After much work, 2.7t still violently surging around 40 mph
#1
10-15-2016, 07:45 PM
After much work, 2.7t still violently surging around 40 mph
Hello,
Reconditioned my last car, and it was stolen and totaled the the next day after it was finished. Twice...long story. It's dead. anyways...thats why I'm on the budget de la ramen for repairs...
We were broke, picked up a 2002 Allroad w the 2.7t. 164k.
Surging at about 40, severely...Only under normal pedal. Super hard pedal or super light it's kinda ok .
Runs acceptably in limp.Shifting normal in limp mode. Recently stopped being able to start unless it was ultra cold, and was randomly dying.
Finally replaced both o2 sensors which had codes(upstream), coolant temp sensor, both camshaft position sensors, mass air flow sensor, and a blown front strut airbag thingy.
It ran normalish after i pulled out. Then, it started reving to about 5500 before shifting, and again, around forty miles an hour, violent jerking...a bit less violent, and more frequent now. It's behaving like it's getting an extra 40 horsepower from boost, then midway into that deciding it would rather not. I made it the six miles home. Light smokes from near where the silver y pipe feeds into the throttle body.
All this work and now it's doing the same thing, at higher revs.
Where do i look next?
I'm not a mechanic or even close. But now i have to be. Please help me.
Btw, had the tranny refilled(not flushed) at an audi place. Diagnostics there and my old honda shop. Both the audi shop and the honda guys i used before said the tc and tranny seemed "prestine".
Prior to the honda(last car, stolen one) i owned only audi and vw. I've never had such a stubborn or terrifying vehicle issue...
Reconditioned my last car, and it was stolen and totaled the the next day after it was finished. Twice...long story. It's dead. anyways...thats why I'm on the budget de la ramen for repairs...
We were broke, picked up a 2002 Allroad w the 2.7t. 164k.
Surging at about 40, severely...Only under normal pedal. Super hard pedal or super light it's kinda ok .
Runs acceptably in limp.Shifting normal in limp mode. Recently stopped being able to start unless it was ultra cold, and was randomly dying.
Finally replaced both o2 sensors which had codes(upstream), coolant temp sensor, both camshaft position sensors, mass air flow sensor, and a blown front strut airbag thingy.
It ran normalish after i pulled out. Then, it started reving to about 5500 before shifting, and again, around forty miles an hour, violent jerking...a bit less violent, and more frequent now. It's behaving like it's getting an extra 40 horsepower from boost, then midway into that deciding it would rather not. I made it the six miles home. Light smokes from near where the silver y pipe feeds into the throttle body.
All this work and now it's doing the same thing, at higher revs.
Where do i look next?
I'm not a mechanic or even close. But now i have to be. Please help me.
Btw, had the tranny refilled(not flushed) at an audi place. Diagnostics there and my old honda shop. Both the audi shop and the honda guys i used before said the tc and tranny seemed "prestine".
Prior to the honda(last car, stolen one) i owned only audi and vw. I've never had such a stubborn or terrifying vehicle issue...
#2
10-19-2016, 10:42 AM
Update on the car
I replaced the torn vacuum lines to the Fuel Pressure Regulator on top of the rail, the diverter valves and subsequently got it running.
It ran ok for a day, then once the temperature was over 70f, it proceeded to throw codes of being rich on both banks. Surging stops in cold weather.
The MAF i got was a U-Pull thing, so it's suspect.
After I got home last night, the car sat 20 mins and wouldn't start. Fuel pump appears to be doing its thing though.
I am told Fuel relay, Fuel pressure regulator, evap purge valve? Black biscuit (PCV) can all cause the no warm start problem. I am told the boost valve can cause the surging.
Can anyone please help me narrow down the issue so that I am not just throwing money at the problem?
Thanks guys and gals
It ran ok for a day, then once the temperature was over 70f, it proceeded to throw codes of being rich on both banks. Surging stops in cold weather.
The MAF i got was a U-Pull thing, so it's suspect.
After I got home last night, the car sat 20 mins and wouldn't start. Fuel pump appears to be doing its thing though.
I am told Fuel relay, Fuel pressure regulator, evap purge valve? Black biscuit (PCV) can all cause the no warm start problem. I am told the boost valve can cause the surging.
Can anyone please help me narrow down the issue so that I am not just throwing money at the problem?
Thanks guys and gals
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