Polaris RZR Forum - RZR Forums.net banner

21 - 36 of 36 Posts

·
Premium Member
Joined
·
515 Posts
@White Lightning 19
I cant remember do you have any engine mods or all stock? Does it stumble or do anything weird when you are cruising at 40 before the light comes on ?
Engine wise I'm still all stock.
Runs great as long as you vary the speed up and down, but hold it steady for very long and all the sudden like you lost a cylinder. Shut it off turn key to acc.and let pump and gauges cycle then will run great.
Main reasoning behind tuner thought is they seem to calm down the sensors including misfire from a belt slip. Fuel pump o-ring if nothing else it's good cheap preventive maintenance but can also cause misfiring codes if I'm understanding fuel threads.
Like I mentioned before, I'm pretty fortunate so far as I can run around the mountains and you can't tell a thing is wrong all weekend, it's mostly running around town it's a PITA.
 

·
Premium Member
Joined
·
515 Posts
Screams of TPS to me. is it difficult/costly to replace? Is there a quality inline fuel filter In it anywhere?

It seems recurrent, even chronic, but not absolute. That should rule out the muffler, and you’d think valves too. almost has to be something electrical in the fuel/Ecu/sensor path

I was saw something like this twice In cars I’ve owned. Once was a TPS, and the other was a connector pin in the harness that had backed out and was making intermittent contact. That last one took a donor wiring harness to test with to find...
Reoccurring, chronic and not absolute is the tough part of it.
ECU's controlling more and adding more sensors is a double edged sword. One side you can program to get max efficiency from a motor, other side is throws a bunch of monkeys into the pot.
 

·
Aspiring Perfectionist
Joined
·
4,685 Posts
Discussion Starter #23
Current update:

Flashed my ECU back to the stock tune, plugged it in his machine, went through the ECT learn procedure (several times), and his machine barely even starts and idles with my ECU, couldn't even drive it, very inconsistent idle between 950 & 1400 RPM, tried to get a couple logs even though I couldn't drive it, All TMAP sensors show consistent and seemingly correct data, correct Barometric pressure, Pre/Post TB temps seems accurate, no erratic data. TPS sensor is all over the place tho, partly due to trying to keep the machine running, but even so, doing a horrible job at it. TPS shows 25-60% trying to maintain an idle, and is only somewhat responsive to pedal input, this held true even after we got the engine warmed up. Pedal Sensor doesn't show anything suspicious, I monitored it in realtime with the DJ software and it's spot on to how far the pedal is pressed. For comparison, my machine at idle shows about 6--10% TPS.

Also, as another interesting caveat to this nightmare....I plugged his ECU into my machine, idles and runs fine, plugged his ECU back into his machine, idles fine, and acts as before, possible to drive, anything past half throttle just bogs the engine. Even with the weird behavior of the ECU swaps, with what we found and were able to deduce, ECU is 95% ruled out as a possibility.

Swapping throttle bodies will be the next step in the diagnosis, it's a slow process as both he and I have been busy as hell the last couple weeks and haven't had much time to mess with it.

Spent too much time messing ECU's to have time to further look into intake leaks, but I haven't ruled those out yet, it does have several characteristics of a Post - TB intake leak, but the behavior of the TPS has me more concerned at this particular point, especially since the TPS has been a somewhat rare, but possible cause for the trouble code for others.

@dafish It's killing me lol, it's a compound issue and matter of coincidence to the bad fuel situation it seems at this point, which lead us down a logical, and correct diagnosis path to begin with, but it seems that we've been fighting two unrelated causes that both have the same effect when it comes to symptoms and DTC's.

@White Lightning 19 Checking fuel pressure would still be my first suggestion in diagnosis for this code, the occurrence we're fighting isn't typical for every other appearance of the code that I've looked into, ours is playing out to be just a freak situation, I'd still say that fuel system issues would be the cause of the code at least 80% of the time. As far as a tuner goes, the powervision is once of the handiest diagnostic tools available to us as consumers for the machine, outside of the benefits of the actual tune itself, it's still worth the $ just for the monitoring capability. I would kill to get my hands on the Polaris Digital Wrench software/system, but that seems a bit out of possibility from what I've found out ( If anyone knows how.....I'd love for you to PM me with the details 😁 )
 

·
Registered
Joined
·
968 Posts
This screams TPS harness/plug or TMAP harness/plug/sensor to me. You are describing almost exactly what mine was doing.
 

·
Aspiring Perfectionist
Joined
·
4,685 Posts
Discussion Starter #25
This screams TPS harness/plug or TMAP harness/plug/sensor to me. You are describing almost exactly what mine was doing.
The plugs are all good, no signs of any issues with the wiring. All pigtails and plugs look fine, The TMAP sensors all behave normal, even while wiggling the wires with it running and logging. The TPS shows no change for the better or the worse when I wiggle the wires with it running.
 

