So I was driving around tonight trying to figure out whats going on with the car. I noticed that when I accelerate hard, In first gear The boost hits around 10 PSI at 2000 RPM, then it bounces back and forward a couple times from 9 to 12PSI give or take, then at 5000 RPMs it hits 15,16000 PSI and stays.
Its like the car builds up to 10, then cant grip and then at 5000 hits 15 psi. I can really feel a huge power change at 5000 Rpm. this happens in ever gear (the power difference at 5000 RPM, not the bouncing from 9-12 psi, I couldnt get that fast with the speed limit etc)

thanks for the input!

 

Sounds like it could be the belt. How many holes are showing on the tensioner?

 

not sure. I'll have to check again. It was only an hour ago so it was dark out. I'll have to have a gander tomorrow around lunch.
I hope its an easy fix... because if i can have the power i get at 5000 down low, I'll be very happy.

 

Well, changing the belt would take all of 8 minutes. You still have the belt tool, right? That is, if you installed the pulley yourself. Either way, it would be a good tool to have if you're going to keep the car awhile.

 

No I'll have to buy one. I didn't install the pulley. Any advise on a good belt? given that could be the problem?
thanks

 

With your 15% s/c and 2% crank? I have no idea. Sorry.

Maybe someone with both pulleys can tell us what they used.

But, assuming that the car used to run perfectly with those pulleys, just get the same belt that is on it now. How many miles has it been on this belt?

 

I took the 2% off. so i only have the 15% on now

 

the belt has been on the caar for around 32000 miles

 

Had the same kind of problem, it ended up not even reaching 13 lbs. replaced belt (stock, with 15% + -2%): nothing . Replaced blow of valve: 15 lbs right now!
The old B.O.V would stick open or half way , until after a few weeks, the car would go on limp mode. Just saying' it might not be the belt.

 

hmm so it may be the bypass valve? interesting...
Or do you have a blow-off valve???

 

could I be experience the "yo-yo effect" Ive herd of this before...

I just ordered the Detroit Tuned bypass valve. maybe this will help.

 

I use a Napa xxx535 with a 16% on advice of Jan, and almost anyone. No slipping. But, I also left the stock belt on with the 16% for like 15,000 miles with no slipping either so...

 

Sorry! bypass valve .

 

yeah So far i havent had issues with belt slippage so i dont know why it would start now. I'm going to see what this new bypas valve does for me, then I'll see about the belt...
I think i'm getting the yo-yo effect....thats just an assumption on my part though.

 

Hi - any update? Did the bypass valve make a difference?

I just got a Jan tune and there was some yo-yo in the boost values at high RPM. My belt and tensioner are less than a year old. I wonder if I should replace my bypass valve...

 

Zip tie it shut, drive it, if it makes a difference, you should then check for vacuum leaks, (it works on vacuum you know) if there's nothing apparent, then yes, change or rebuild it.

 

Is your purported slippage accompanied by a foul odor of burning rubber frm the belt ? Typically the case.

If you have a 15% pulley, the NAPA 060535 or equivilent is the recommended one.

If you have a 17% pulley, the NAPA 060532 or equivilent would be the best one.

 

Has anyone ever used "belt dressing"?

 

I am using 17% pulley and the 060532 belt. I've never noticed any belt smell our signs of rubber dust. I have the right belt and the tensioner assembly is new, and I'm pretty sure I have no vacuum leaks. I guess the bypass valve might be suspect.