M939A2 - 6CTA 8.3L - Fuel screw and aneroid valve adjustment

Рет қаралды 38,875

5 жыл бұрын

Fuel Screw is a 3/8" allenhead or 10mm allenhead. Then you use a 10mm or 8mm socket and loosen the jam nut. Leave the socket on the nut and use a flathead screwdriver thru the middle of the deepwell socket and tighten it a few turns. then Retighten the jam nut.
On the Aneroid adjustment. This will allow you to get power faster before it builds boost. Remove the aneroid plug with a 5/16" allenhead. and Use a flathead screwdriver and turn the gear inside clockwise. This may take a few times of adjusting to get a good setting.

Пікірлер: 24

@garygeer7646 10 ай бұрын

Is there an internal part in the injector pump that affects the idle?

@thomasfry7608 4 жыл бұрын

When you say 'tighten fuel screw a few turns' are these 3 full 360 degree turns? On the star wheel... how do know when you 'have a good setting'?

@garygeer7646 Жыл бұрын

M939A2 no idle. Replaced overflow valve. No air in fuel system. What else would control idle? Any help much appreciated!

@steelreaper8066 5 жыл бұрын

Going to bump mine this summer. Shooting for around 275 HP/300 HP max. Trying to keep in the specs for the MT654CR transmission. My truck is a dog pulling the M322 trailer and a 13,000 lb tractor. Still want a long useful life on the engine but as it is now, it is sloooooooooow!

@wessimpson2794 5 жыл бұрын

Replace the HE1 turbo with an HX40 or HX50. You will be better off and then add some fuel

@Slim_Slid 4 жыл бұрын

@@wessimpson2794 HE1 Turbocharger?

@Slim_Slid 4 жыл бұрын

If you want a long life on your 6CTA,do not make it exceed over 300 HP,I have made the 8.3's handle intense power and I know people who use them in certain rigs for pulling and drag racing.After 300 HP,they won't live long,they will easily walk it off but not go the distance if you want to use one almost all the time.Over 300 HP requires a intercooler,and the cab of the truck needs to be raised at a '5 for it to fit. Easily you can borrow a governor spring kit from a 6BT and turn the fuel screw 2 3/4,and then use the aftermarket turbocharger.If anything else,a ISC has the same bolt patterns and dimensions.

@wessimpson2794 4 жыл бұрын

@@Slim_Slid they are H1Es. Part number 3802257

@garygeer7646 Жыл бұрын

Will this affect the idle at all?

@revvinevan014 Жыл бұрын

My pump is slightly different. Its a 97 f800 with the bosch pump 8.3

@bladenrexroth2555 5 жыл бұрын

I know the military versions came with 240 and 330 hp. What would be needed to crank these up to 400 hp? Same as a 12 valve? Gov spring, injectors and fuel screw?

@bladenrexroth2555 5 жыл бұрын

I've seen marine 6CTAA's cranking out 600+ reliably? I imagine it's possible with OTR 6CT's. It's just an unexplored engine. I imagine these engines have a lot more potential than what we know of.

@wessimpson2794 5 жыл бұрын

Marine injectors. Pump work. Slight governor increase and a bigger turbo

@wessimpson2794 5 жыл бұрын

The more power the less reliable and less life they have.

@bladenrexroth2555 5 жыл бұрын

@@wessimpson2794 I'd be satisfied with 400-450 hp from my 8.3. That should be a reliable rating with the 8.3. 160-190 hp 5.9's are pretty reliable tuned up to 300-400 hp. A sleeved 8.3 should do pretty well at 400-450?

@Slim_Slid 4 жыл бұрын

@bladenrexroth2555 I owned a 1991 M931A2 that had 450 HP/1,200 TQ. Injectors,fuel screw,fuel pump,and HX50 turbocharger added after the intercooler and governor spring kit from 6BT were installed. I have had idiots say that 6CT's can't go over 300 HP...YES they can.But if you want that,the 6CT will handle the stress.Some of them used for truck pulling or diesel racing have twice that amount of power if not more,but obviously are one trip at that point due to a short life span.I would think that the 6CT should remain humble even at 400-450 HP though. I know you can use parts from a marine 6CTA as interchange if you want more power out of them. For the 6CT too,use parts from a ISC,they have the same bolt patterns and dimensions.

@kylewiersema9628 3 жыл бұрын

How far out have you backed the screw on the top of the pump as you talked about also have you adjusted the rear fuel adjustment on the rear of the pump? If so how far out did you back that jam nut

@65Red 2 жыл бұрын

Most back out the front screw just a few turns. You’ll know if you went too far if it smokes too much off idle or if the screw hits the inside of the pump housing. If it does hit the inside, it’ll hang the throttle. Run the throttle after you adjust it to make sure it clears. As far as the rear preload nut in the AFC housing, I’ve always heard to back the nuts out until the top of the locknut is flush with the stud.