Boost leak test

[yamiman]

I installed my mcx 270 kit on my nytro myself, I installed the shim myself and all went well ive ran it for 200 miles, but idles rough and of course i didnt check my valve clearances like i should have. My question is I cant build any pressure on my boost guage and I can hear air coming out the back of the engine i believe thru the exhaust. My valves must be obviously toast?

 

[julio]

or your header has come loose or cracked. Not sure on the nytro but on the apex there is a gasket in the exhaust that you can mess up if you force it together, or if you didnt get the pipes right it puts presure on the stock one and they will crack. No exhaust presure no boost.

 

[yamiman]

I just bought the upgrade kit before going on a trip and couldnt get over 12# with it too, i adjusted the waste gate, unhooked the mcx tcv, directly connected the hose from the turbo to the waste gate. Can boost leak through the valves enough to not build pressure, I knew I should have had someone do the install I just wanted to know the ins and outs of it i guess.

 

[julio]

To know if your valves are bad you need to do a compresion test and or a leak down. I would also recomend you do a leak test on the charge system. before you tear it to pieces check those and the exhaust.

 

[Ak nitro]

I think you have a boost leak, if your valves or timing were off I doubt your sled would even be running after 200 miles. If the timming is off by one tooth it would barely run at all. Just plug the intake and shoot 15 psi of air into the hose that goes to the wastegate you will hear where the air is coming from pretty fast. I have done this on both my Impulse Nytro and MCX phazer.

 

[yamiman]

Thanks for the reponses guys ill take a closer look, it just seems wierd I can hear air coming out of the rear of the motor and must have turned that clutch for half an hour trying to seat them darn valves haha, I look for a bigger leak.

 

[TTE]

Do a boost leak test first. Build yourself something like this to do a boost leak test. Remove the airfilter and run 20psi (boost guage) through it and spray soapwater on the charge system.