[brookwood61]

Hi- I have an 86 720 with the Z24I, that I keep around. I had fuel pump problems, so it sat without gas for a while. When I turn on the key, with the engine off, I can hear a squealing sound coming from the throtle body. I was checking for gas leaks, and when she would turn on the key, I would hear the squeal, as the throtle body was filling up. The truck was off, and it was deffinatly coming from the TB.

Today the truck started missing, and I can smell gas while running. It is putting out a small bit of black smoke too, like too much gas at an idle.

Any help appreciated. Thanks!!

 

[zanegrey]

check the fuel pressure regulator on the tbi..

 

[brookwood61]

Thanks for the reply. I found some time to read up on it, & work on it over the holiday weekend. I had a spare TBI, so I put it on. The truck won't start, but will run if gas is put down the throat. Now, I am getting just a small amount of gas, out of the return line, and there seems to be plenty of fuel pressure. Without the truck running, I have to slowly bleed the pressure off the line, going in.
I can't find my fuel pressure tester. Should I have a good flow of gas from the return line, with the pump running, and the truck off? Gas is flowing slowly thru the regulator, and there is line pressure going in, enough to spray when taking the line off.
This TBI hasn't been on the truck in about 9 years, so it's probably gummed somewhat. Would you have any advice, until I can find my pressure tester?
Thanks

 

[zanegrey]

make sure you are getting electric to the injectors...

 

[brookwood61]

Thanks. I'm home for lunch for a few. It did all mentioned at first(chugging,black smoke, gas smell in exhaust), then it wouldn't start at all. Time to start checking conections, and grounds again. I didn't really notice if the injectors were pulsing or not now. Somewhere, I read that I should have a decent gas return flow, that shows I am getting enough fuel for the injectors. What I have now is more then a trickle, but not much more. Going into the throttle body, I have good flow.
Is there a way to test pump pressure, without the truck running? Every test I read is done with it running.
Thanks

 

[brookwood61]

Well,I finally got around to changing the pump.I put one from an Audi,that I knew was good,and about the same specs.A practically new Bosch fuel pump,that a friend donated.I had to change the banjo,that was it.I have plenty of flow now,but it still won't start.Tomorrow,I'll put the throttle body that was on it back on,with the new regulator.From what I can see,the pump was weak,and the regulator was shot.It did have gas in the vacuum line to it, and had a heck of a squeel,like zanegrey mentioned checking out.
One darn Nissan dealer wanted $78 for the 2 throttle body gaskets,and no one in Columbus had them,except for more $$$ special order,but no way near the dealer price.Evan Advance's special order was a no-go.Red's cutting me a pair now,out of gasket material.
Maybe it will come to life tomorrow.