Boost Leak Test

[dank GN]

I just did a boost leak test and found some leaks. there is a pretty substantial leak right by my TPS and on the other side where my linkage is. Is there any O rings in the throttle body that need to be replaced?? does anyone have any pictures of a TB torn apart?? i also have a fuel pressure problem . My fuel pressure bounces when i get into boost i think that this may be the cause?? Any help would be appreciated

Thanks,
Dank Gn

 

[Audie1]

I just did a boost leak test and found some leaks. there is a pretty substantial leak right by my TPS and on the other side where my linkage is. Is there any O rings in the throttle body that need to be replaced?? does anyone have any pictures of a TB torn apart?? i also have a fuel pressure problem . My fuel pressure bounces when i get into boost i think that this may be the cause?? Any help would be appreciated

Thanks,
Dank Gn

Yes there is O-Rings on both sides of the throttle blade. I looked for a breakdown on my CD Rom Shop Manual for the Throttle Body but could not find it. Sorry I could not be of more help. :redface:

 

[dank GN]

I ended up pulling it off right now i have some new ones on order from g body parts. i put some o rings behind the teflon seal it helped a little bit .

 

[TurboMonte 2]

Be very careful of the swinging FP when you get into boost. Insufficient fuel supply on-demand is NOT a good thing... You need fix this prontito!

It's unlikely the boost leak around thr bdy has anything to do with this more-severe problem...

 

[dank GN]

I have replaced the whole fuel system ( Pump,Injecter,Reg,Filter) i just cant seem to find why my pressure is bouncing.i would set my FP to 42 line off then i would put the line on and it would only drop a psi. Now that i put some o rings in where its leaking at the TB it drop 4 psi i think this may have something to do with my bounce. I will let you guys know when i get the teflon rings in if it fix my FP problem. Any ideas of what this bounce could be i am all open ears????

 

[TR Custom Parts]

I have replaced the whole fuel system ( Pump,Injecter,Reg,Filter) i just cant seem to find why my pressure is bouncing.i would set my FP to 42 line off then i would put the line on and it would only drop a psi. Now that i put some o rings in where its leaking at the TB it drop 4 psi i think this may have something to do with my bounce. I will let you guys know when i get the teflon rings in if it fix my FP problem. Any ideas of what this bounce could be i am all open ears????

Are you having boost surge at the same time as the fuel pressure bouncing??? If I remember right, when I had boost surge the fuel pressure gauge would be bouncing like crazy. This was when I was running my TA49.

 

[dank GN]

i have a stock turbo it does surge alittle . It still bounces when its not surging?

 

[TurboMonte 2]

When you connect vac line to top of FPR it should drop FP by 5-6 psi--if your engine is pulling decent vacuum AND this vac line is not leaking (like stock/original ones will crack/break at one end or other of more-rigid plastic portion)...

Turbo surge is not typical with a stock turbo--what max boost are you running?

 

[dank GN]

20lbs. of boost. My vac leak at my tb is pretty bad i am hopin that when i get the new seals in it will cure this fp problem

 

[TurboMonte 2]

The same leak at idle vac will be 2x as bad at 20# boost.

At 20# boost are you seeing 62# FPres--or what??

 

[dank GN]

It does get up to around 59ish but it is bouncing all over the place

 

[TurboMonte 2]

How does FP bounce compare to boost bounce (if any around 20 psi boost max)-- (apprx. psi ranges)?

 

[dank GN]

There is alot more bounce in the fp there is barely any in the boost it has to be that boost leak

 

[blacksix]

FP gauge good?

 

[Razor]

I had a local car recently with a clogged return. The hangar inside the tank had gotten clogged on the return. So FP would only drop a little when the hose was hooked up.

The return is the hangar tube that holds the fuel pump.

 

[dank GN]

I put alittle compressed air through the return line it sounded clear

 

[corsair231]

What may be causing the problem is a boost induced leak. It could be closed at vacuum and as the pressure builds it may be opening up. Check all of your vacuum lines for hidden cracks and dry rottted or soft hoses. Zip tie or clamp your connections too. Also 20 pounds is pretty stout boost on a stock turbo. Your surge may be a result of your fuel problem or the cause of it. Your stock turbo, especially if it is well worn, may be falling off of the back end of the map and having flutter instead of surge. This can be causing changes in the signal to the regulator and making the fp pressure change. Check your vacuum lines and if that doesn't fix the problem then back off of your boost a couple of pounds and see if it goes away.

If neither helps the problem and the pressure continues to bounce at idle then you may have a mechanical problem. A leaky intake or head gasket or if it is a quick bounce then it may be a valve train problem.

 

[dank GN]

thanks i will check out every thing out. when i did my boost leak test i found that my lines where leaking at the TB. i zip tied all of them the only spot where it leaks is those seals so i have them on order i will let you guys know if it fixs the problem. I sure hope its not mechanical