Thread: Going WOT but boost is NOT.

What I have noticed about my car lately is when I go WOT, my stock boost gauge would only go about half way. A few months ago the boost at WOT would go all the way but one bar, now it seems it is worse. And my car seems to have no power at top end at all. Once it shifts into 4th, it will stay at 4k RPMs and not go any further. It is weird. I am just curious on what might be causing this, What should I take a look at? I tried looking up this problem and really couldn't find what I was experiencing.

vacuum leak maybe?

My belt is squeling, a little bit, not too loud. New belt or belt dressing? Or I think I heard just water will help?

I've checked four times for vacuum leaks. Couldnt find anything.

check your belt before you by a new one, take it off flip it groves out, and bend it, if there are cracks and chunks missing, get a new one, if its real dirty and no cracks clean it with warm water, dish detergent and a scrub brush, dry it and re install it.

while the belts are off, take them both off and check them, turn all of your pulleys make sure they spin free and have no excessive play in them.

and belt dressing is crap, dont bother it last like an hour and the squeal is back.

Try a wet bar of soap instead of belt dressing.

Lasts longer.

A lot.

Ok, well there seems to be some cracks and a few chunks missing from the belt. Would it be safe to drive without the belt to go buy a new one?

Safe to drive.

Thanks. But I am not really sure this will fix my problem. Seems a little to easy lol.

Check the spark plugs, condition of the plug wires, coil terminals for corrosion, rubber "T" fittings and plastic vacuum lines around the fuel rail/supercharger/lower intake manifold/MAP sensor in the back...sounds like since it drives fine but once you get into boost the vac line splits back open.

Easy way to test is...

When the motor is cold, start it...and spray carb cleaner around all that crap...if the idle changes, you have found a vac leak.

I can check again for vac leaks. I took a look at my pulleys while the belt is still off, they all spin freely beside my SC pulley. It will rotate when I spin it, just not freely.

Originally Posted by fri3dchick3n

Thanks. But I am not really sure this will fix my problem. Seems a little to easy lol.

if your belt is torn up, its old, and they tend to stretch/wear the V groves off, then it slips. if all your pulleys seem ok the new belt should stop the squeal and fix the boost.

some part stores have a gauge you can put in the groves to see the wear.

Originally Posted by Rico

HaHa. Yea, you would have a serious problem if that SC pulley spun "freely". Don't forget, it's a roots blower and it's moving a lot air.

Yea, I just wasnt 100% sure about it so I thought Id still mention that part. Well I am very happy to say that with the new belt replaced, I get FULL boost at WOT now. Yay. Still noticed it had a hard time in 4th gear after 4k RPM. I will check what blue mentioned now, hopefully figure this out. Though I have checked for vac leaks many times with no luck of finding a leak = \

I think the fuel pump was replaced a few years ago by a mechanic trying to figure out why my car was dying randomly on the road. Ended up being the Fuel Pump Resistor though. Fuel pressure it good too.