alright i just bought the tpi off of zepher,now,he came up and hooked most of it up,i finished it up,at least i thought i did,there is a leak somewhere,its an airleak,cant tell where its coming from,except from the tpi somewhere,my dads thinks vacum,so we took off the plenum and checked where all the vacumes would be,they obvious ones werent it,is there any,that you guys missed in the pass?its a very big leak to,hear it over the engine.also what is the thing ontop the intake base,and it has a wire coming from it,where another wire would plug into it,i have a 87 tpi converted to sd,is this just not used?i have a 77 engine,so we had to grind out the center bolt holes to make it work,could this be my leak now?this is the only thing left holding me up from driving her for the first time since the swap,other than the master cylinder,but i need to do somethin bout this first.any help is greatly appreciated. thanks.

 

If the leak is big enough to hear over the engine it should be easy to find. The center thinga-ma-jig is the EGR. Usually blanked off in SD units. It is probably blocked open with no lines connected to it. You mentioned the master cylinder. Is it installed with the vacuum line connected? Also check to see if the PCV valve is bad.

 

Anywhere you think it's leaking spray carb cleaner around the spot, if the idle picks up you found it.

 

use a piece of hose. Hold it to your ear and the other end down by the motor. You can here alot better and should be able to locate the leak.

You can also put a piece of hose onto the end of a propane torch.
Just dont light it. turn it on and cap it off with your thumb. when you want to check a place release it. If the idle pics up you have found it.

The same as dano 00ta said with the carb cleaner.

good luck.

 

alright guys i actually took out the egr thing,welded the hole shut,my friend thought it might have been that,but it wasnt,there leak seems to disapear when ever you would put throttle to it,my other neighbor said that it sounded to him like it was coming from the drivers side plenum/runner area.the gaskets are brand new,i didnt get to try the carb cleaner today,but i will try it tom.what are the chances of our modded intake holes leaking?the engine has 10.1 compression ration pistons,could it just seem like a leak,and really just be sucking that much air?i plugged up the pvc valve,and the brake booster line is on the back of the intake,the little vacums up front are all blocked off,and the 2 on the passenger side back are both connected with the map sensor's,and what ever that other thing is,is there any that im missing?i didnt think it was just sucking that much air,cuz i can put my hand over the tb,and pretty much close it,and its still there,not as bad though,what do i do with that fitting on the front drivers side?that isnt it either,i just noticed it,all your help is greatly appreciated,thanks.

sorry so long of a post.

 

Does your set up have a cold start valve (9th injector)? If so check it for an O ring where it plugs into the driver's side runners/manifold. Even if it is there you may have it cocked in the hole and letting air in around it.

~M~

 

Check your timing! If the timing on a TPI car is too retarded, it will make a loud, sucking sound. Trust me. Also have you felt the brake pedal? Did you hook the booster line to the port in back of the plenum?

 

THIS IS LONG, BUT MAYBE HELPFUL.

STEP 1) Sure fire way to check if you actually have a vacuum leak. Remove the inlet elbow or filter so you can get to the throttle body inlet. Take a piece of cardboard or a heavy plastic bag. Put either against the front of the throttle body. if the engine starts coughing or dies, you have no leaks.
STEP 2) If engine dies, check adjustments of throttle plate, idle air control motor and throttle position sensor.
STEP 3) If engine continues running (YOU HAVE A LEAK). There is a threaded hole under rear of plenum for the MAT (manifold air temperature) sensor. Make sure it's there. There is a bolt about 2 inches long on each side of runners that screws in from the opposite side of engine, easy to miss, make sure they are there.
STEP 4) Maybe the key. You said you installed TPI on a 77 engine. Did you use the short rubber pieces of the intake gasket set. If so, that is your problem. You must use special silicone sealant on the front and rear of the TPI intake. The rubber pieces are too thick and will not allow the side gaskets to seal properly.

 

Just tried to reply to your message. If you did not get it mail me at wayne@metropower.com