad Map Sensor without completely failing
CATCRD wrote: Well I'm glad our resident CRD expert has chimed in, but no, it's not normal. Mass-hole, I'm running the same tires as you, but in an even taller size. Same engine tune, factory turbo, no regear. I don't have problems accelerating or getting up hills at altitude. Yes it's slower than it was with factory tires, but it's by no means unreasonable. Maybe your turbo vanes are sticking. Thats what i thought at first but i removed the vacuum actuator and manually pushed the arm in and out. It had some resistance but not sure what a good actuator should feel like Sent from my LG-D850 using Tapatalk

Author:	Auberon [ Sun Sep 06, 2015 11:55 am ]
Post subject:	Re: Bad Map Sensor without completely failing
To get some real idea ....can you ask your reader to determine calculated engine load? That might tell you where you're at. May not too. But with bigger tyres and altitude it will put a useful value on it. We then get out of the qualitative to the quantitative.

Author:	mass-hole [ Tue Sep 08, 2015 10:46 am ]
Post subject:	Re: Bad Map Sensor without completely failing
Auberon wrote: To get some real idea ....can you ask your reader to determine calculated engine load? That might tell you where you're at. May not too. But with bigger tyres and altitude it will put a useful value on it. We then get out of the qualitative to the quantitative. I used the "engine load" option in Torque on the graph a few posts up, but not sure if that was what you were referring too. Throttle position is not an option for me in Torque.

Author:	Mountainman [ Tue Sep 08, 2015 11:26 am ]
Post subject:	Re: Bad Map Sensor without completely failing
If your turbo is older, and you have any doubt, you might as well try to spray some of the lube that other have used on the actuator area, and some over cleaner on the inside. Or if there's any noticeable slack on it maybe just replace it if you have $1100 to burn. I think the actuator should slide smoothly, but have resistance like you're pulling on a spring. If it feels like it's covered in sand or soot then I think you should clean it. Also, make sure that cheap vacuum line doesn't have a tiny leak in it. I had that recently...

Author:	Mountainman [ Tue Sep 08, 2015 11:31 am ]
Post subject:	Re: Bad Map Sensor without completely failing
Oh, and I agree that the CRD pulls mountain grades without much trouble at all. The beauty of the turbo diesel is that the turbo overcomes most of the elevation power loss, and then you've got the torque to keep you moving. I have thought about going back to the simplicity of my old toyota, but I'm hooked on not gearing down these days...

Author:	Infinite_Karma [ Thu Jan 14, 2016 2:49 pm ]
Post subject:	Re: Bad Map Sensor without completely failing
Hey Mountainman, Any chance you also know the part numbers for the attached vacuum lines/hoses that go to and from the Turbo? I'm trying to track down a replacement for all the vacuum lines/tubes/hoses connected to the Solenoids that route to the turbo. Appreciate any information you have. Thanks again. Sarma Mountainman wrote: If your turbo is older, and you have any doubt, you might as well try to spray some of the lube that other have used on the actuator area, and some over cleaner on the inside. Or if there's any noticeable slack on it maybe just replace it if you have $1100 to burn. I think the actuator should slide smoothly, but have resistance like you're pulling on a spring. If it feels like it's covered in sand or soot then I think you should clean it. Also, make sure that cheap vacuum line doesn't have a tiny leak in it. I had that recently...