Rough Starting since new Head Gasket does adjusting AFC help?

[tony597fitter]

I just finished putting on a NEW head (no milling done) with o-rings, studs and a .020 Cummins Gasket. I also installed a set of DDP4s, and reset the timing to 18* as per recomendation from you guys.

Now, the truck has a rough starting issue. I thought it was the timing, so I rechecked it with my Snap-On kit and it is right at 6.0mm lift (215hp pump).

I also thought it was an air leak, (whits smoke, stumbling when started) but I just re-did everything over the summer, new supply and return lines, lift pump, rebuilt heater and pre filter new orings and all, new overflow valve. I pressurized the fuel system yesterday with #8 of shop air and a modded gas cap. I let it pressurize and sit with the air running for about an hour. NO leaks that I could find.
After I was done, I had installed a Holley Blue fuel pump on the frame rail. I thought this would help in the hard starts and I also am going to need it for the twins project.

Now, today it was about 25* out and when I was leaving the hospital (truck sat there since 3:00pm Sat. afternoon about 30 hours) I went to start it, cycled the grid heaters and fuel pump twice, and it barely started (had to crank it twice for about 5-8 sec. each time) and when it finally fired it was like an old piece of diesl machinery, it chugged and popped and blew white smoke all over for maybe 10-15 sec.
The good news is that the timing must be right on because it doesnt stumble anymore when I take off with it.

Is this because of the new head (no milling done) and the .020 head gasket lowering compression?

Also, I have been reading up on the AFC fine tuning. Does the AFC have anything to do with starting since it does control pre-boost fuel? I havent had the chance to adjust it this summer because I was so damn lazy:bang.
It is still set from the previous owner, loose star wheel and AFC screw tightened all the way up, so it pours the black smoke.
Yes, I will be adjusting it, as soon as I can.

 

[golfersmith]

I had a similar problem lat week and found a loose clamp on the supply line. All I had to do was tighten it. I had replaced the lines a few months ago.

May not be your problem since you did a pressure test. What did you use for a modded cap? I need to make one for tests.

 

[Scooter's Roofing]

AFC won't help that... sounds like you were just cold. you sure the grids were working? low timing will also cause white smoke. definately tighten the AFC with the DDP4's. I run mine with just a little bit of lash on the spring.

 

[tony597fitter]

AFC won't help that... sounds like you were just cold. you sure the grids were working? low timing will also cause white smoke. definately tighten the AFC with the DDP4's. I run mine with just a little bit of lash on the spring.

I will go and check the heaters, but I can here them clicking and I can see the amp draw on the gauge.
I just checked and rechecked the timing 6.0mm of lift. I used a new lockwasher this time. I just bought the SnapOn SP500 timing kit, just because my homemade one had me wondering if I set it right sometimes.
What do you mean by TIGHTEN the AFC? Do you want me to tighten the starwheel?

As for the gas cap, just go to autozone and get the cheapest one. All you need on it is the insides (where the thread is). You will get rid of the handle part. You will see what I am talking about once you start pulling things off of it.

 

[tony597fitter]

AFC won't help that... sounds like you were just cold. you sure the grids were working? low timing will also cause white smoke. definately tighten the AFC with the DDP4's. I run mine with just a little bit of lash on the spring.

Again Forrest :thankyou2: :thankyou2:
Went out and checked my grid heaters and only 1 of the relays is powering up. Hope an autoparts store is open in the AM.
:thankyou2: AGAIN.

 

[Loud&Obnoxious]

The lowering of the compression will also make it a little harder to start when cold. Since I put a .20 gasket in my truck, its harder starting when cold and smokes more at idle.