Help! Fuel Rail Oscillation- CP3 pump/Stage 3 Tune

All,

I wanted to share my experience and am hoping someone can assist me in trouble shooting this situation. I installed a CP3 pump. Car runs well at low throttle/RPM. Step on it and I get this....




I've contacted Malone and they are reviewing. I've changed the fuel rail regulator, metering valve and now finally swapped the pump out. I'm at a loss of where to turn next. Malone has many cars with my setup and no problems.

Any suggestions on what to look at next are appreciated.

Respectfully,
Travis

Did this problem emerge when cold weather hit? If so, your filters may be getting restricted with wax or ice.

It began when I first installed the CP3 pump. (The first one..). This was months ago. At the time we thought it was bouncing off the EGT limiter. I had my stage 3 tune defueled somewhat and the EGT's are good and there was no change to the rail pressure situation.

I'm out of ideas on where to turn next. I'm thinking about running a small container of diesel directly to the pump to eliminate any fuel starvation issues pre hpfp.

Well we know that there is no calibration in your software for the CP3 to run as it should.
Usually stage 1-2 goes ok without any calibration.
Bobby and Ruben may have different opinion on this, if they wanna share with us.

The pump you have is not regenerated or revised/tested in bosch center, so there is no warranty on it.
I will anyway change it at my own expense. Better to have a happy client.
Since then i only installed about 50 kits with revised pumps and all work flawlessly.

Anyway making the cp3 work as it should with high pressures and big IQ is not so easy. I dont think many tuners achieved that.

I only know of one other big power Cp3 car that runs smoothly, other than mine.
Bobby Singh did my tuning.

Thanks for your responses. The thing is, I'm not running big power. I should only be around 200 horsepower with my setup.

Mac, while I appreciate the offer for a new pump and will gladly accept it, I don't believe changing the pump for a third time will make any difference unless there is something different about the Bosch reman.

Both pump 1 and pump 2 installed made pressure. It must be a controls or controls hardware issue.

Respectfully,
Travis

Have malone give you a stage 2 tune, then you can see if it's the tune or the hardware.

Have you tried pulling the supply hose off the filter and powering the in-tank pump? Maybe there is a restriction somewhere. I'd also make sure no fuel hoses are kinked. My stage 3 malone tune and CP3 work great together.

Thanks. Going to check both. Tune and possible fuel restriction.

You tried 2 pumps on the car and all manifest the same problem? Then its not the pump but something else somewhere.

My runs perfectly smooth but there is room from improvement.
When i get maximum 50bars of +- arond 2200bar i will be happy. Right now is more like +80 -100
Maybe is time for Malone to test some calibrations on the pump.

A friend is saying that the original file i got from Mark Malone is different from european cars.

Mac can you please explain further? What does that mean?

I would expect that the stock tune for North America would be somewhat different.

Respectfully,
Travis

Looks to me you need to adjust PID map for PCV. I would test with disconnected FCA, then it has full fueling from pump side. If still its same, then PCV pid needs adjustment.
Ofc it would be nice to rule out feed problems, but i doubt there is the case.

Well, I think we can rule the tune out as the issue. Last night I took a log and the first pull had the oscillation and the rest just magically didn't. Took a log at lunch today and it is perfect.



I did a 3rd gear pull and it was a one tire fire all the way. Smooth acceleration.

I was so happy. But at the same time worried because the problem wasn't answered. Then on the ride home the oscillation returned. So at least this proves my hardware and software can work properly.

My next guess is to remove the PolarFIS and triple check all wiring connections. It has been brought to my attention that the PolarFIS could be interfering somehow. An easy check. Is anyone out there in TDI world running a common rail with a stage 3 tune and CP3 pump with a PolarFIS? How does it work?

This has been making me absolutely crazy. I will savor the triumph when this gremlin is finally defeated...

I want to thank everyone who has taken the time to help me sort this out. Owain from Malone, Andrew Dreossi, Macradiators, and my local tuner Kevinski.

I kind of feel like I've got the superfriends to help me. As somebody who is wading into uncharted territory, it's great to have the support of these folks.

Let's see what happens when I pull the FIS and pull on the wires...

Respectfully,
Travis

The Polar FIS can't cause an impact.

All the Polar FIS is, is a way to interact with the onboard systems and display data.
In exactly the same way that VCDS works (that's why if you have a Polar FIS you cannot have the display pages open when you are using VCDS).

Just because you don't get rail p issues in one log doesn't mean the tune is OK.
It could be a hardware or software issue, but I can guarantee the Polar FIS is not causing an issue.

Xjay, I appreciate your comments. I'm to the point where I need to eliminate any possible variables.

It must interact on some level as it can do things like mirror dip etc. I have heard that they can go bad and leave you stranded. Also, if the tune was flashed via the ODB port, it's through that device. Could it affect? I don't know? I'm out of ideas except to remove it, recheck all connections and reflash my tune.

Respectfully,
Travis

Again, just want to eliminate any possible variables.

xjay1337 said:

The Polar FIS can't cause an impact.

All the Polar FIS is, is a way to interact with the onboard systems and display data.
In exactly the same way that VCDS works (that's why if you have a Polar FIS you cannot have the display pages open when you are using VCDS).

Just because you don't get rail p issues in one log doesn't mean the tune is OK.
It could be a hardware or software issue, but I can guarantee the Polar FIS is not causing an issue.

