TexasHardcore

Well..today I decided I'd turn up the smoke screw and get a little more familiar with the pump on my truck. Using articles I've printed from various sites, and tips from other members I poked around the pump a bit, but only played with the smoke screw for now... (oh yeah, and practically DESTROYED the little cap that covers it ) Anyways, I have a few questions...

I turned the screw clockwise 2.5 turns, as suggested by the article I printed out. I fired it up...idled for a bit, gave it a few revs, then shut the hood and went for a test run...

There was no change. Nothing. It smokes the same as before..which isn't really much at all.

How far in do you guys go?

Maybe at the meet in Waco this weekend some of the guys can help me "bump" the pump...but I want black smoke to pour out under heavy throttle, and just a little smoke during normal driving, like the other trucks I've seen rattling around.

Anyone wanna enlighten me?

ares

when i adjusted my smoke screw (2 turns) it gave me more power on initial takeoff and a little more smoke when starting. If you want something noticable turn the fuel screw, Not completely sure how much flow your injectors can give you, but you will want to consider some larger injectors.

Alec

Your screw might not even be in contact with the afc diaphragm yet . . .

Take the afc cover off and rotate the eccentric pin to the deepest setting, and you will be able to see how far the smoke screw is extending past the cast stop in the afc cover, and if it is doing anything at all. After increasing fuel with the AFC eccentric, you can start easing in on the fuel-delivery adjusting screw.

I run my "smoke screw" all the way out. It, as mentioned above, has no effect on maximum hp, just how much smoke you generate waiting for the turbo to spool up. Cranking down on it will give you just the opposite smoke to accelerator scenario than what you seem to want. You will have all smoke at start-off, and less at WOT.

furious70

why would the smoke screw all the way in give less smoke at WOT? As I understand it, the smoke screw has no bearing one way or the other at WOT...

My experience has been that without turning up the full load screw you won't see much, if any, smoke. I have my smoke screw in flush with the lock nut and it didn't smoke a lot, not until I broke the collar on the full load did I get smoke....

frostie

I agree. the "smoke screw" on top does not need to be turned in. our fuel pumps (first gen VE) make plenty of fuel at low rpm but lack on the top end. The fuel screw is where your power is, which will make it smoke. The ecentric under the diaphram can be turned to the high spot for a little more fuel on the top end.
You can read the tech article in this forum for more fuel pump info.

Alec

Furious -- I meant less smoke compared to spool-up. As you said, it won't affect smoke once the turbo is spooled up at all.

TexasHardcore

Hopefully this Sunday will be productive... The local DTR & TDR guys are meeting and probably turning some wrenches. I know one of the other 1st gen guys is going to try and do his Gov Spring...Maybe the guys can help me tweak my pump and possibly do the gov spring...I also plan on installing my HX-35/16cm2 Wastegated turbo ... We'll see!

btw: what kind of hp/tq levels do you think I could see with the HX-35/16, BHAF, 4" straight pipe, 3200 gsk, and pump tweaks? I'm guessing the numbers won't be high, but still decent...until I get some injectors, that is. Just curious...