Evening all
I require your assistance with a rough running issue.
Intermittently I experience issues when first turning the ignition over, it will chug a couple of times & then die. After turning it over a few more times it will catch & run almost normally, just with reduced boost.
Next it will loose all boost when under heavy load (ie flooring it), generally between 2.5k & 3k rpm. When this occurs it is extremely lumpy & backfires once or twice. Then it hits 3k+ rpm & the boost suddenly surges back.
I've had it on VAGCOM a couple of times but all it's showing up are the symptoms, not the cause.
The 1st time it threw up that it was running lean (I could have figured that out without the computer) plus the god awfull 17705 pressure lose code.
Yesterday I was coming back north up the M1 & it did it BIG time when going up the big hill leading to J37. I was happily cruising at around 70-75 at the bottom of the hill, by the time I got to the top I was doing 40ish the CEL came on & it was coughing & spluttering. I got off at 37 & turned it off, thinking I'd lost a hose. However everything was fine under the hood.
After 10 mins I turned it over & it was fine for another 10 miles or so then started again.
Got it on VAGCOM again this afternoon, with the following results:
17704 - Temp sensor (but it's not overheating)
17705 - Pressure loss (checked everything again, no splits anywhere)
17854 - O2 sensor after the cat (So shouldn't affect the running)
Since this first started its had the timing belt, water pump, plugs, 2 coils, an oil filter & oil change (ie a major service).
Initially i thought it could be the fuel filter, but its intermittent & a restriction wouldnt be. So now I'm thinking it could be the lamba sensor before the cat that's throwing some strange messages back to the ECU.
Anyone had any similar experiences? If so; what the hell was it???
Any help would be greatly appreciated!