Hit accelerator hard, car nearly craps the bed

[charlatan]

2002 S6.

Yesterday while driving in heavy Chicago traffic, I switched to the left lane, punched it, car reared up to go and just...basically died. It just sputtered and wouldn't accelerate at all. The engine was running but with great difficulty and i would touch the gas and it would have no effect. I pulled over to the side and it was just sputtering. I turned it off. After 6 tries it fired back up and was sputtering, gave it a little gas and it returned to normal.

I was 2.5 hours from home in dense Chicago traffic, on the left side of the road with cars HAULING past me on my way to a show. It could have been awful. Very thankful it fired back up, but now I am freaked the hell out. What the heck could it have been? New fuel pump/filter was added in November. I don't have a VAGCOM to check for a code, (no check engine light came on) but i am going to head up to Autozone in a few to see if they can pull something. I will update this with any findings.

Anyone ever had this happen?

[charlatan]

Well, since I didn't have a check engine light, Autozone said they wouldn't be able to pull any codes...so no idea what happened still. Any ideas?

[rollerton]

I'm guessing there's error *probably. Just not one that is related to emissions or misfire so no CEL. If it drives normal again and you can't duplicate it, I'd say it's just one of those glitches that pucker the rear end.. electrical glitch between MAF and throttle body? Something like that. I've had stuff like that happen once or twice, no explanation; so you just shrug it off and keep going.

[mr_dave]

Definitely get it scanned with a VAG COM and make sure the TCU isn't storing any codes. It could be many things. Or nothing.

[chris86vw]

Since the problem occurred during an attempt to accelerate hard did it start to at first and then die or just never responded at all?

A loose hose connection between MAF and throttle under hard acceleration could cause a condition where airflow bypasses MAF and since the MAF would then see no or little airflow but high throttle and possible temporarily high load it would freak out and you'd have no response. I've seen this before whether it be a loose hose or even a torn one (turbo inlet hose rotting from oil is common on 1.8ts) causes this problem to only occur at higher throttle levels. Depending on engine this may throw a torque monitoring code.

I would check in that area to see if something is up... then if it is and it wasn't a whoops I forgot to secure something may be worth checking the mounts to make sure excess movement didn't pull the hose off.



Also as noted not all faults will turn the CEL light on, even some emissions related will not until it determines the issue is still occurring or happened an additional time. Lack of CEL does not indicate a lack of fault codes.. although some generic scanners will not pick up all the ones that an Audi specific one would, especially in this instance with no CEL.

[JMURiz]

Since the problem occurred during an attempt to accelerate hard did it start to at first and then die or just never responded at all?

A loose hose connection between MAF and throttle under hard acceleration could cause a condition where airflow bypasses MAF and since the MAF would then see no or little airflow but high throttle and possible temporarily high load it would freak out and you'd have no response. I've seen this before whether it be a loose hose or even a torn one (turbo inlet hose rotting from oil is common on 1.8ts) causes this problem to only occur at higher throttle levels. Depending on engine this may throw a torque monitoring code.

I would check in that area to see if something is up... then if it is and it wasn't a whoops I forgot to secure something may be worth checking the mounts to make sure excess movement didn't pull the hose off.



Also as noted not all faults will turn the CEL light on, even some emissions related will not until it determines the issue is still occurring or happened an additional time. Lack of CEL does not indicate a lack of fault codes.. although some generic scanners will not pick up all the ones that an Audi specific one would, especially in this instance with no CEL.

I agree, I had an intake hose leak that caused havoc with my MAF readings...coupled with broken variable intake arms, my car acted possessed until I figured it all out. Everything was great once fixed.