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DDDD DDDD is offline
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Join Date: Jan 2007
Posts: 1,077
Quote:
Originally posted by h20cooled7
OK ,BUT I STILL DIDNT GET THE ANSWER FOR THE MANUAL BOOST KNOB , CAN I SHUT THIS VALVE AND HAVE THE CAR RUN LIKE IT WAS STOCK WITHOUT AFFECTING THE MIXTURE


As far as your question about turning back the boost, this is only a guess, but if the CIS had been tuned by the previous owner to run at like 1 bar, or even more, and you cut the boost back lower than that, you may be running rich. Hence, you simply have to pick your boost level first, and tune accordingly.....I think that if you shut your boost valve off, you should get boost according to the actual boost spring in your wastegate, which I am just guessing would have been upgraded to 1 bar, considering how much boost you have been running. But maybe it is the ole' .8 bar spring.....

But what you are saying, I think, is that you are running more than 1 bar boost. If that popping sound is from too lean a condition due to insufficient fuel under too much boost, you are seriously in danger of killing your engine the next time you drive hard and it is a hot day. As in piston melting and major rebuild and over $10,000 down the drain. There is a chance that you heard detonation, I am not sure.

Tuning your boost knob to a specific boost level, like 1 bar, and then tuning your air fuel ratio to 1 bar is the first step. I think you should consider bypassing the boost knob completely and just put a 1 bar spring in your wastegate. That is essentially what I did, I had a knob of death like you, and my boost was supposedly set at 1.1 bar but would just go all over the place, and I now run a 1 bar spring and get dead accurate boost every time in every gear, so I can tune my AFR precisely.

This is something you need to do whether or not it has anything to do with your current problem. Maybe it is related to your problem, maybe not, but it is the required first step in not melting your engine.

As somebody already said, you might have distributor problems. If one of your plugs isn't firing right, than that is bad news. I would upgrade to a newer CDI type unit for precise timing and a stronger spark, if the distributor is starting to seize up.

If you are running so much boost that you are hitting the overboost cut off, you are in serious danger of melting your pistons. But I find it hard to believe that somebody put a knob of death on your car without disengaging the overboost cut off switch, because usually that is part of the 'procedure' in hot rodding your turbo. That is something you can check, but the fact is that you have no reason to run so much boost as to hit the kill switch in the first place. You really should stay at 1 bar of boost.

All I know is that my system never stayed at one boost level until I bypassed my boost knob, and then my AFR could be set more accurately.
Old 05-10-2007, 06:02 PM
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