Hi all,

I'm having trouble diagnosing my problem, but here's what I have: 04 TT Quattro with a Neuspeed Air intake, Forge Diverter Valve and Revotek ECU upgrade. I've been getting engine misfire warnings and check engine light every so often, but with more frequency recently. At first it was cylinder 2, reset the check engine light ran fine then came back on but in cylinder 4. It usually comes on and happens when I run hard and fast. over 5000 rpm, but with my foot to the floor. If I casually just let the engine rev up over 5000 it's fine. When it happens the whole car shutters and generally feels like I'm going to die. (To be scientific about it.)

I have replaced all the coil packs with STI (Manufacturer) coil packs, the plugs are only maybe 20,000 miles old and I had the timing belts done at 86,000 I have about 92,000 now. Also in the past few days I've noticed from time to time when I'm driving I will lose power, like I'm almost out of gas and sucking up the last bit at the bottom of the tank. Doesn't always happen, maybe 4 times in 2 weeks. the first time I was driving and lost power, I could put my foot to the floor with no increase in rpm, but if I took my foot off the gas, down shifted and accelerated it seemed to correct itself.

Do you think the misfires are related to a fuel issue? Maybe a clogged filter or a bad fuel pump? Could it be clogged injectors? I really don't think it's actually an electrical problem as much as a possible fuel delivery problem. (I always use premium gas, about 5000 miles ago I did add a little seafoam to the gas tank, could that have broken up sediment at the bottom of the tank and clogged up the filter and lines?)

Has anyone seen this before? I've been trying to figure it out for the past 2 weeks to no avail.

Thanks all!

Jay 

Previously Jason Rogers wrote:

Hi all,

I'm having trouble diagnosing my problem, but here's what I have: 04 TT Quattro with a Neuspeed Air intake, Forge Diverter Valve and Revotek ECU upgrade. I've been getting engine misfire warnings and check engine light every so often, but with more frequency recently. At first it was cylinder 2, reset the check engine light ran fine then came back on but in cylinder 4. It usually comes on and happens when I run hard and fast. over 5000 rpm, but with my foot to the floor. If I casually just let the engine rev up over 5000 it's fine. When it happens the whole car shutters and generally feels like I'm going to die. (To be scientific about it.)

I have replaced all the coil packs with STI (Manufacturer) coil packs, the plugs are only maybe 20,000 miles old and I had the timing belts done at 86,000 I have about 92,000 now. Also in the past few days I've noticed from time to time when I'm driving I will lose power, like I'm almost out of gas and sucking up the last bit at the bottom of the tank. Doesn't always happen, maybe 4 times in 2 weeks. the first time I was driving and lost power, I could put my foot to the floor with no increase in rpm, but if I took my foot off the gas, down shifted and accelerated it seemed to correct itself.

Do you think the misfires are related to a fuel issue? Maybe a clogged filter or a bad fuel pump? Could it be clogged injectors? I really don't think it's actually an electrical problem as much as a possible fuel delivery problem. (I always use premium gas, about 5000 miles ago I did add a little seafoam to the gas tank, could that have broken up sediment at the bottom of the tank and clogged up the filter and lines?)

My '03 had a similar issue as your "running out of gas" problem.  It did not throw any codes but it would act like it was out of gas.  Turned out to be a faulty break pedal switch.  I had noticed that sometimes when I left my car in the garage the brake lights would stay on.  The Tech told me that if the brake pedal switch come on, the computer thinks you are trying to stop the car and will cut off the gas.  They replaced the $5 switch (it's what the pedal hits when it is disengaged) and the problem has not returned. 

I've also read of the cam chain tensioner going bad and causing the problems you describe.  This will cause the engine to throw a error code but I'm not sure which one. 

Has anyone seen this before? I've been trying to figure it out for the past 2 weeks to no avail.

 

Hi Jason

Have you checked the mass air flow (MAF) - I had a problem with mine before and got a swap out one for cost from Audi ....

Joe

Dublin Ireland

Previously Jason Rogers wrote:

Hi all,

I'm having trouble diagnosing my problem, but here's what I have: 04 TT Quattro with a Neuspeed Air intake, Forge Diverter Valve and Revotek ECU upgrade. I've been getting engine misfire warnings and check engine light every so often, but with more frequency recently. At first it was cylinder 2, reset the check engine light ran fine then came back on but in cylinder 4. It usually comes on and happens when I run hard and fast. over 5000 rpm, but with my foot to the floor. If I casually just let the engine rev up over 5000 it's fine. When it happens the whole car shutters and generally feels like I'm going to die. (To be scientific about it.)

I have replaced all the coil packs with STI (Manufacturer) coil packs, the plugs are only maybe 20,000 miles old and I had the timing belts done at 86,000 I have about 92,000 now. Also in the past few days I've noticed from time to time when I'm driving I will lose power, like I'm almost out of gas and sucking up the last bit at the bottom of the tank. Doesn't always happen, maybe 4 times in 2 weeks. the first time I was driving and lost power, I could put my foot to the floor with no increase in rpm, but if I took my foot off the gas, down shifted and accelerated it seemed to correct itself.

Do you think the misfires are related to a fuel issue? Maybe a clogged filter or a bad fuel pump? Could it be clogged injectors? I really don't think it's actually an electrical problem as much as a possible fuel delivery problem. (I always use premium gas, about 5000 miles ago I did add a little seafoam to the gas tank, could that have broken up sediment at the bottom of the tank and clogged up the filter and lines?)

Has anyone seen this before? I've been trying to figure it out for the past 2 weeks to no avail.

Thanks all!

Jay