Got Fuel Cut?

[JRMSLINEA4]

Tonight is the first time I have gone to WOT in 3rd gear since my reflash and I have the dreaded fuel cut. I did experience a little at the top end of 2nd gear but it is really bad in 3rd gear. Do I now need APR's new fuel pump? I asked the place that did my reflash if there was problems with the 93 program and they said that they have had no fuel cut problems. Does air temp play much of a role in it because it was 17 degrees outside. Thanks for any input.

[VZWalex]

I had similar issues. what ended up being the problem was the my car needed the Cam update.

[Subaru71]

I had similar issues. what ended up being the problem was the my car needed the Cam update.

as in software update? or as in replacing the cam?

[ggg20t]

damnit -- these threads are scaring me. I've talked to a dude from APR, and even a mechanic at my dealer. . he told me my 2005.5 would be fine with the apr 93. WTF.

[juggernaut201]

the dealer lied most of the 05.5's have the old pump and cam

[UFfitz56]

the dealer lied most of the 05.5's have the old pump and cam

Does anyone know when the MY cutoff is for the old cam? Would all 06's have the new cam?

thanks!

[JRMSLINEA4]

I'm hoping Mike or Keith from APR will reply back.

[Grishbok]

i have an 08 b7 and i have fuel cuts on GIAC every so often at high rpm in 4th and 5th gear. typically occuring as power surging between 5-6k rpm. Presumably the fuel pump is unable to keep up with the demand.

[wayneB7]

I'm hoping Mike or Keith from APR will reply back.

So am I because this puts a new light on my impending APR upgrade.

I am not into dicking with the car just to shovel money down the drain. Yes I want the hop / torque gains that I can get from chipping the car and yes I am prepared to update certain components that might be directly related to increased output, but there is a limit to how far I will go before getting a whole different car makes more economic sense.

[D-techniK]

So am I because this puts a new light on my impending APR upgrade.

I am not into dicking with the car just to shovel money down the drain. Yes I want the hop / torque gains that I can get from chipping the car and yes I am prepared to update certain components that might be directly related to increased output, but there is a limit to how far I will go before getting a whole different car makes more economic sense.

x2

[b7ftw]

i have an 08 b7 and i have fuel cuts on GIAC every so often at high rpm in 4th and 5th gear. typically occuring as power surging between 5-6k rpm. Presumably the fuel pump is unable to keep up with the demand.

i have an 05.5 (im gonna safely assume that i have old cam, and until this thread didnt even know there was a difference) and i have exact same experience... its happened only 4 maybe 5 times since getting flashed with GIAC-X about 8 months ago... only happened when on highway at WOT in 5th or 6th...

[artinmoTTion]

JRMSLINEA4,

Do you have a test pipe? Is your program considered stg 1 or 2? I think APR does it a little different than Revo in that regard.

[Six Speed Turbo]

When the APR reps reply to this thread, can one of you PM me. Have a question that I would rather not put on the public forum. Thanks.

[Glassnpowder98]

I got flashed with Revo Stage 2 on Friday and I'm pretty sure I've been getting some fuel cuts in 3rd and 4th gear. Up until now, I always thought fuel cut was a sort of violent bucking action. What I've been experiencing is a little wavering and slight surging in the higher RPM's and it feels like the engine isn't getting enough fuel when acceleration wavers. This is something I hadn't experienced with the Revo Stage 1 software.

[JRMSLINEA4]

JRMSLINEA4,

Do you have a test pipe? Is your program considered stg 1 or 2? I think APR does it a little different than Revo in that regard.

No APR 93 program and thats it. Stage I.

[artinmoTTion]

Thanks, JRM, and...Sir Glassnpowder98, you have a test pipe? With running stage 2 now, I'm just wondering about your thoughts on overall driveability even just around town, and the power curve, without going to an uprated fuel pump. The exhaust would be in place, but I don't plan on getting a test pipe. I know that tips the scales into the fuel cut range for many people, and my mostly non-tracked street car doesn't need to be spewing extra pollution every day. Thanks in advance for your thoughts.

[Glassnpowder98]

I don't have a test pipe and don't really plan on getting one. The drivability of stage 2 is pretty similar to stock except when you get on it, there is a lot more power to be had. It's pretty easy to control when driving in traffic.

Another interesting note is that apparently the dealer has control over the settings of the flash. I always assumed all flashes from each company were the same but apparently with the Revo flash, the dealer sets the parameters of the flash. I'm assuming it would be like using the select plus module that you can purchase from Revo that enables the customer to adjust settings. The guy who installed my flash said he set it up pretty aggressively... So that might be part of the reason I'm getting fuel cuts, because of the aggressive tune.

[IceMole]

There is no cutoff, there are 05.5s with A and B cams. The only way to know is to check, and everyone should be checking the follower anyway even with Bs.

