HELP occasional start - air in lines???

[SEAK]

Posted on dtr and cf too but this is pretty urgent

I resealed my AFC (same procedure as 366 install) and put my stock fuel pin back in over the weekend and have had a lot of trouble once I got it back together.

When we first got the top on the pump the truck started RIGHT UP idle set perfectly then (as we expected) it died cause we had done no bleeding. But it idled for at least a couple minutes before that without me getting on throttle or anything. So we bled it a bit and it started again then coughed and died (like there was air) and then for hours it was just cranking with weak flow at the injectors.

Late last night I noticed my fuel screw was bottomed out so I backed it off and STARTS RIGHT UP idle was a little low but I kept it running for a good two minutes with no coughs or anything. SO started turning the fuel screw back up a half turn at a time and it sounded better and better. I was expecting to hit runaway soon when all of a sudden I was bottomed out. Never hit that before today. And then what do you know truck won't start again. Hasn't started since and there's definitely air in the lines. DO I just keep bleeding to the injectors?

MY HOUSE IS SELLING TODAY and my truck is sitting in the street now I'm supposed to be driving it back down south on monday so that's why this is so urgent I NEED IT MOVING ASAP!!! Please help

[SEAK]

Another thing I may be getting air before my pump. I can never tell when air comes out of the bleed screw above filter no bubbles or anything but intermittently throughout this process I'd crack the nut below throttle linkage where the fuel goes into the VE and almost EVERY time there would be bubble galore coming out of there.... I've checked every fitting from there all the way back to the first filter and everything is tight - all washers are there - no fuel leaking anywhere. ANd we've already bled that a million times....

Also I don't think I broke the lever that the fuel screw rides on... I never reefed on it or anything. Top was reinstalled without the fuel screw in there

[Richie O]

You have tried most of what I would tell ya. If you are getting air in it may be before the filter. Some times there can be an air leak, but at the same time you will never get fuel leaking. I had a bad line on a 89 I once had and the hard start issue got so bad it would crank a long time before it would go. It never did leak fuel, but would let air in.

[SEAK]

How did you locate the leak?

[Richie O]

I just started following the lines. Ended up dropping the tank and saw the issue with my eyes. You can try taking a shop rag and a air compressor blow gun to put pressure into the tank. Just take the shop rag and make a seal with it around the filler neck and add some air. Don't add much because you will split the tank in two. even 5 psi in a tank that size will make a beach ball out of it. When you add ( very little ) air pressure you will cause fuel to leak from the bad area. I have heard of the o ring on the filter/ fuel heater stud causing air to get into the system.

[SEAK]

Thanks for the help I'll try that. I luckily still have my friends compressor from painting the truck... do you just listen or will it actually drip out where the leak is? I've got an electric (~8psi) pump right before my first filter that I've been using for bleeding this whole time and have see no drips from that amount of pressure.

[Richie O]

You should see it leak if its in the line before your pump. Its sounds like your getting plenty of fuel, so it may not be a air leak. Its worth a shot.

[SEAK]

Yeah the only thing I could think is it's before my bleeder pump?? I dunno. The reason I'm still convinced it's air (or something really wrong) is sometimes nothing will come out of cracked injectors at all... I mean it won't squirt up at all. And then a half hour later it will catch and run for a few minutes.

[SEAK]

Well..... I'm never hearing the end of this one.



FUEL SHUTOFF SOLENOID. unplugged. god help me haha

[cmann250]

Been there, done that. Took me a day and a half to figure out why it wouldn't restart after i change the fuel filter. I'm not afraid to admit it, as i come from a 7.3L Power Stroke background, mechanical injection seemed like rocket science at first