Thread: Once more into the breach!

Sorry guys, its a 1994 Disco 1 with a 3.9 v8, i think they call it the Hotwire, before the GEMS engine

Check the vacuum hose between the fuel pressure regulator and the back of the engine. If that hose has fallen off at the manifold you will get higher than normal fuel pressure. If fuel dribbles out of the vacuum hose the regulator is stuffed anyway. Unless the return line to the tank is blocked, your fuel pump cannot create any more line pressure than that set by the regulator so I'm tipping a faulty regulator or vacuum hose to it. Make sure the return line is not blocked first, loosen the tank's filler cap and blow air down the line to the tank.

Originally Posted by bee utey

Check the vacuum hose between the fuel pressure regulator and the back of the engine. If that hose has fallen off at the manifold you will get higher than normal fuel pressure. If fuel dribbles out of the vacuum hose the regulator is stuffed anyway. Unless the return line to the tank is blocked, your fuel pump cannot create any more line pressure than that set by the regulator so I'm tipping a faulty regulator or vacuum hose to it. Make sure the return line is not blocked first, loosen the tank's filler cap and blow air down the line to the tank.

Thanks for that Bee, I had the return going into a bucket, so that should have removed that from the equation, ill go check the vac hose now!

OK guys.....just tested:

1, black rubber fuel return hose tastes foul, but i could blow air back into the tank.

2, Vacuum hose from rear of Fuel Pres Reg was clean with no deterioration, it leads from the back of the pressure reg to a nipple on the lower part of the plenum almost under the airflow meter, is that correct?

3, Fuel pressure reg was not dribbling fuel and the hose was also clean and no fuel

Maybe its the injectors, maybe the ECU after all, ECU mate said the pump was priming and that the ECU powered up ok and im not getting any fault codes but who knows, the forums said to use a set of refurb 87 mustang gt injectors as a replacement, seeing as you get a whole set for $120, rather than that price each for genuine.

Cheers John

I had the injector plugs tested for pulse by an auto electician, he said they were receiving the signal and we could watch LEDs flash as they pulsed, maybe just the injectors have had it?

ok so the vacuum line is correct, I got my parts mixed up, airflow meter should have been air idle valve, and this kind of injector?

HSV Senator Holden Fuel Injectors VT1 195KW Remanufactured V8 5 0LT 9 97 5 99 | eBay

or this kind.....
http://www.ebay.com.au/itm/Commodore...20003069&rt=nc

Originally Posted by bee utey

Check the vacuum hose between the fuel pressure regulator and the back of the engine. If that hose has fallen off at the manifold you will get higher than normal fuel pressure. If fuel dribbles out of the vacuum hose the regulator is stuffed anyway. Unless the return line to the tank is blocked, your fuel pump cannot create any more line pressure than that set by the regulator so I'm tipping a faulty regulator or vacuum hose to it. Make sure the return line is not blocked first, loosen the tank's filler cap and blow air down the line to the tank.

OK after much thought I'm going with the regulator, surely all 8 injectors wouldn't fail at once, can i use one of these nice adjustable aftermarket jobs or would it be safer to stay stock?

Sard Racing Fuel Pressure Regulator 100 Authentic | eBay

Are the plugs actually firing when it doesnt start?