[Kevin2772]

I get it in 3rd gear every once in a while in my 08. Very annoying but only at very high RPMs....would lvoe to know an exact fix to this (hopefully not requiring me to spend a ton more money on my DD.)

[Keith@APR]

The only fix is to make sure your fueling system is healthy.

On a healthy car, none of our products will create any fuel cuts if used as advertised. The addition of a testpipe could potentially demand more fuel in conjunction with our ecu upgrade than the ecu upgrade is calibrated to allow for but our testing never generated any fuel cut issues with a testpipe.

If you've recently installed an APR ecu upgrade and are getting fuel cuts you've more than likely had an issue with your high pressure fueling system for some time that was not evident before as with the oem programming you are not requiring the same amount of fuel. Therefore, eventhough your car seemed to be working fine before you were still on your way to the fueling system degrading to a point that will cause a fuel cut even on the oem ecu.

Awhile back I got HD added to my Directv account as we just purchased a new HD tv. My tv was working great until I started watching HD channels and then it would turn itself off after 2-3 hours of watching. It turns out my tv was overheating due to the demand of watching HD programming. If I watch sd channels it never turns off. I sent my tv back to the manufacturer and they replaced the failed fan switch and now I can watch HD all day long.

That's what the high pressure fueling system reminds me of. As long as I drive in standard def programming, OEM ecu, I never have any problems. However, when I drive in HD, APR ecu, I get fuel cuts. What needs to be corrected? The HD programming or the TV?

[marty was here]

The only fix is to make sure your fueling system is healthy.

On a healthy car, none of our products will create any fuel cuts if used as advertised. The addition of a testpipe could potentially demand more fuel in conjunction with our ecu upgrade than the ecu upgrade is calibrated to allow for but our testing never generated any fuel cut issues with a testpipe.

If you've recently installed an APR ecu upgrade and are getting fuel cuts you've more than likely had an issue with your high pressure fueling system for some time that was not evident before as with the oem programming you are not requiring the same amount of fuel. Therefore, eventhough your car seemed to be working fine before you were still on your way to the fueling system degrading to a point that will cause a fuel cut even on the oem ecu.

Awhile back I got HD added to my Directv account as we just purchased a new HD tv. My tv was working great until I started watching HD channels and then it would turn itself off after 2-3 hours of watching. It turns out my tv was overheating due to the demand of watching HD programming. If I watch sd channels it never turns off. I sent my tv back to the manufacturer and they replaced the failed fan switch and now I can watch HD all day long.

That's what the high pressure fueling system reminds me of. As long as I drive in standard def programming, OEM ecu, I never have any problems. However, when I drive in HD, APR ecu, I get fuel cuts. What needs to be corrected? The HD programming or the TV?

cliffnotes is we need to switch to standard programming? but hd becomes the norm in the end of feb what then?

ps i see what u did here with the analogy, but i just got confused

[JRMSLINEA4]

The only fix is to make sure your fueling system is healthy.

On a healthy car, none of our products will create any fuel cuts if used as advertised. The addition of a testpipe could potentially demand more fuel in conjunction with our ecu upgrade than the ecu upgrade is calibrated to allow for but our testing never generated any fuel cut issues with a testpipe.

If you've recently installed an APR ecu upgrade and are getting fuel cuts you've more than likely had an issue with your high pressure fueling system for some time that was not evident before as with the oem programming you are not requiring the same amount of fuel. Therefore, eventhough your car seemed to be working fine before you were still on your way to the fueling system degrading to a point that will cause a fuel cut even on the oem ecu.

Awhile back I got HD added to my Directv account as we just purchased a new HD tv. My tv was working great until I started watching HD channels and then it would turn itself off after 2-3 hours of watching. It turns out my tv was overheating due to the demand of watching HD programming. If I watch sd channels it never turns off. I sent my tv back to the manufacturer and they replaced the failed fan switch and now I can watch HD all day long.

That's what the high pressure fueling system reminds me of. As long as I drive in standard def programming, OEM ecu, I never have any problems. However, when I drive in HD, APR ecu, I get fuel cuts. What needs to be corrected? The HD programming or the TV?

I had no fuel cuts on the stock program.What would you do next? Could cam wear be the problem if so is there a way to check?

[Keith@APR]

cliffnotes is we need to switch to standard programming?

ps i see what u did here with the analogy, but i just got confused

Honestly, if you don't want to address the inherent cam issue alot of B7 A4 owners are going to experience, don't buy an A4. If you already have and want to avoid addressing the inherent cam issue as long as possible, don't drive or mod it. If you decide to address the problem head on drive your A4 and/or mod it and expect to deal with the fuel cuts when they come because regardless of what you do, you are more than likely going to have to address it at some point.

