I had my GSC setup put in today by a very well knowledged mechanic. Anyways, the car runs fine, although sluggish, up to 6k rpms upon which is starts breaking up bad. I turned the boost down thinking it could be blowing out my spark, I am at 13lbs now and it is still doing it. I am NOT tuned. I am on the stock ECU. HOWEVER, my buddy has an 05 EVO with my exact same setup even on the stock ECU and he has no problems at all with his. I am getting tuned tomorrow by Al, but this has to be a problem w/ my car. No one else has this problem when they put their cams in, so I need some suggestions QUICK so I can try to fix the problem before the tune. Any help is appreciated.

BTW, it happens everytime right at 6k rpms.....just like clock work.

 

I would bet the timing is off a tooth or two. IF cams are the only mod you have, no cam gears or anything else, I dont see what else it could be.

 

Also make sure the cam angle sensor wasn't rotated 180 degrees during the install, happens every so often.. Usually if the mechanic isn't familiar with our engine its easy to miss.

 

This was suggested and I will be looking into it tomorrow. According to the mechanic it never skipped a tooth and everything lined up. Guess I will have to check to make sure.

 

Just got off the phone w/ the mechanic and he said everything lined up perfect....nothing was a tooth off. My car idles great, so I would assume it would run a lot more rough if it were a tooth off. I am hoping this cam angle sensor was installed 180deg. the wrong way. The car runs perfectly fine(although sluggish, could be due to me running 13lbs of boost) until 6k rpms and then it breaks up right then everytime.

 

Cam sensor with engine at TDC should have the small vane at 10 to 11 o'clock position.

TDC on camshaft at #1 cylinder would have the intake lobes pointing at intake and the exhaust lobes pointing at the exhaust manifold.

Also to check cam timing line up mark on damper and pop the cover off of the timing gears. (4 bolts) Obviously if they are 180 out you need to turn it over 1 more crank revolution. The marks should be very close to the marks on the cam cover. 1 tooth off is usually wasy to notice because you can see the tooth in between where it is and the mark. Always rotate the engine clockwise.

 

Check all timing on cam gears when crank was aligned....everything was spot on. More news, I got a cel, so hopefully tomorrow I will be able to scan it and see whats pissing off my my car. Checked the plugs, I swear the look lean as crap. Don't know how since I am running a walbro on a stock ECU, but I think this may be a tuning issue. Another thing, I can rev in neutral all the way to 7k w/ no problems, but if there is any load on the car at all(I just casually accelarate up to 6k while mostly remaining in vac or barely boosting at all) it will break up again. Hopefully this cel will give me an idea tomorrow morning.

 

just a thought. make sure your balance shafts are in phase. the one that is on the oil pump. if it is out of phase you will get a lot of vibration and it might be bad enough at 6k that the knock sensor thinks it is knock and pulls a lot of timing and fuel. i cannot look at your car to see exactly what you are experiencing but there is a bolt on the back of the block which is i believe a 14mm and if you can put a phillips screwdriver through the hole once you take the bolt out and all the timing marks are all lined up you are good, if not, your belts will need to come back off, and the oil pump sprocket will need to be turned a complete turn. good luck and let us know what you find.

 

Why does the oil pump have to be in time also? Aren't the cams perfectly round in the journals? I don't quite understand why the oil pump has to be in time...

 

I realize the problem showed up after the cam install, but check for boost leaks. It's possible he removed some hoses to do the work and didn't tighten something back up, or just leaned on something and pulled it loose.

 

Oil pump is connected to the front balance shaft. They have to be in time so the oil pump does too.

 

1.8T is my brother. They figured out the problem. A rocker arm was knocked slightly loose during the intake cam installation and it resultantly ended up falling completely off. Luckily it didn't get caught up in anything and no damage occured. The car was breaking up badly because that cylinder was basically being washed down with fuel since only 1 intake valve was being actuated.

Either way, the car is now fixed and is waiting in line at this very moment to complete the custom dynoflash

 

Still waiting but there was a TINY bit of damage. The lifter got nicked when the rocker was knocked off. Still seems to hold pressure though. Everything seems fine.

 

good to hear all is well. If you get any numbers please post.

 

Glad to hear everything came out alright. I think a light breeze would know the rockers off.