Boost problems again

[Acidburn]

could be a leak from the pipes that go to the diff.

[shark_90]

OK I've just got back (and used about £10 fuel in 10 minutes!).

General boost through midrange at WOT is around 1 bar
Boost at redline from 3rd - 4th is lower, say 0.6-0.7 bar
Only time I see boost very high is if I put it in 6th at 1800rpm and give it WOT - then it goes up to around 1.4 bar

Does that sound normal?

The other thing to note is that when I was in 6th at WOT I could obviously hear more of what was going on in the car due to the lower engine speed.. and I could hear a distinct hiss from the back of the car. Bear in mind I have no back seats.. is the hiss likely to be the fuel pump wanging a load of fuel through or is it likely to be a boost leak (in the back?!) or some other boost related thingummy?

[Greg_S]

That sounds about right.

[shark_90]

I'll go out in the car and do some test runs - so I should look for 1.1 - 1.2 in overboost, does at matter at what RPM?

I'll do some boost at redline tests too.

[S2central.net]

Stock you should see 1.1 - 1.2 bar in overboost mode on an ABY - about 15 seconds worth if you floor it quickly in 4th or higher. Normal max boost is about 0.8bar...

If you are reliably seeing 1.4bar in the midrange with overboost, then it maybe has a chip already - or a big old WG spring perhaps ?

MOre importantly what is boost at the redline if you've been caning it from 3rd or 4th at 1.4bar and onto the next gear (or two for warp speed) ?

Paul

[shark_90]

Off the back of this.. can anyone say what boost levels should be seen and when? Since I fitted my gauge at the weekend I've been out in the car a couple of times (just to see if the boost gauge worked OK) and I'm usually seeing around 0.9bar boost, but if I put it in 3rd or 4th at lowish revs and go to WOT I get peaks of 1.4 bar or so.

[dest]

Thanks for all the replies, thats given me alot of things to check

Just been out and spent an hour checking as many vacuum hoses as I can see, checked the one into the ecu and where it was t'd for the guage too, everything seemed ok.
Then checked and replugged in all the connectors for the coil loom, they are all nice and tight.
I then made sure all the coils were seated ok on the plugs, and realised they seemed quite loose.... then it dawned on me; I hadnt cut down the rings on the rubber section
They are now visibly seated abit deeper, alot tighter to pull off, and feel like they are making a better connection with the plugs.

So, then took it out for a drive, and gave it some boost, 5 times in a row it gave 9psi through the whole rev range in 3rd and 4th with no holding back or hesitation.
It also felt smoother off the boost too

I guess 9 is alittle low, but its better than none! Any ideas as to that?

The real test will be on the way to work later on some DC

Fingers crossed, the coils not making a good connection was the problem!

Now then, whos going to lend me some money for a homefry

[Acidburn]

Might be worthwhile getting it healthchecked at MRC as iirc that does not cost much to have done.

[Robatron]

Check behind the manifold and see that the vacuum hoses running from the manifold to the dumpvalve and ECU are secured tightly. My Vacuum hose from the dumpvalve had worked loose and the hose to the ECU had blown off completely which basically meant I was allowed one run at full boost and then it never give me full boost again until I turned the car off and tried again.

[UrS4boy]

It may be coil pack kit related, but it sounds more like a boost issue to me. I would verify that all the clamps are tight, and that your new WGFV is hooked up properly. Also, make sure that the coil packs are fully seated down on the plugs - with a "click".

The 1.8T coils can handle power up to and including RS2 levels. I run the Apikol kit, and have for some time, MRC Stage II.

Do an intake pressure test after you check that the coil packs are firmly seated down on the plugs.

Like Silber says, you need to check that the coil packs have been trimmed enough that they fit down onto the spark plugs with a "click". Check out my original DIY instructions from Oct. 2005:

http://www.s-cars.org/postnuke/downl...structions.pdf

Also, in general to track down missing and hesitation issues, you might want to follow this trail:

http://forums.audiworld.com/s4s6/msgs/149788.phtml

Dave F.

[SilberUrS6]

After finally sorting my boost problems last time, with a combination of the following new bits:

New silicon intake pipe to throttle body silicon hose
Intercooler (old one had hole in)
New WGFV
New plugs
New recirc valve
New 034 Motorsport loom and 1.8T coils

It ran perfect for a short while, showing ~12psi on the gauge.
It is now cutting the boost again.

If you warm the car up, and give it full boost, it will show full boost, but doesnt feel "right".
Lift off and try again and it is noticably holding back (feels like fast pulsing on and off boost) but still shows full boost.
Lift off and try again, it then gets to about 5psi and the ecu cuts boost suddenly.
Then everytime of trying after that, it instantly cuts as soon as you try to give it any boost.
If you press the accelerator lightly, you can just about get to 5psi or so, but its still holding back.
It will then continue to cut it instantly, until you park it up, then start again from cold and its the same thing all over again.
So part of me is thinking the heat is killing the coils?

Before I got the 1.8T coils I read varying opinions of some saying they were fine, and others saying they were not up to it.
I am now guessing that they are were, but have already been killed off?

It may be coil pack kit related, but it sounds more like a boost issue to me. I would verify that all the clamps are tight, and that your new WGFV is hooked up properly. Also, make sure that the coil packs are fully seated down on the plugs - with a "click".

The 1.8T coils can handle power up to and including RS2 levels. I run the Apikol kit, and have for some time, MRC Stage II.

Do an intake pressure test after you check that the coil packs are firmly seated down on the plugs.

[S2central.net]

Good point there too !

[UrS4boy]

Test the 1.8t coil pack loom for bad connections, broken wires, etc. This has happened a few times in the USA. Use clip on Multimeter probes and once you establish the proper wires, wiggle the loom to see if the continuity is there or whether it drops.

At least if you build your own 1.8t coil pack loom, you know where to look for problems. When you buy one, its a bit more difficult. It certainly could be something else but don't assume that the loom is fine without checking it thoroughly.

[S2central.net]

NO - coil problems don't show on VAGCOM...

There IS a reason why S2 coilpacks are more expensive than 1.8T ones... But you might just have an air leak, or a bad MAF, or faulty TPS, or dead WGFV


PAul

[dest]

Ive got a laptop and vagcom, just need to get a cable sorted.
If there is a problem with the coils, will that show up on vagcom?