Boosting too soon

[andrew4g63]

I just bought a 91 AWD Automatic Stock. Not always but most of the time when i drive i get boost at about 1300-1500 rpms no matter how far i have the throttle. Then it will not rev over 3500-4000. I changed the fuel filter,pcv, and changed the wastegate to a known working one. Ideas would be helpful.

 

[GSX93DSM]

I Know On A Lot Of The At Cars They Come With 13b Turbos That Might Have Something To Do With The Boost But Im Not Sure About The Rpm Deal. You Don't Have A Boost Leak Anywhere Do You?

 

[JDNSBR]

I just bought a 91 AWD Automatic Stock. Not always but most of the time when i drive i get boost at about 1300-1500 rpms no matter how far i have the throttle. Then it will not rev over 3500-4000. I changed the fuel filter,pcv, and changed the wastegate to a known working one. Ideas would be helpful.

When you say you get boost at 1300 or 1500 rpms you just mean a few lbs right? On a small turbo like the 13b that is pretty normal. As for not being able to go over 3500-4000 rpms I would check your spark plugs or wires. I would check those.

 

[andrew4g63]

No it is full boost. I have brand new plugs and wires. Could it be a stuck wastegate. Also when it does go to high rpms there is no power and tons of smoke coming out the exhaust.

 

[xcelr8n]

The stock gauge is reading this full boost at 1300rpms?

 

[blackGSX2g]

No it is full boost. I have brand new plugs and wires. Could it be a stuck wastegate. Also when it does go to high rpms there is no power and tons of smoke coming out the exhaust.

Is this verified with the stock boost gauge or an aftermarket unit?

If your wastegate was stuck open, you would take forever to build boost. If your wastegate was stuck closed, your spoolup should remain the same but you would over boost on high throttle situations.

What color is the smoke?

 

[andrew4g63]

yes full at 1300 and the bov is super loud when i let off the gas

 

[Livid]

Not going over 3500-4000 rpm.. Could be a fuel issue. Check your fuel pressure and make sure you aren't leaning out when it hits boost.

 

[andrew4g63]

stock gauge
not a wastegate problem then because it stays spooled at 14psi on stock gauge and let off gas and does not go down on vacuum
smoke is grey andsometimes black-blown turbo?

 

[cyclonetsifwd]

get an aftermarket boost gauge. 14 is as high as the stock gauge goes on the 1g's. for all you know it could be higher. they are very inaccurate anyway.

 

[andrew4g63]

yes i know they are inaccurate but im broke so im stuck with it for the moment

 

[PieEyedPiper]

oo! I've got it!!!
His needle is off on his tach! He actually boosts at 2800 and bounces off the rev limiter at around 8k!!
ok, so maybe thats not your problem, but I couldnt resist after reading your thread.

good luck!