Boost Issue?

[satty]

I am new to owning a skyline. Dont know much.

The boost in my car is set to 0.6 only in second gear at like 3000revs the car splatters and loses power. Soon as it in third the gear changes become smooth.

Really confused.

[SECURITY]

its probably your coil packs. its a common problem in the r33's.

take them out and get the coil packs cleaned on the inside with some steel wool till theyre all nice and shiney on the inside.

its either that or your spark plug gap is too big (although 1.1mm should be fine on standard boost).

[Zoix]

jsut wondering what happens if they are too close or too far apart? I think the 5000rpm stutter is the coil packs, I've got too do mine this weekend, was going to check the spark plugs also.

[SECURITY]

if theyre too far apart on higher boost the spark may get blown out by the force of the air entering the combustion chamber.

if the gap is smaller, the spark will have more of a chance of detonating the air/fuel at the right time as the spark has a smaller distance to travel.

a con of having a smaller gap is the spark wont be as powerful as a spark gapped at 1.1mm. this is why people buy splitfire coil packs and make their gap larger than the .8 that is recommended with standard coil packs.

hope that makes sence

[khunjeng]

yeah I concurr with everything that was just said! buy some XIs from Kudos motoesport in the trader section for 99 delivered...and also have a look at the coild backs for the hairline fracture...get some spitfires if u have the money...overwise do a dodge fix and u wil be set for a while...also while ur at it check ur leads...or just replace them...then u know everything is cool..

[SECURITY]

nah they dont need replacing, plus it isnt a dodgy fix if you're cleaning the inside of the coil packs with a dremil or steel wool.

over time they get a build up of crap inside them. this stops the route to the spark plug from being the shortest path to earth (which is how electricity behaves) as the build-up of crap is stopping the coils conduct with the spring properly under load. just clean out the shit inside it and you'll notice a huge difference. make sure you do it carefully though.

i did mine at around the beginning of last year and they were good till last december when i took my car off the road for blowing #6. and im sure they'll be fine for another few years. i even took the tape off when i did it and they worked just as well.. no missfire for a year.

heres what they look like before (not my coil packs):

and these are my coil packs after cleaning them:

[satty]

its probably your coil packs. its a common problem in the r33's.

take them out and get the coil packs cleaned on the inside with some steel wool till theyre all nice and shiney on the inside.

its either that or your spark plug gap is too big (although 1.1mm should be fine on standard boost).

thank you for advice

[JimX]

Time for a bit more info on this thing I didn't write a post up about it yet because the car needs to be repaired first (the accident or should I say incident was not her fault in the slightest, long story which I won't go into here). Anyway here's the basic rundown and why I don't think it's the coils.

Firstly, the old coils were good up until about 1 bar of boost, then it would get the misfiring problem at anything higher which I discovered when I had it tuned last year. So I got Splitfire coils which fixed it. Before selling the car I decided to put it back to stock(ish), but tested the old coils at 1 bar first, to make sure that they were still ok. Everything was fine.

So then I put the rest of the stuff I was selling back to stock. Injectors, ECU, AFM. Then I noticed that it was getting the misfire problem again, at about 5000rpm as seems to be the norm. Luckily I still had the Splitfires so I threw them back in to see if that helped, and it didn't make even a slight difference. So I was and still am 99% sure that it's not the coils.

Next thing to test was the AFM. I couldn't put the Q45 AFM and PowerFC back in because they had been sent to their new owners already, but luckily Andrew from Kudos Motorsports sent me a stock replacement express post (thanks Andrew!), and this seemed to make a difference. Instead of misfiring ALL the time, it was now doing it maybe half the time and seemed to be improving. I then decided it was the factory AFM making it run too rich and fouling the plugs, but now with the new AFM it was running correctly and blasting off the carbon.

At this point I decide to put the car on the market, but Emma gets a new job and says she can afford to buy it, so she is driving it around herself for a couple of weeks before she has the incident mentioned above. During that time though we discovered that the misfiring problem was gradually returning. I found that I could lessen the effect by winding the boost down, but gradually it started happening at lower and lower boost. Even though the EBC was set to 0.6, I think that the adjustable wastegate actuator is set to around 0.8 so I don't think we've managed to drop it any lower than that. I would need to road test it to check but obviously that's not possible yet.

Other things I've tried were changing the plugs to new ones, it didn't make any difference and the old ones weren't fouled anyway so now I have a spare set. My current theory is that it's factory boost cut, but I unfortunately don't have a PowerFC anymore to test this theory. The turbo is not stock, it's a 450hp Garrett so this would generate extra problems for the factory ECU. The fact that the misfiring issue is moving around depending mostly on the changing of air flow (boost) or measuring it (AFM) makes me think that the ECU is "learning" how to cut the boost again whenever I change something, similar to how it learns how to idle, and back off timing when it detects detonation. A simple test will be to reset the ECU once it's on the road and see if it improves anything.

I think that's the whole story! I was going to post all this up after the car was back on the road, but Emma's very eager to learn and she thought she'd put the post up about it