my 1994 integra vtir has lost boost at 5000 and beond, with the low rpm cams it drives fine when trying to accerelare past 5000 it does not boost like before then as it gets higher it looses acceleration and sounds as if engine is strugling........
vtec problems?
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Your engine WAS cammed for natural aspiration. NOT turbo. Therefore the overlap that was in place to get better N/A performace is ruining your boost as its dumping it down the exhaust, probably causing a lot of problems with AFR mix as well.
Get adjustable cam gears or get some cams made for a turbo setup not a N/A one and you'll be fine.
I saw some guy post about this a long time ago with his turbocharged lotus. I learned about this problem after reading through a K series forced induction build.
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LOL ok, you said boost. anywhoo.
Vtec may not be working, do you have a check engine light on?(CEL) have you recently Over-revved your car? Have you noticed it smoking? Done regular maintainence such as air filter, and using corect fuel for your car. Not putting in aviation fuel? Checked your distributor, rotor, spark plug wires, spark plugs? Fuel system ok? Changed the fuel filter as scheduled? Though rare , injectors could be gummed up.
Thats just some of the problems you could be facing.
EDIT: Oil pressure certianly plays a role in VTEC's activation. Make sure you have adequate oil in your car... I've seen somoen ask for help and that was their problem lol.
The solenoid could be stuck, they do that form time to time. You can manually trigger it with some voltage applied to it. If you know how to use a Volt/Ohm meter you should be able to troubleshoot it easily.
Vtec may not be working, do you have a check engine light on?(CEL) have you recently Over-revved your car? Have you noticed it smoking? Done regular maintainence such as air filter, and using corect fuel for your car. Not putting in aviation fuel? Checked your distributor, rotor, spark plug wires, spark plugs? Fuel system ok? Changed the fuel filter as scheduled? Though rare , injectors could be gummed up.
Thats just some of the problems you could be facing.
EDIT: Oil pressure certianly plays a role in VTEC's activation. Make sure you have adequate oil in your car... I've seen somoen ask for help and that was their problem lol.
The solenoid could be stuck, they do that form time to time. You can manually trigger it with some voltage applied to it. If you know how to use a Volt/Ohm meter you should be able to troubleshoot it easily.
yeah sorry i ment the like vtec powerband i guess it might be called ha ha. when it first happened i was in 3rd at 7and a half thousand so not quite redline then it just sorta went clunk then started to slow. not smoking at all, i run shell vpower in it. thanks for the help when service i am changing the lot so ill see what happens fom that.
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What do you mean it went clunk.
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shell v-power FTL
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Compression check it! If it passes, Leakdown test it, then you'll know what its not.
EDIT: lol remove oil pan and collect piston rings off of girdle.
EDIT: lol remove oil pan and collect piston rings off of girdle.
well clunk was the best sound i could for the action. it just stopped accelerating i guess is the best way to explain it. nah no clunks or any problems untill high revs there is just no power and it stops wanting to accelerate and is fine when back at lower revs??
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Get a test lite, hook it up to the vtec solenoids wires, drive car and run it into where vtec should engage, note if light comes on. if it doesn't ECU isn't sending voltage to solenoid, if it does come on suspect faulty solenoid.
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