toplessFC3Sman

iTrader: (1)

Ok, I have an 88 TII engine that I just got wired and mostly plumbed into my 88 vert. I just got it started earlier today (for the first time, WOOT!), and noticed that when the MAF is propped open (just a fraction of an inch) I hear a solenoid valve click, and then a hissing noise starts coming from somewhere around the rear of the engine. This happens even when the engine isnt running, so I dont think it could be a vacuum issue. What is it? Injector stuck open? (altho i dont know why a solenoid would click for this)

Just some stuff on the engine, I dont know too much about it, compression seems good on all faces, air pump and all emissions removed and blocked off. The MAF isnt hooked up to the intake yet, and the exhaust isnt attached either. It didnt come with a BOV, and I have yet to buy one (so for the moment it's just plugged, and since I'm just starting the engine and essentially letting it idle, i'm not worried about boost spikes). Besides these, everything seems to be complete.

classicauto

iTrader: (3)

You running a BAC?

toplessFC3Sman

iTrader: (1)

nope, that was removed/blocked off by the engine's PO

classicauto

iTrader: (3)

In that case Im out of ideas

I can't think of anything that would actually be SUCKING when the engine is not running. I can garuntee you its not the AFM though since its really just a tube with a flap....nothing that would make any type of noise like you describe without being hooked up to a running engine.

Are you sure its not the fuel pump coming on?

HAILERS

Opening the AFM vane makes the fuel pump run if the key is to ON. Your hearing the fuel pass thru the fuel rail on its way back to the fuel tank.

toplessFC3Sman

iTrader: (1)

hmm... that makes sense. It was kinda loud and noticable, im going to recheck for possible leaks, just in case. Id rather not be the proud new owner of a melting fireball

HAILERS

There is a SWITCH in the AFM that is actuated with the movement of the vane inside it. It only takes a very small movement from full close to just barely open to acutate it.

There is a two socket, yellow in color elet plug near the right strut tower called the Fuel pump check connetor. To pressurize the fuel system without running the engine, you put a jumper b/t the two sockets on that connector.'

By accomplishing that, you do the equivalant of moving the AFM's vane aft a touch. The fuel pump should run when you do either of the above AND the key is to ON.

Also, what the fellow said in an above post about the BAC is very true. Turn the key to ON, and you SHOULD hear the vibration of the BAC's piston moving back and forth at approx 120hz. Engine does not have to be running for this to happen, just the key to ON.

To see if the vane in the afm is the culprit, just remove the airfilter and make sure the vane is all the way fwd. IF the key is to ON and there is no jumper in the Fuel pump check connector, then there should be no fuel flowing thru the rail making a *sound*. Hissing sound to me.

toplessFC3Sman

iTrader: (1)

ok, that sounds like its exactly it. It was a nice hissing sound that I never noticed on the NA engine... but then again i didnt play withthe AFM too much. The BAC isnt there, so that cant be the culprit, sounds like its the fuel pump then. I havent figured out how to swap in the fuel pump resistor relay yet, but I'm not sure if its necessary unless I use a TII ecu instead of the N338 already in the 88 'vert