I hate to council against buying any VAG product but sometimes even the best make mistakes. If you have the old cam you are going to get a fuel cut eventually, its just a matter time.

To be proactive, you can check your cam lobe to determine what revision you have and then try and have it warrantied.

To avoid a costly repair if you are out of warranty or to catch it early enough so you can avoid extensive damage resulting in increased downtime, you can check your cam follower frequently and replace it as it shows sign of wear.

Here's a document listing the differences in cams and what the follower is and how to access it.

http://www.goapr.com/Audi/support/fs...stallation.pdf

I've seen reports of worn followers on the newest cam revision as well so I recommend that you inspect your follower regardless.

[marty was here]

so fuel cut is inevitable no matter what?

[Keith@APR]

so fuel cut is inevitable no matter what?

Technically speaking, on the bad cam yes. The hardening isn't strong enough and is going to wear eventually no matter what. Once the hardening on the lobe is worn, the cam follower gets its coating sanded off and there you go, fuel cut. It seems to be possible for the bad cam to wear anywhere from 8k miles to 60k or so miles of use. I'm sure there are bad cams that have lasted even longer or perhaps will never fail but I imagine they are the minority.

Its also possible to lose lift from the cam lobe hardening wear and get fuel cuts on a perfectly healthy cam follower due to the loss of lift. We've measured cam lobes that were almost worn to a whole mm which doesn't seem like much but its something like a 5% loss in lift which is pretty significant.

The jury is still out as to whether or not its inevitable on the new cam lobe as it is doing much, much better but I still see the random report of a failed follower with the new cam.

If I owned a B7 A4 2.0T FSI I would campaign the Audi dealership to replace the cam for the newest one and then I would check my follower every 5-10k miles. This will ensure no issues whatsoever. Its too bad the follower has to be dealt with like a maintenance item but that is the only way to avoid costly repair if out of warranty.

[artinmoTTion]

Keith,

This is very helpful, and I completely agree with you. As you know, the dealers won't put the labor into investigating the cams until the car starts to throw codes. It seems pretty blatantly obvious to me that Audi is headed for another class action lawsuit, but is preferring to wait and see rather than be proactive on this, which is a shame for a company that likes to tout its engineering leadership....

Not totally understanding the mechanics of the system (but helped along by yours and others' posts), is there the possibility that some ingenious aftermarket engineering company like APR and others could design a better replacement for the stock setup?

[Blarg]

So let's say that my car has the "A" cam and I notice that the follower is worn. I replace it and it wears down again, I replace it again. Eventually, the cam will wear too much that a new follower won't "fix" the issue. When this happens, the only options out of warranty are:

1. replace the cam with the "B"
2. buy a follower that is thicker/higher like the KMD follower

[Keith@APR]

Keith,

This is very helpful, and I completely agree with you. As you know, the dealers won't put the labor into investigating the cams until the car starts to throw codes. It seems pretty blatantly obvious to me that Audi is headed for another class action lawsuit, but is preferring to wait and see rather than be proactive on this, which is a shame for a company that likes to tout its engineering leadership....

Not totally understanding the mechanics of the system (but helped along by yours and others' posts), is there the possibility that some ingenious aftermarket engineering company like APR and others could design a better replacement for the stock setup?

Schrick makes a cam set for the 2.0T FSI that includes the extra lobe for the fuel pump. We are testing it currently and will let everyone know what we find out.

[Keith@APR]

So let's say that my car has the "A" cam and I notice that the follower is worn. I replace it and it wears down again, I replace it again. Eventually, the cam will wear too much that a new follower won't "fix" the issue. When this happens, the only options out of warranty are:

1. replace the cam with the "B"
2. buy a follower that is thicker/higher like the KMD follower

The state of your cam lobe will determine if you replace it after you inspect it. Replacing the follower continually will buy you time but the bad cam is the root of the issue and you won't resolve the problem until you replace the cam. This is if the cam lobe is worn. It will chew through followers pretty quickly and as the lobe wears, you will lose pump lift or pumping capacity regardless of how often you replace the follower.

[Kevin2772]

So why am I experiencing this on a 2008 A4 that was delivered in January of 08 (directly after it was built since it was built to order.) Basically you're saying that if we dont want to deal with the cam wear we cant chip the car?

Also, what is the exact way to fix this as I dont have time to spend with my car on a lift. Is there anything out there that will fix the problem and it'll be done?!

[Grishbok]

its the way audi decided to engineer it. Chipping the car gives you performance gains, but by adding that stress, you amplify existing issues. All of the cam issues will happen, its inevitable. Being chipped merely brings the issue to light faster and being more aware of this puts you ahead of the game.

