He-he-hesitating

[Juice]

Yesterday I may or may not have been chasing an Audi S4 up an on ramp, but what definitely happened was the car hesitated under power when going up hill. At first I didn't conclude that it was up hill, but I tried reproducing it a few times after it happened, and it didn't happen again until another up hill area. I'll see if I can reproduce it on video, but until then, dafuq?

Thanks in advance.

[Juice]

To start off, I'm probably going to replace the fuel filter. Cheap fix if that's it, and it could probably use it anyway. I can't find my log book since I moved, so I don't know when it was done last.

[mike P71]

I had very similar simptoms recently and it turned out to be a coil. The first thing I would do is change the fuel filter then ck the coils. Good luck

[RF Overlord]

It only happens going uphill? Sounds like a fuel delivery issue...

[fastblackmerc]

Definitely change the fuel filter.

[03sport007]

If its fuel related be careful under boost. Do you have a wideband?

[Juice]

If its fuel related be careful under boost. Do you have a wideband?

I don't.

It's on the list though.

[justbob]

I don't.

It's on the list though.

Keep playing with that fire and it will be a new block on the list as well... It is your engines LIFELINE.

[Juice]

I figured as much. I don't drive it hard that often, so it wasn't high up on the list of priorities.

Would this one do the trick?

http://www.amazon.com/AEM-30-4100-UE...=pd_sim_auto_1

[03sport007]

I figured as much. I don't drive it hard that often, so it wasn't high up on the list of priorities.

Would this one do the trick?

http://www.amazon.com/AEM-30-4100-UE...=pd_sim_auto_1

I think that's one I have. Have you done any data-logging? Does it happen every time you go up a hill or just sometimes? Still running the stock fuel pump?

[Juice]

That was the first time it happened, so the car is parked until I figure out what's up. I bought a fuel filter, but I haven't put it in yet.

I haven't done any data logging, I don't know how. The two times I got it to do it were both up hill and under medium to heavy power, it didn't do it just cruising.

Stock pump with a bap.

[03sport007]

I'm no expert so take what I have to say with a grain of salt:

I find it hard to believe that the gravity of going up a hill is putting enough extra stress on the fuel system(Pump or Filter) that your loosing enough pressure that the motor starts to hesitate. If that's true I would think you've been on the raged edge for awhile. How many miles on the pump and filter?

I'd really like to see what your FP duty cycle, Fuel Pressure and A/F is doing.

Do you have a SCT Tuner? If so you its pretty easy to Data-log.

[Juice]

I'm pretty sure it's the stock pump, so 83k. I don't know about the fuel filter, like I said in my post I don't know where my log book is, so I don't know the last time it was replaced.

I have an SCT tuner, I'll check that out tomorrow. I'm going to replace the fuel filter first though. I'd prefer not to drive it too much if there is some other issue.

[Blackened300a]

I'm no expert so take what I have to say with a grain of salt:

I find it hard to believe that the gravity of going up a hill is putting enough extra stress on the fuel system(Pump or Filter) that your loosing enough pressure that the motor starts to hesitate. If that's true I would think you've been on the raged edge for awhile.

Agreed. I think it's coil related since they can be finicky and start breaking up under a load. Even just one coil can cause a huge hesititation.

[Juice]

Alright, thanks. This coil concept is foreign to me, so I'll do a little digging.

I tried to data log the fuel pump today and hit a bump, so that's on hold til I fix my screw up. I did change the fuel filter though, so if nothing else, that's one thing eliminated.