R34 Loud Bang, Boost More Than Halved

[surfm8]

I drive a R34 GT-T and have done abit of modification. Upraged fuel pump, bosch 1000cc injectors, link G4 plug and play ecu, greddy intercooler, kiwagana 76mm turbo, spitfire coils and a GFB boost controller, it was tuned at 18psi or so giving it 266rwkw. Tonight i was giving it a few test runs and there was a loud bang and then the boost has gone right back to about 7-8psi. I looked under the hood and noticed a small tubes clamp has blown off and the tube had came off aswell. i have circled where the tube was in the photo below (it was lowest tube on the top section) and air appears to be pissing out from where the tube was attatched. with it being dark i havent been able to look fully into it all. the car still runs and the only problem (so far) is the boost problem. Any ideas on what blew off the car and any ideas on how to fix my problem?

[GTSBoy]

That more than likely is the manifold pressure signal to the fuel pressure regulator. Hook it back up with a clamp and don't drive it until you have. Especially do not try to boost it.

[wolverine]

I don't think that small vacuum hose is going to account for a loud bang.

The hose (we are guessing) you circled obviously needs to be reconnected but I suspect if you have a good look around you will find an intercooler hose has come off.

[ido09s]

Its a bit inconsistant given you heard a loud bang and as said above, you would normally expect a loud bang to be much more than simply a vacuum hose. Unless its the fuel reg hose and it caused the tune to go haywire and it was in a backfire out the exhaust

Obviously reconnect that hose, but i would agree you have probably also popped an intercooler hose. Get underneath and give them a real good look over as they can often look like they are still connected properly after they have popped off.

[surfm8]

Thanks for all your suggestions guys. After getting up this morning I have gone back under the hood and haven't seen anything unusual. Checked connections seeing if anything is loose or leaking but to no avail as of yet. If I can fix this problem is it going to need a retune after the severe boost drop?

[Ben C34]

If you fix it , it is fixed. No retune required. .

[Ben C34]

Also, pressure test your intercooler system. It's the only way to find leaks. search how to do it.

[surfm8]

As normal the masses are right and the main problem was the first pipe from the turbo out to the intercooler had let go. Cheers for all of the input guys, it was very much appreciated! :-)

[C4a0s]

try using T bolt clamps instead of worm drive ones.. those babies will make sure nothing comes loose...

[Ben C34]

If you have shit pipe work without lips or a ridge of some sort to hold the hose on though those won't help much.

[Rolls]

Its a bit inconsistant given you heard a loud bang and as said above, you would normally expect a loud bang to be much more than simply a vacuum hose. Unless its the fuel reg hose and it caused the tune to go haywire and it was in a backfire out the exhaust

My vote is this, fuel reg blown off would make it do something funny, probably also the clamp smashing into the bonnet along with it, might even be an intercooler hose missing.

I've blown my intercooler piping off a few times with the old clamps I had, made a huge bang as the pipe would smack the bonnet and then I'd get a huge cloud of black smoke/backfires, sounded pretty bad when it happened, thought I had put a rod through the block the first time.

try using T bolt clamps instead of worm drive ones.. those babies will make sure nothing comes loose...

as soon as I replaced mine with these I never had a problem again running at 18psi

Edited December 26, 2013 by Rolls

[Ben C34]

I have had a problem using them with a dodgy bit of pipework. I was in a rush and didnt weld a lip onto a piece of pipe and it blew off at 20psi . Those clamps are heaps better, but not going to fix other issues.

[Missileman]

I just replace all my old stock Nissan clamps with these....

http://www.ebay.com.au/itm/150968811647?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Decent quality and not to bad a price.

[C4a0s]

yeah...but if everything else is ok...those clamps are the bomb...

esp with the little lip so it wont cut thru your silicon connectors etc