Hey guys, At the end of my drive home, there is a monster hill, more like a small mountain. Anyway, I drive up and down the hill everyday with no problem. Upon reaching the top today I felt an odd vibration in the car. When I pulled into my driveway, the car was running pretty choppy and holding a lower than normal Idle. The car does not stall and seems to rev fine. This is very odd for my car because she always purrs. The strange thing is that I was looking for a loose vac line or harness clip and while blipping the throttle, I noticed the ports opening and closing?? I've never actually seen them do that, they shouldn't be doing that with no load. I'm going to let it sit until tomorrow but has anyone ever experienced this?

 

I've witnessed it. I am guessing that you are still using the stock split air pipe backpressure to feed the actuators. What kind of mufflers are you using? Restrictive mufflers will cause enough back pressure to do this.

(as will recent cleaning and polishing of the actuator rods and bearings, as well as the auxilary sleeves, and lowering the opening pressure on the auxilary ports as low as they will go.)

 

I am using the racing beat header and pre-silencer setup with a stock TII cat back. Ive had this setup for a couple of years and I have never witnessed this. It's nice to see them actually working but it's coming in conjunction with a mysterious rough idle. And I havent cleaned anything recently either. What would cause increased load on an idling motor?

 

bump

 

alternator pully or water pump pully not being lubed

 

hmm, now thats interesting? Ijust recently put on a dual pulley, It seems a little noisy. That might be it, gotta check that. thanks

 

You don't lubricate pulleys... that's retarded. If you have belt squeel, you adjust your belt tension.

The prupose of lubricating is to lower the friction between two contact surfaces. If you did this, your belt would slip, and you would lose waterpump rotaional speed and alternator rotational speed, under all operating conditions, undercharging the vheicle and undercooling it.


Worst advice ever. If you don't know, don't post.

 

Adding a dual alternator pulley will NOT increas engine load by any significant amount. The ONLY reason to add a dual alternator pulley is when your belts start to slip, and its only purpose is to double the belt contact forces for increased friction (essentially, it doubles the normal force). This minor increase in friction will not cost any power whatsoever on any dyno, so its intrusive load onto the engine will not be any sapplicable amount higher.

Increased engine load from the pulley system can only come from: failed bearings/shafts in the water pump and alternator, causing binding and a much-increased frictional loss. It would also give excess noise. If you have noise, investigate how freely the waterpump/alternator turns, and forget about the belts.

Shortened: dual alt pulley will not increase engine loads.

 

hmm, well was willing to listen to any idea, I've conquered hundreds of problems with my FC but I have never encountered this. Nothing on my car changed physically. I didn't change the exhaust in any way. I can not see any logical reason why the ports would be opening. Unless maybe a portion of the inside of the muffler collapsed ?

 

so, no other ideas? anyone?

 

The ports shouldn't be opening with no load on the engine... that right there means that there's a pretty severe restriction on the exhaust system.

Normally, this would point to clogged cats, but you don't have any. It might be worth pulling off the mufflers & seeing if the engine frees up - clogged/collapsed mufflers sounds like the only thing in the exhaust system that could be producing that kind of backpressure. Or just pull the exhaust system open at any joint you can get at. If the problem goes away, then it's the mufflers. Before you spend too much time looking at engine related causes, check the exhaust system.

-=Russ=-

 

ok, update: I drove the car to work today after a very difficult startup. It took me about ten minutes of cranking to get it to turn over but finally it did. I decided to take it easy on my trip to work because I had still not solved the problem. There is one part of the parkway I travel which has about a 30% grade incline. As I tried to accelerate up this hill, the car bucked violently and started to stall. I was fortunate enough to keep it running and get it off of the highway. I pulled over and checked everything out while the car was still running, I saw nothing apparent. I was then able to granny the car down to work. I ran my thoughts past the company mechanic and he pin pointed a problem, I had a few spots that were arching on my plug wires. I wrapped the wires in loom to stop the grounding out but the problem was still there. We then pulled the plugs and found the real problem. A broken center electrode on one of my plugs! I'm not sure which rotor it came from because he pulled it. I put in new plugs and new wires (stock ones UUgh, no more 10mm) and the car seems to be almost all better. I still have a slight rumble during my acceleration and the ports still open on their own when I open up the throttle. I'm going to take it home 45mins and see how she is on the highway. Any comments would be appreciated.