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Symptoms of bad 3 bar MAP sensor?

Turboflash

Turboflash

Lifetime Member
Joined
Mar 18, 2019
Messages
2,508
Location
Southern MN
Country
USA
Snowmobile
'17 ZR9000 Ltd. 137 - PEFI Stage 4
I thought I'd ask all you expert tuners here what are classic symptoms of a MAP sensor not performing as designed?
Erratic idle AFR? Erratic WOT AFR? Erratic idle RPM? Erratic AFR at part throttle cruise?
I believe I've read some here on TY have had to get their MAP sensors replaced by both TD and Hurricane? Why? What were they not doing or what were they doing that made them bad?
Thanks guys.
 

Boost pressure readings erratic on the logs. Spiking up and down.
 
Turboflash said:
I thought I'd ask all you expert tuners here what are classic symptoms of a MAP sensor not performing as designed?
Erratic idle AFR? Erratic WOT AFR? Erratic idle RPM? Erratic AFR at part throttle cruise?
I believe I've read some here on TY have had to get their MAP sensors replaced by both TD and Hurricane? Why? What were they not doing or what were they doing that made them bad?
Thanks guys.
Click to expand...

TF here is my experience:

Key on, engine off, boost on the dash should read anywhere between .2-.8 lbs of boost. This is normal. If your boost reads outside these parameters change the sensor.

Mine read 0 and although sled ran great, it would not boost high enough at WOT. Big tune would only boost 16.9 lbs. Changed map sensor and all back to normal.
 
I have had 3 different 3 bar map sensors.

The original gap sensor was the one with the aluminum adapter for the boost line and it worked perfect for 2 seasons then it started to show zero boost until up into mid rpm, the sled was running OK but just seemed lazy compared to normal.
The second sensor I got read almost 1 psi boost when it was not even running and the sled ran poorly...data logs also were a bit erratic on boost readouts and it was so bad that I only used it for one day and then I put the original one back in and sent it back to Hurricane and Dave exchanged it.
The third sensor Hurricane sent me is working and indicating great and the sled is back to its normal performance.
 
Wondering the same thing. Sled acted up before I left on a trip. Would Only start touching throttle(cant load video)roll over sputtering showing 400/500rpm holding key on.(even up to temp) no codes. I took the lines off the map sensor etc and blew them out...sled started ran perfectly. Put 500 miles on in -20temp busting trails in 30cm snow..couldn't get the hand off the key quick enough everytime to start. Came home Friday night, gonna take the sled to the fire hall to service it as I have 1000miles on now..exact same issue...i did the same thing again with the map sesor lines etc..started and ran perfectly..any thoughts? Talked to a few figured 3bar is going south. Seems to do it after sitting a few days. Never noticed any water/condensation in hoses or on sensor.
 
rev them up said:
Wondering the same thing. Sled acted up before I left on a trip. Would Only start touching throttle(cant load video)roll over sputtering showing 400/500rpm holding key on.(even up to temp) no codes. I took the lines off the map sensor etc and blew them out...sled started ran perfectly. Put 500 miles on in -20temp busting trails in 30cm snow..couldn't get the hand off the key quick enough everytime to start. Came home Friday night, gonna take the sled to the fire hall to service it as I have 1000miles on now..exact same issue...i did the same thing again with the map sesor lines etc..started and ran perfectly..any thoughts? Talked to a few figured 3bar is going south. Seems to do it after sitting a few days. Never noticed any water/condensation in hoses or on sensor.
Click to expand...
That does not sound like a Map Sensor issue but more like condensation and resulting frozen/plugged vacuum/signal limes to the boost or wastegate solenoids.
Get the sled into a warm place for a couple days and blow out all the lines to the solenoids...also if not already done remove the line from the airbox to the waste gate solenoid as per Yamahas service bulletin.
 
rev them up said:
Wondering the same thing. Sled acted up before I left on a trip. Would Only start touching throttle(cant load video)roll over sputtering showing 400/500rpm holding key on.(even up to temp) no codes. I took the lines off the map sensor etc and blew them out...sled started ran perfectly. Put 500 miles on in -20temp busting trails in 30cm snow..couldn't get the hand off the key quick enough everytime to start. Came home Friday night, gonna take the sled to the fire hall to service it as I have 1000miles on now..exact same issue...i did the same thing again with the map sesor lines etc..started and ran perfectly..any thoughts? Talked to a few figured 3bar is going south. Seems to do it after sitting a few days. Never noticed any water/condensation in hoses or on sensor.
Click to expand...
Check this out...

ty4stroke.com

Plugging the wastegate solenoid vent?

The tuned one was having low boost issues that he could not resolve. I got him to drop the winder off and this is what I found. I still need to go through a few things but I am pretty this was his issue Without a doubt that was the issue of low boost. The dealer didn't know squat about how...
ty4stroke.com ty4stroke.com
 
If you watch your boost on your dash it usually shows itself being doing weird things.
 
sideshowBob said:
That does not sound like a Map Sensor issue but more like condensation and resulting frozen/plugged vacuum/signal limes to the boost or wastegate solenoids.
Get the sled into a warm place for a couple days and blow out all the lines to the solenoids...also if not already done remove the line from the airbox to the waste gate solenoid as per Yamahas service bulletin.
Click to expand...
This is very important info and should be a sticky at the top
 
sideshowBob said:
That does not sound like a Map Sensor issue but more like condensation and resulting frozen/plugged vacuum/signal limes to the boost or wastegate solenoids.
Get the sled into a warm place for a couple days and blow out all the lines to the solenoids...also if not already done remove the line from the airbox to the waste gate solenoid as per Yamahas service bulletin.
Click to expand...
Thanks for the info. Wish i could upload the video. Sent it to td tonight and my local guys..he believes map sensor. I never looked at boost all that much but sled seemed to run a fine. I never seen any condensation in the lines or the map sensor...both times it happened the sled sat for a couple days. Sled only started and ran right after i took the lines/map sensor off and blew in them, sled did it before loading to go away..ran perfect for 500miles, came home and sat for a few day's then repeated it self and only started and ran correctly after once again removing sensor/lines. Rpm was 600/700 trying to start.
 
Video is on fb on the yamaha sidewinder tech group. Tried dropping link still cant get it.
 
Checking for moisture or oil in lines the other day, and found none. But during this process I noticed that the 3 bar sensor once removed, has that aluminum adapter for the boost line, and that is only held in place with an O ring!

I am having no issues with boost, but just noticing how easy this adapter could come off, so I added a few drops of glue to mate the adapter top to bottom of the sensor!

What do you think, good or bad?
 
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