·
Registered
Joined
·
968 Posts
Physically mine also looked fine. It was crazy because I could wiggle the heck out of them and they would do nothing. With the TMAP I ended up using a long pry bar to reach it. If I placed just the right pressure in just the right position it replicated the problem. I replaced both the TMAP harness and sensor and it's been fixed ever since. BTW, I'm referring to the TMAP on the charge tube, since there are I believe 3. One in the intake tube, one on the charge tube, and one on the intake manifold.
 

·
Aspiring Perfectionist
Joined
·
4,685 Posts
Discussion Starter #27
Physically mine also looked fine. It was crazy because I could wiggle the heck out of them and they would do nothing. With the TMAP I ended up using a long pry bar to reach it. If I placed just the right pressure in just the right position it replicated the problem. I replaced both the TMAP harness and sensor and it's been fixed ever since. BTW, I'm referring to the TMAP on the charge tube, since there are I believe 3. One in the intake tube, one on the charge tube, and one on the intake manifold.
I'll put it back on the possibility list and look into it once again the next time we mess with it

Did you splice in from a donor OEM harness, or what plugs did you use? you said you did the TPS harness as well?
 

·
Premium Member
Joined
·
327 Posts
Did it throw any more codes when your ECU was plugged in?
 

·
Aspiring Perfectionist
Joined
·
4,685 Posts
Discussion Starter #30
Here's a screen cap from the logs, this is with my ECU is his rzr:



For those that aren't familiar with the DJ log setup... top graph, red line, is accelerator pedal position, green line is Throttle position. Bottom graph, red line is requested a/f ratio, green line is Engine RPM ( x1000 )

So requested a/f is all over the place, idle RPM is all over the place, TPS is all over the place.

Again, with his ECU, the rzr will idle fine, with mine, it will not. My RZR works fine with either ECU.

I'm just posting this in the event it sparks some epiphany for anyone else, Throttle body, intake/exhaust leaks, and further examination of the wiring are the next planned steps.
 

·
Registered
Joined
·
968 Posts
When my throttle body harness was bad, my TPS was literally all over the place in comparison to the PPS . Yours is still kinda relative to PPS. Based on what I went through and saw with mine, I would really be looking at the TMAP. Not to be a broken record. I'll see if I can find one of my logs.
 

·
Aspiring Perfectionist
Joined
·
4,685 Posts
Discussion Starter #32
When my throttle body harness was bad, my TPS was literally all over the place in comparison to the PPS . Yours is still kinda relative to PPS. Based on what I went through and saw with mine, I would really be looking at the TMAP. Not to be a broken record. I'll see if I can find one of my logs.
Don't worry about being a broken record lol, and don't think I'm trying to push you away with my replies, purely just discussion, I certainly appreciate the input

Here's the TMAP data from the same log, obviously the pressure in the intake tube would be expected to change with the throttle body doing who knows what, but I'm not sure if the TPS is the cause or effect either

653905


653906
 

·
Registered
Joined
·
968 Posts
Here's a screen cap from the logs, this is with my ECU is his rzr:



For those that aren't familiar with the DJ log setup... top graph, red line, is accelerator pedal position, green line is Throttle position. Bottom graph, red line is requested a/f ratio, green line is Engine RPM ( x1000 )

So requested a/f is all over the place, idle RPM is all over the place, TPS is all over the place.

Again, with his ECU, the rzr will idle fine, with mine, it will not. My RZR works fine with either ECU.

I'm just posting this in the event it sparks some epiphany for anyone else, Throttle body, intake/exhaust leaks, and further examination of the wiring are the next planned steps.
 

·
Premium Member
Joined
·
515 Posts
I'm not familiar with the Power Vision yet but it definitely shows how erratic that machine is running.

Thanks for sharing all your knowledge and diagnostics your doing. Sucks your buddy is going through this mystery but it's great knowledge going out into the community.
I've been taking our RZR back n forth to the job site due to it's a total mud pit right now, so it gives me time to try different scenarios. I'm thinking you've hit mine right on the head. We are getting the same code but that's about the only thing that they have in common.
My original intention for a tuner was to feed my need to feel what dialed in 200hp is like in these toys. After seeing your above post it's clear that the expanded understanding and knowledge I'll gain of the technical side of these systems that make them run so good will be priceless.
 

·
Registered
Joined
·
24 Posts
Do you have a way to check the live signal coming from the crankshaft sensor. I used to be an automotive mechanic and I guess my next approach would be to get a live scope and start going through the sensor one at a time and look at the raw data not what the PCM thinks it’s seeing especially since they both work good on your machine. Scan tool data isn’t always that accurate. It’s best to see live raw data if you can
 

·
Aspiring Perfectionist
Joined
·
4,685 Posts
Discussion Starter #36
Do you have a way to check the live signal coming from the crankshaft sensor. I used to be an automotive mechanic and I guess my next approach would be to get a live scope and start going through the sensor one at a time and look at the raw data not what the PCM thinks it’s seeing especially since they both work good on your machine. Scan tool data isn’t always that accurate. It’s best to see live raw data if you can
I cannot, the limited live data I can see comes through the CAN bus. Only way to see anything further is with the Digital Wrench software, which is a dealer only system, and even that still pulls from the CAN bus, just much more in depth.
 
21 - 36 of 36 Posts
Top