Boost surging?

**Spykce** · 10-11-2008 06:40 PM

I was helping out my cousin who has the exact same car as me. ATW 1.8T Tip trans. However he has a GIAC chip, and forge DV. He was having some issues and we found one of them to be a bad coil pack. However when I switched one of my packs over we went for a ride and found that once he begins to get above stock boost the car surges and shakes.

The best we could come up with before it started to get dark was that he either has a boost leak or a hose is collapsing, like the TIP or TBB. He ordered new coil packs and is planning to take the car to the shop, eurotech in holland, to get the other issue checked. We were just curious on any idea's.

**Seerlah** · 10-11-2008 08:00 PM

Originally Posted by Spykce

However when I switched one of my packs over we went for a ride and found that once he begins to get above stock boost the car surges and shakes.

You just described a misfire. It usually comes on stronger under heavy load. There is no need to take it to a mechanic to pay the diagnosis fee along with whatever else they will charge.

You said he ordered new coil packs, so just wait for them to come in. I would check the car for intermittent codes via VAG com to see what cylinder it is which is misfiring. It is not just the ignition coil which can cause misfires. But VAG com is good because it can tell you which cylinder that is misfiring. After that, you can diagnose the proper cylinder that is misfiring. Make sure he is using the yellow spring in the dv, it is greased up well (even if it is brand new, it is still good to lubricate it as the piston still can get stuck), check hoses and lines, and hopefully you will find the solution in between there.

**Spykce** · 10-11-2008 09:15 PM

Thanks Seerlah, we did get it scannedand it was cylinder 1. Since we switched my coil pack over to his and it was better but not cured something else it wrong besides the pack. However the different pack did make a significant difference. I'll see what he wants to do I'm not sure where to start looking. Guess i'll start searching for info on misfires. Thanks for the info.

**Seerlah** · 10-11-2008 09:21 PM

If it was not the coil, then check the spark plug. It is not always about the gap, though could be the reason. Sometimes the plug is just fouled. Try swapping the plugs from cylinder 1 and 2. I am guessing it is the plug. To give it a good test would be to go WOT in 2nd or 3rd gear

. Then scan again.

**Spykce** · 10-11-2008 09:38 PM

Sweet, Thanks again! When the new packs show up we may just throw in new plugs depending on what he wants to do. A quick search shows that the ATW doesn't have a ICM so hopefully 4 new packs and plugs resolves the issue. Minimum we can try new plugs I just ordered a couple of sets for my car.

**Jibberific** · 10-12-2008 12:37 AM

i had some surging (no shaking or cel though) where the boost would oscillate between 10 and 15 psi, and a new n75 took care of the problem

**Spykce** · 10-12-2008 08:28 AM

If plugs and packs don't resolve the issue we'll be looking for leaks or issues with the boost system I would think. His throttle body boot seemed very soft, however we just drove the car and you know.... everything gets HOT in our cars.

**sageleo** · 10-12-2008 09:34 AM

hopefully I'll have the coilpacks changed by weds, and can take it from there. If its not the coils, would my I be able to buy an n75 locally or is that something I have to order?