I have a 2008 A4 and am experiencing this, I am hoping someone will put up a step by step write up on how to check for cam lobe wear and follower wear and what they look like with pretty pictures. I would like to see someone do a write up for dummies.

Im sure alot of us are saying "If i was staring at cam B, i would not know if its worn or not and Im pretty sure im not the only one. I would like to see some pictures of a healthy cam next to a worn cam so i know what to look for and how to check it, step for step"

[Keith@APR]

So why am I experiencing this on a 2008 A4 that was delivered in January of 08 (directly after it was built since it was built to order.) Basically you're saying that if we dont want to deal with the cam wear we cant chip the car?

Also, what is the exact way to fix this as I dont have time to spend with my car on a lift. Is there anything out there that will fix the problem and it'll be done?!

If you have the improperly hardened cam lobe whether your chip the car or not you will have to deal with cam wear.

If you have the new revision cam, you should have nothing to fear but it is a good idea to check the health of your cam follower periodically just in case.

A chip isn't going to increase the wear or affect the fueling system in any way. However, because a chip requires more fuel, if your cam lobe is wearing you will experience low fuel pressure sooner than on the oem programming.

For example:

When the cam lobe wears the first operation affected is the amount of lift the cam lobe is able to stroke on the fuel pump piston. This loss of lift and therefore fuel pump capacity increases over time until the cam follower is eventually destroyed.

With oem programming the loss of lift has to be greater than with an ecu upgrade. So, you've got a ticking time bomb either way and with an ecu upgrade you could expect to be able to catch the issue sooner as you will experience running issues at a lesser amount of cam lobe wear and eventual follower destruction. This is not always the case but as a general rule.

If the new cams continue to hold up then you will never experience any of this but I would still inspect the cam and follower periodically whether you mod the car or not.

[Glassnpowder98]

its the way audi decided to engineer it. Chipping the car gives you performance gains, but by adding that stress, you amplify existing issues. All of the cam issues will happen, its inevitable. Being chipped merely brings the issue to light faster and being more aware of this puts you ahead of the game.

I have a 2008 A4 and am experiencing this, I am hoping someone will put up a step by step write up on how to check for cam lobe wear and follower wear and what they look like with pretty pictures. I would like to see someone do a write up for dummies.

Im sure alot of us are saying "If i was staring at cam B, i would not know if its worn or not and Im pretty sure im not the only one. I would like to see some pictures of a healthy cam next to a worn cam so i know what to look for and how to check it, step for step"

You're in luck... AWE has included the TSB and how to check for it in their HPFP installation guide. Maybe some day we can have a cam lobe/follower check party! I pretty sure I'll be getting their fuel pump with my tax return, so I'll definitely be checking for wear when I install it. I'm just not real excited about removing the pump with all of the pressure it builds up...

http://www.awe-tuning.com/media/pdf/...FP_Upgrade.pdf

[Grishbok]

*plays Queen - Under Pressure*

[Glassnpowder98]

*plays Queen - Under Pressure*

While I scream bloody murder and have like 130 bar pressure shooting gasoline into my veins... It's gonna be a paaarty

[Keith@APR]

You're in luck... AWE has included the TSB and how to check for it in their HPFP installation guide. Maybe some day we can have a cam lobe/follower check party! I pretty sure I'll be getting their fuel pump with my tax return, so I'll definitely be checking for wear when I install it. I'm just not real excited about removing the pump with all of the pressure it builds up...

http://www.awe-tuning.com/media/pdf/...FP_Upgrade.pdf

I think there might be a little bit more info in this document as well:

http://www.goapr.com/VW/support/fsi_...stallation.pdf

Early B7 owners should be aware of the lack of Schroeder valve for releasing fuel pressure.

[Glassnpowder98]

Keith, thanks for that link. It's nice to know the major tuning companies available to the Audi crowd are interested in keeping their customer's cars running right and don't just care about their bottom line.

[Blarg]

So out of warranty what would an independent shop charge just for labor to put in a new cam?

[JRMSLINEA4]

Small update. I ran my car last night and did 3 pulls from 2500rpm-6000rpms in 2nd and 3rd gear and got "0" fuel cut. Whats changed? The temp was 10 degrees warmer and I was 1/2 a quart low on oil and I changed over to Shell 93 off B.P. 93. In fact the car felt stronger than ever. Did any of those things make a difference, probably not. But I did get a letter in the mail from Audi on "top tier gas stations" and shell was listed and I'm not sure if B.P. was. Not sure what to make if this but I will keep tracking it.

[JRMSLINEA4]

Update.. Its been a few weeks and I still get no fuel cut in 2nd and 3rd gear but I have it big time in a 4th gear pull. Last night was my first time trying 4th gear. Could it be my stock DV? and not fuel cut? No check engine light and I am going to see if I have any stored codes.