Messed up installing fuel filter - now what?

[jackd]

I've got a 1985 ex-air force Chevy Box van that's basically a G30 with a J-code 6.2l.

I was installing a new fuel filter and I forgot to close the air bleed valve. After trying to start it stopped firing, I realized what I had done, and I closed it. Turned it over and gave it some gas and after running rough for a bit, it stalled. Did it again and it stayed running, but would surge if I gave it gas. Stopped/started and it seemed to be running OK, but with a larger amount of knock than I remember (the engine's always been a little clanky and I'm still not sure how much engine noise is normal).

This morning I decided to bleed it again. Opened the fuel filler cap, water drain and air bleed, disconnected injector, turned over and fuel came out water drain, closed water drain, turned over until fuel came out air bleed (and it wasn't immediate, but only a few seconds. Closed the air bleed, reconnected the injector and it started acting like it was yesterday. I remembered I'd forgotten to re-cap the filler, so I did that and then went through the same procedure I had the day before, so it's running now, but it still doesn't sound right - lots of knock and some "chugging" if that makes sense.

I figure there's still some air in the system, but I'm not sure what I should do next. I don't want to break anything trying to fix it, hopefully I haven't already...

[jackd]

Almost forgot - white smoke on startup, but it's fine once it gets going. I know this is an air-in-fuel-something problem, I just need to know how to find where the air is and get it out without causing any damage.

[DmaxMaverick]

Welcome to the Forums!

Normal. You have an airlock. It will clear itself over time with some running, quicker the harder you run it. An airlock retards the fuel timing, causing the knock.

Or, you can expedite the process by loosening each injector line (one at a time) at the injectors to bleed the air. Can be messy, but it will get all the air out. If it continues to run rough/missing/knocking, check for a leak between the tank and fuel lift pump. If it's sucking air, it will continually pump air through the IP and injectors.

[jackd]

Thanks for the quick reply. This is my first diesel, so I have a lot to learn. I'm glad to hear I can just run it through, I was worried I'd have to drain the entire fuel system or something.

[Robyn]

As long as you can get it to run just take it out and run it.
The injectors on these engines are self bleeding.
Take it out on a good romp and it will soon be just fine.

It may get a little whizzy off and on untill all the air is gone but there is no danger to anything.

Big issue is when you first change the filter. You need to get the bulk of the air out before starting the engine again.

Secret___ Unplug the fuel shutoff from the IP and then crank the sucker untill you have clean air free fuel coing out the air bleed and then reconnect the IP.
You won't pump in a bunch of air this way and make more work for yourself.
With the IP shut off you can crank and not get a lot of air into the IP.

Hope this helps

Robyn