Turning Up A 6.9 And 7.3 Mechanical Motor
 

"Lots of guys have at one time or another wanted to know how to adjust their Stanadyne DB2 fuel injection pump on an idi 6.9 or 7.3 diesel engine. It isn't really difficult to do, but I recommend not messing with the stock setting unless you have a pyrometer. It doesn't take much to overfuel a stock naturally aspirated engine, often with disastrous results.
Safety as always is important. On that note, probably the first thing one should do would be to disconnect the batteries, to ensure there is no power to the pump, or at least remove the wires so that if/when you rotate the engine, it will not start. The adjustment screw lives within the pump, but can be accessed through a little door on the passenger side of the pump. It is triangular in shape, and is held in place with 2 small bolts, and a gasket underneath to seal it. It looks like this.You will want to have either a shallow dish or a bunch of rags under the pump when you remove the plate, as about a pint of diesel fuel will spill when the plate comes off. The next thing to do is to turn the engine to align the adjustment screw internally. This can be done one of two ways that I know of. 1. You must put a large socket (15/16'ths) on the bolt on the front of the crank pulley. Rotate the engine till the timing mark on the vibration damper is at about the 1 o'clock position as seen from the front of the engine. This should line up the insides of the pump so that the adjustment screw will appear in the opening behind where the cover plate was on the pump. Since the crank turns twice for each one rotation of the injection pump however, you may get the timing mark to the 1 o'clock position and still not be able to see the adjustment screw inside the pump. It would look like this. (A small dental type mirror may help to see inside the pump here because of the angles etc)... If you look in and cannot see the adjustment allen screw, you must rotate the engine 360 deg. or one full rotation clockwise, till the mark again lines up at about the 1 o'clock position, and then you should be able to see the screw, and it should look like this. The other way to align the pump, is to take the cover off of the front of the injection pump cover housing. Inside this is the bolts that hold the injection pump timing gear onto the pump. There is also an alignment dowel. If you rotate the engine till this alignment dowel is at exactly the 12 o'clock position, then the adjustment screw will be visible through the opening behind the cover plate. Here's a pic of the opening and the dowel, but with the gear-to-pump bolts removed, and the dowel is at the 4 o'clock position instead of the 12 o'clock. Ok, now, all that is required is to get a good quality allen wrench which fits the adjustment screw(5/32) in size. The adjustment screw has locking threads, so make sure you have a good wrench, 'cause you don't want to damage this one or drop little bits of metal shavings inside your pump. To increase the fuel setting, it is generally recommended to go in small increments. Usually 60 deg. rotation, which is about the same as turning the wrench one flat, or 1/6'th of a turn. Clockwise will increase the fuel setting, counterclockwise will decrease the fuel setting. Put the cover plate back on, being careful not to overtighten the little bolts, replace the wires on the pump, and go for a run to see how it goes. Don't forget to watch that pyrometer!! Good luck with it." quoted from a website, brought to you by me, Logan.

great info Logan.... how do you come up with all this stuff....

i found a page that had how to turn up about every domestic mechanical diesel motor out there, thats where they all came from in the Big Rig section, and in these sections, the mercedes stuff i just looked on google.

can you put a 84 diesel motor in a 94 diesel truck

why would you want to replace a 7.3l with a 6.9l?:c:

i just to use the block the motor in the 94 truck is crack i have a block in the 84 ford truck will it work

well that would be a good reason:c:

will the block work yes or no

I believe so. I had a guy put one in an old tow truck years ago.

Great Info there Logan Thanks !

Great Post!

i was wondering what a safe exhaust temperature would be for my 93 non-turbo. i dont want to put in too much fuel and end up burning holes in my pistons.

I followed every step except getting the pyrometer and it worked great. it was pretty easy to do with some help from a buddy. i can feel the power gain on the hills and it blows black smoke.

:U:so how much smoke did it blow. how bad did it hurt your fuel economy??

Yes a 6.9 block and 7.3 block will interchange. And the 7.3 block is better cause it has stronger cylinder walls. And i also turned up the injectioin pump in my truck. i liked the gain, and yes it does blow a little bit more smoke. But its sweet!:ok1:

the idi engines both interchange, and on the outside they are identical. so as long as the 94 is not a di powerstroke do it. some people actually prefer the 6.9 because the cylinder walls are thicker. but this only matters to engines that have suffered severe cavitation. 7.3's are more prone to cavitation problems because there cylinder walls are thinner. i hope everyone is using coolant SCA's to prevent this.

So if i put a three inch straight pipe, better flowing intake and turned the fuel pump 1/6 of turn clockwise how much of a power increase would that be around? Would anyone by any chance know?

I did basically all wat u said, but wit 4inch exhaust and advanced my timing 5 degrees and put on electric fans. I dyno'd my truck and put down 150HP@2860RPM and 320LBS/FT@1840RPM. Mines a stick and thats with 33inch tires.:rocking:

Oh allright, mine is an automatic and it came from the factory rated at 170hp and 338ft of torque at 1400rpm`s. So by doing all of the stuff I mentioned earlier how much of a power in crease would that be?

about 15-18 hp and 30-40 ft lbs of torque

That sounds about right for the gains! I noticed a difference!:U:

1/4 turn on the roller to roller will net about 10% more fuel.

