Boost Problem With My Rs4s?

[A31-RB20]

Hey all!

Hope someone can help me out here. Ive got a problem with my Stagea after driving for a short while.

I tried searching for a topic that was on here a while ago that was a similar problem to what I have but had no luck.

Ok, quick run down.

I posted a topic a few weeks ago about my intake pipe sucking closed. I noticed my car drove like crap after 15-20mins in the warm weather. Boost would drop down from a constant 0.55 bar down to 0.30 or 0.4 bar max.

The car felt really sluggish and sounded like it was struggling. I presumed it was the intake pipe so I made up the $10 mod and had a 10cm cut of 3" stainless fitted inside the intake pipe.

Well, that wasnt the problem. I since fitted a boost tee, running 0.70 bar, again it drops down to 0.50 bar now after a short while of driving.

From what I can gather, I believe the ECU is retarding the timing as It feels really sluggish and doesnt want to move at all.

Anyone have any ideas on this?

Its starting to piss me off as the car will be running really well then come to a stop take off and its a slug.

Any help would be appreciated!

Thanks all, Dan

[QWK32]

Do you have access to a consult cable and software, or know how to check error codes yourself. Consult would be better because then you could also check what values the ecu is getting. You say its after about 15min, so I'd be checking the engine temp signal going to the ecu, it's not the same sender as the one on the dash. If this is faulty it could be sending the ecu into safe mode.

[66yostagea]

Have you tried resetting the ecu?

[32TAXI]

My 'S' had similar probs - surging on boost - no codes - heaps of fuel - black tailgate

Seems the 'S' has very sensitive ecu and 'rich and retards' on any sort of boost increase!

Fitted, tweaked & tuned a R34GTT PowerFC @ 11psi = great midrange + good economy & no black tailgate

206awhp Too!

Edited November 17, 2009 by RED513

[KiwiRS4T]

If you follow the top hose from the radiator down to the place where it joins the block you will see two sensors - the one with two wires goes to the ecu and the one with one wire goes to the temp guage.

You could try swapping the ecu with someone else but better still if you have a Series 2 neo then get a nistune fitted and get a tune from a good tuner.

[scotty nm35]

And check the solder connections on the airflow meter? Seems unusual it changes between lights, almost like a loose connection or dry solder joint.

[A31-RB20]

Ok quick update. I cleaned up the two connections on the thermostat housing and did the boost solenoid mod. Boost seems to be staying at a max of 0.70 bar. Took it for a good drive and doesn't seem to be playing up.

I'll drive it to work tomorrow, 41 degrees should bring out any issues!

Thanks again for all the help!

[Raysboostin]

pretty sure they r all like that from the factory. mines exactly the same. im fairly certain its the ecu turning the boost down after the engine has reached operating temp. i got no idea why its like that. but ive spoken to others that also had the prob with thiers and in every case it went away once an EBC was fitted

edit: it also goes away if u bypass the factory boost soleniod, but the stock turbo doesnt like 14psi and the engine will hit fuel cut anyway. i know mine did!! but i only had it bypassed for 10mins to confirm my theory. DONT RUN UR CAR WITH THE SOLENIOD BYPASSED!!

Edited November 19, 2009 by Raysboostin