Wonder if ya maybe slipped the belt enough and it threw a misfire and derate for a bit. Should have set a code though I think

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How much fuel? Steep enough to expose the fuel pickup at your fuel level?

 

Tank was nearly full

 

I've never experienced limp mode but that's what it felt like. It didn't die, it just dropped RPM and lots of power and then came right back a few seconds later.

 

I assume you have a Dynojet PV3 tuner since you are running the AA tune. If you do...plug it in and look under historic codes on the PV3. It should still show it there

 

Thanks, I'll do that. I had the PV3 with me and didn't even think to try that.

 

Also, quick check your vacuum lines on the turbo. I had one cracked and went into intermittently limp mode on WOT

 

So I hooked up the PV3 and no codes in current or history

 

I've had the same gremlin pop up and was unable to trace what caused it. No codes/lights, new belt, full tank. It was momentary enough to where I had to bail on the hill climb because I lost momentum to help me that last final bit. Second attempt was no problem. To this day I haven't experienced it again.

 

I'm going to guess it slipped the belt and then cleared.

 

That's what I would've thought but it sure didn't feel like it. It was pulling really hard when the power dropped. I was actually racing an X3 and had him by two cars. I should've let it cool down for a while and tried again to see if the problem persisted but I didn't want to push it and possibly cut my trip short. Plus, China Wall is not a place you want to break down. It's a long ways to camp from there.

 

I've had the misfire codes before and I never felt any slipping. It will detect it before you feel it.
The only other guess I would have is the fuel pump is getting tired and failing when it gets hot?

 

So I finally took the rzr out of the toy hauler today and put the regular tires back on it. Took it around the block and as soon as it came into boost, it did it again and the engine light came on. It's like a switch and the power is cut in half. Otherwise it runs perfectly fine. Drove it home and before I got there the engine light went off and instantly the power jumped up. Checked codes again and nothing.

Curious, what are the symptoms of a failing stock BOV? I'm hearing a kind of whistle when it blows off I didn't hear before.

 

Do you have a datalog to look at like max suggested?

 

Max suggested I look in historic codes which was blank.

Correct me if I'm wrong but wouldn't I need to be datalogging when it happens to be able to see the problem?

I'm ruling out fuel pump for now after seeing how immediate it changes. I feel like this is boost related whether it's a leak somewhere or the BOV itself.

 

If it is not throwing any codes ..which is strange. Then yes you would need to be data logging.
Do some date logs and send them to Mike at AA.
If you have access to another XPT you could swap BOV's it is quick and easy to do.
I would also recommend checking your fuel pressure under load.

 

If it is not throwing any codes ..which is strange. Then yes you would need to be data logging.
Do some date logs and send them to Mike at AA.
If you have access to another XPT you could swap BOV's it is quick and easy to do.
I would also recommend checking your fuel pressure under load.

Can I just leave the fuel pressure tester attached and run it normal while watching the gauge? What pressures should I be looking for ideally?

If it turns out the fuel pump is going bad, is the AEM the best option or is there one that works well that's less expensive?

 

Max's answer seems perfect to me.

I hear the charge tube can crack sometimes too. I've always felt both are more rare, but if you run in a high heat area maybe they weaken.

I think you'd see either the BOV or CT as reduced boost in the log, while you'd likely see an AFR anomoly if it was fuel pressure oriented. Now if Mike would look at it great!

 

I wouldn't rule out the fuel pump too quickly. Usually it will throw a code for most other types of failures but the ecu assumes full fuel pressure at all times so no code is set usually for a weak pump.

 

So I tried logging a run and it only shows speed on the graph. How do you get it to show more than just speed?

Also, I hadn't noticed at the dunes but on a smooth road at steady speed, I could feel minor surging if that makes any sense.

Anyone have an email for Mike to send log files to?

 

I've used this with them:
Aftermarket Assassins <aftermarketassassins@gmail.com>

 

You're loading the tune into the Dynojet powercore software to use? I've not worked on my logs yet, but this is the video I've used to walk me through looking at them before:

 

You're loading the tune into the Dynojet powercore software to use? I've not worked on my logs yet, but this is the video I've used to walk me through looking that them before:

Perfect!! That video shows it perfectly and was exactly what I needed. Thank you!

 

Happy to help. Good luck!

 

Yes you can leave it attached and test it under load . Pressure at idle should be 58 psi +/- 2 psi
Under load / boost you will gain 1 psi per pound of boost ...so you should see under full load about 70 psi
Yes the AEM pump is your best option from what I understand

 

Tested fuel pressure today. Key on only is 58 psi. Cruising is at 54 psi. Full throttle/boost is at 70 and drops to about 63-65 when power cuts off and engine light comes on. Appears to me engine speed is dictating fuel pressure instead of fuel pressure dictating engine speed.

I'm waiting on a reply from Mike to tell me how he wants the log done unless you guys feel it doesn't matter as long as I capture the loss of power.

 

dafish, the fuel pressure tool we discussed in the other thread works fine. I just wrapped a rag around where the gauge threads on and slowly loosened it until pressure was bled off.

 

Sounds like your fuel pump is good then. For a data log just go out and do a couple WOT runs or whatever is necessary to create the problem. Start your data log at 5 mph rolling start.

 

Naturally, I go out and do 6 full throttle pulls to 65 mph, logging each one, and it ran perfect.

 

Murphy's law ... I would again go back to belt slip and clutch settings

 

I thought about that today. I'm at 4-3-3 on the weights but even at that, it jumps to 8750 for a few seconds and slowly comes down to 8600. I may just go to 4-4-4 for the extra belt grip and check where I'm at.

I just don't know if it's belt slip. I went 3 days at Glamis without breaking a belt and it seems to me that if I was slipping the belt, I would've broken one. Maybe I'm wrong.

 

Well their you go... if it's hitting 8700 it's too light on weight for sure and you will definitely get belt slip , or your spider nut is coming loose, but I doubt it .....
Shoot for 8500 max in the first 2 seconds.... and then it should settle to 8350 or 8450 for sand .
I'm starting to see your situation I think ?
The good news is you're making big power and you're just slipping a belt when it gets screaming hot at the top of the Mega hill ......I would try 4/ 4 /3 ...even though it seems heavy it may not be really

Clean / blow out the clutch again and cross hatch the sheaves / de glaze the Primary and Secondary. A new belt cleaned in Dawn soap / Scotch bright and run with some easy miles . Save the old belt for another day after all this is over it will still be usable.

 

Well their you go... if it's hitting 8700 it's too light on weight for sure and you will definitely get belt slip , or your spider nut is coming loose, but I doubt it .....
Shoot for 8500 max in the first 2 seconds.... and then it should settle to 8350 or 8450 for sand .
I'm starting to see your situation I think ?
The good news is you're making big power and you're just slipping a belt when it gets screaming hot at the top of the Mega hill ......I would try 4/ 4 /3 ...even though it seems heavy it may not be really

Clean / blow out the clutch again and cross hatch the sheaves / de glaze the Primary and Secondary. A new belt cleaned in Dawn soap / Scotch bright and run with some easy miles . Save the old belt for another day after all this is over it will still be usable.

That sounds possible but how would this happen when it's cold? When it happened over and over yesterday, it was right out of my driveway. There was no way for the belt to get hot. It happened right away on the first hard acceleration.

I cleaned/deglazed the primary and secondary before going to the dunes. The clutch was as clean as it could be.

Think I should try going back to the stock primary/secondary springs?