So a ten percent fuel gain is guite a bit of a gain im guessing right?
So by also adding 30 hp injectors to it, straight pipe, intake and turned the fuel pump a 1/4 of a turn, how much pwr would that add up to be in all?

Im guessing around maybe 50 hp and 100-120 FT right?

I would prob guess around that, but that seems a bit high for the torque??? If u dont have a turbo u prob wont see that big of a gain. You'll prob end up drowning the engine with fuel and not c much of an increase. But were would u get injectors like that??? I can't seem to find any!!

its very easy to over fuel an idi. especially with bigger injectors and even with a turbo. as long as you see black smoke you have too much fuel. also these engines run hot too. so i would keep a close eye on the egt. i found with my 94 turbo i can get more than enough fuel out of the stock pump and injectors with a max boost pressure of 14psi. and it will climb past 1200 degrees if i dont watch it.

Whats the max you can "safely" turn the pump up?:choochoo:

So the gains for my truck would be about 45 hp and 75 foot pounds of torque?
Because I want to get a 4 inch straight pipe, bigger injectors, different air intake and turn the fuel pump up a half a turn. If im gonna turn the fuel pump up at all, im definetly going to be buying a pyrometer. Yeah, only having 135 hp and maybe having 300 foot pounds of torque definetly aint gonna cut it.

"Rotate the engine till the timing mark on the vibration damper is at about the 1 o'clock position as seen from the front of the engine."
:argh:
Im not exactly sure what that means :pca1:

Everybody is talking about different air filters, where do you get them, or are they just talking about a K&N drop in replacement?

WHATEVER YOU DO DONT TURN UP THE IP UNLESS YOU HAVE A PYROMETER
If not you risk blowing holes in the pistons and owing up your motor. The N/A IDI is very sensitive when it comes to this and there is very little rom for error. If you have a turbo, larger exhaust and a free flow intake such as a ramair setup these will help keep the EGTS down.



Yes you can, if it were me I'd stick with a 6.9, seeing as you don't have to worry about the cavitation issues
1200 for a minute or so would be as high as I'd ever push mine, anything above 1250 for an extended period of time is basically suicide
If your looking for a ton of power and mods you've got the wrong truck/motor combo, the IDI is no power house by any means. I've seen a dyno on a 83 or 84 F-250 with 6.9 and a banks turbo and that thing barely made 200hp to the wheels, if you want extreme power go with a powerstroke, or a P pump Cummins. If you want reliabilty and a good work horse stick with the IDI

The Harmonic Dampner that is mounts on the crankshaft has a timing line on it, usually a scribed mark across the width of the dampner, so what this is saying is that you want that timing mark to be at the one o'clock position if you were to be looking at the from t of the motor straight on, the reason yu want it in this position is because the Max fuel screw under the cover of the IP is visible when the mark is like this IIRC.

Hi

Will this principal work on my bakkie.Its a 2.5l isuzu.It also has his access window on the side of the pump.I have moded all the basics but the mechanical diesel pump still remains because i dont know how and cant find any one that knows how.

I was always told that if a Diesel smokes it is not burning all the fuel, in other words it's wasting fuel, blowing it right out the exhaust. My truck rarely smokes and has plenty of power.

---AutoMerged DoublePost---

My truck has a 6.9 with a second generation Banks Sidewinder Turbocharger on it and I replaced the 4-spd with a 5-spd. transmission.

Thats true, these guys you see blacking out roadways are wasting a ton of fuel. Thats not to say there isn't any benefit to turning the pump up. I turned my pump up 2 flats and my truck doesn't smoke under normal driving but will smoke a little if I push it. It has a little more power and hasn't affected my MPG at all. :U:

I turned mine up 2 flats an noticed nothing.. so i went a 1/4 turn and very little difference..

by the time I was done turning little by little by little and seeing nothing I got mad and just cranked the screw all the way in then backed it out a half turn :tu:

would smoke real heavy under a load (or WOT) otherwise it ran clear, with much more power, and no ill effects, this motor has 209k on the clock and ran like this for a year until someone hit me and flipped it, sold the remains and it's still running powering the frame with a backhoe attached to it. :choochoo:

get an EGT gauge if your worried, but i've seen numerous 6.9's running like this for years without burning up.

can i mechanically turn up my 1997 powerstroke????

---AutoMerged DoublePost---

can i do this to my 1997 powerstroke?

no.

does anyone know how you could put something on like a regulator to control the fuel after you turn it up so you could turn it up or down as needed i have a 94 7.3 turbo idi

I turned mine up 1/4 turn and had a nice amount of smoke and still got 20 mpg...just recently turned it up to 3/4 of a turn...16 mpg and a hell of a lot of black smoke...people hate getting behind me now...lol

What are coolant SCA's?

Additives put in the coolant to prevent block cavitation. Not as big a deal with the 6.9 since it has thicker cylinder walls but still needs to be addressed, more so with the 7.3. This article will explain cavitation and what the SCA's do.

Cavitation Article