Click to expand...

Saturating the CANBUS can certainly cause some wonky stuff. I've seen it on other applications before where so much data was being requested by the CAN logger that it totally screwed up how the engine ran.

This would not be the first time I've personally seen a Polar FIS cause a serious problem.

Didn't get a chance to pull the PolarFIS, but I turned it off (switched to MFI screen) on the way into work today and the car ran without the oscillation.

Not sure if it would have an impact on rail pressure, but since I've installed the first CP3, I've always had the rail pressure displayed on the PolarFIS.

Oh, I hope this is the answer... When running properly and driven hard, it's a one tire fire. Wavetrac is in the mail!

Kevinski4 said:

Saturating the CANBUS can certainly cause some wonky stuff. I've seen it on other applications before where so much data was being requested by the CAN logger that it totally screwed up how the engine ran.
This would not be the first time I've personally seen a Polar FIS cause a serious problem.

Click to expand...

As I said, I have had no issues with Polar FIS. I've had mine installed for 3 years from stock right through to my level of tune now.

When we first installed the CP3 on my car we also had large rail pressure variations (similar to what OP has logged and shown).

Once tuned suitably my rail pressure is very stable and it does not impact whether I have the Polar FIS enabled, disabled or up my butt

It's exactly like running the car with VCDS connected.

Been driving with the PolarFIS turned off and seems to be doing good.

Hard to identify unless I'm driving the car hard and that can make for an interesting ride to work.

Going to pull the PolarFIS, drive more, log and restore my tune to full fuelling early next week.

More info to come in the next few days.

I don't want to jinx it, but all the anecdotal evidence is all pointing to the PolarFIS. It's really too bad, because it is a neat gadget. I think I heard that you can update the firmware. Not sure if that would make a difference or not. Either way, I don't want to use a device that could potentially restrict or interrupt communication amongst the components.

Respectfully,
Travis

Told you polar fis was giving me issues, so i took it down.
VCDS connected to the car also did not work ok with polarfis, communication issues, . I will put it back after i am done, maybe.

Mac, Polar FIS and VCDS will not work simultaneously.

All you need to do is tab off the Polar screen on the MFD.

It's like accessing databases .... only so many connections allowed.

You can update the Firmware yes. If you haven't done so I'd probably try that.
If it is giving you issues then it's due to a FAULTY unit.

Good to know, i will try to update it although i got it 1 year ago, maybe not that old FW.

Well, back to the drawing board...

Removed PolarFIS this morning and went for a ride. Here is a snip from the log..



The oscillation was there just about every time, but I did capture one pull without the oscillation. Then after I stopped the log, and turned off VCDS, I did have one nice smooth pull.

PolarFIS has been ruled out. I did unplug the metering valve and it appears okay. When in installed the new plug I may have the wires crossed? Could that create an issue? You wouldn't think it would be intermittent though...

Must be a bad connection or broken wire?

Damn this is infuriating... any thoughts appreciated.

Travis

I had the same problem with that pump. I installed a new! valve (Bosch) on that pump and from this point i had no more oscillations.

I've literally tried 3 different genuine Bosch metering valves. Two used and one brand new.

Thing that gets me is that sometimes it works perfectly. Mostly it does not.

HamBam, were your oscillations only at wide open throttle like mine or was it in a greater range?

Thank you for your comments.

Travis

Do I need to suggest the tune again?

I had an issue on a test tune on my stock CP4 pump
Pushing big IQ to see how far the stock pump would go.

If I drove normally, it was fine, and flat out -

If I drove at a steady 2000rpm for a few seconds, in 2nd gear and then accelerated, I would get low rail P.
If I avoided doing that particular "thing" it would be fine.

I suspect you have an issue in your tune, but the particular parameters that are required for it to fail are not being achieved every time.
This is where simply asking on a Forum for help is not a good idea. You need to work with a trusted tuner if possible.

If Malone did your tune and they are not in a location that you can drop the car off they should be asking you to log using VCDS, and give them data.

Yes, tune is next. Malone has been assisting and we will be de-tuning to stock w/deletes to verify tune is not the issue.

But Xjay, if tune is the issue, then why does everyone else with the same hardware and identical tune have no issues?

I have been logging and sending them my logs. Mostly group 21. Can you suggest any other groups to log that would explain the situation better?

Respectfully,
Travis

travis45 said:

Yes, tune is next. Malone has been assisting and we will be de-tuning to stock w/deletes to verify tune is not the issue.

But Xjay, if tune is the issue, then why does everyone else with the same hardware and identical tune have no issues?

I have been logging and sending them my logs. Mostly group 21. Can you suggest any other groups to log that would explain the situation better?

Respectfully,
Travis

Click to expand...

If you dig a little deeper, there are many people with various CP3 kits running into issues, especially if they are tuned. I know personally of 4 cars in Europe with rail pressure problems on cp3 kit.

And even so, every tune is (or should be) different. So there could be many things different between two tuned cars. Maybe some cars have minor nuances due to old hardware/injectors/lift pump that can cause slightly different results.

I think it's the tune. Malone can assist , I'm sure.

Took another log tonight which includes the control deviation from group 19. Not sure if it sheds any light on how to pinpoint the tuning tweeks or not. But it is some more data. It looks to me like the over pressurization of the rail occurs first, and then there is an overcompensation which leads to the oscillation...