Chasing idle problem

[xcablb7]

I've got an inter. idle problem with my truck.
Sometimes it fine, smooth no smoke or smell, then randomly I'll come to a stop and blue haze/ smoke starts coming out the idle surges up and down and the exhaust just smells like raw fuel, balance rates are ok.
Could my lift pump be causing this ? Sucking air or inconsistant pressure to the cp3's ?

 

[GMC_2002_Dmax]

If you are running LBZ pumps on an LB7 it could be your regulator scaling.

I would start there.

 

[xcablb7]

Will that cause a random problem ? I've tried a few different tables that others have used succesfully

 

[BALISTIX]

had same problem was a bad injector, drop it into neutral and it would stop, i did that till i changed the injector

 

[DIESELMAFIAPER.LB7]

Have the same issue number 1 injector is out makes it rattle like a sob when I try an get on it so just been putting its been parked while I'm gone but got a new injector coming so

 

[xcablb7]

Great cuz I totaly feel like tearing into it again to do an injector lol

 

[xcablb7]

balistix was your truck doing that all the time or would it come and go ? i'm not sure if i'm getting air in my fuel system causing this or a bad injector. either or, or could be both

 

[BALISTIX]

it would just happen once in a while. we checked for codes and a cylinder misfire was logged

 

[S Phinney]

When it starts doing this at idle take EFI live if you have it and use the DVT to control idle pressure. Ramp up a few KPA at a time to see if smoke clears and fuel smell goes away. If you have luck and I'm pretty confident you will it will be injectors.

Sent from my SCH-I500 using Tapatalk

 

[xcablb7]

Well I ended up finding that my fuel pickup is sucking air, if keep it above 1/2 tank it never happens, but if it drops below it starts to come and go. I drilled holes below my pickup in the bucket so I didn't suck the bucket dry. And I don't have an air seperation lift pump just 2 filters a mallory comp 140 pump and a boost referenced regulator. The injectors may be some of the issue but sucking air is multiplying the problem

 

[Noreaster]

I did a billet pickup & 5/8" line on my truck, I can run it till its dry if I wanted to
or do one of the sumps

 

[xcablb7]

I'm to worried about tearing the sump off, I'm gonna fill the holes in and see if it holds lift pump pressure

 

[juddski88]

If you need a sump I have one James..I wouldn't be too afraid of hurting it

 

[xcablb7]

Ok thx I'll call or text you later