6.9 to 7.3 Injection pumps

[rodymartin]

Can the 7.3 IP be used on the 6.9?

 

[h2odrx]

Yes and no?

 

[Diesel JD]

Yes! I'd use it with no hesitation at all....in fact I do have a 7.3 pump on my 6.9, it works great.

 

[moneypit]

How 'bout vice versa? (6.9 pump on a 7.3?)

 

[RKOCH]

6.9 pump on a 7.3 is too lean.

 

[Diesel JD]

I think he means you're leaving a lot on the table with a 6.9 pump on a 7.3, not lean in that it will kill it like lean seizing a gasser. There's validity in his point. The 6.9 pump uses .0029" fuel plungers, the 7.3 pump, .0031" and the John Deere DB4 uses .0033". That said if I had a stock 7.3 truck I'd throw on the 6.9 pump and not expect to see much of a performance drop.

 

[RKOCH]

I was given a 6.9 pump one time by accident and put it in a 7.3 and was a total pig... Checked the numbers found out what happend and they replaced it night and day. But won't kill your motor.

 

[h2odrx]

I've got a 92 7.3 pump on my 6.9 and love it!

 

[k_williams1982]

I had a 7.3 pump on my '88 non-turboed 6.9 and it ran fine, but blew ALOT of black smoke while pulling grades and under hard acceleration. I replaced it with a 6.9 pump and the smoke cleared quite a bit. I don't know it it "over-fueled" my engine because of it not having a turbo or if maybe the 7.3 pump I had was malfunctioning. I have a 6.9 now with a turbo and I don't have the black smoke problem anymore on the grades or under hard acceleration, but I don't know if the current pump is a 6.9 or a 7.3, but was told it's still the 6.9 pump.

 

[Agnem]

6.9 pump on a 7.3 is too lean.

Tell that to Lady Moose.

You can use either on either, especially if you are going to play with the fuel screw. The calibation (part) numbers mean nothing once you touch it.

 

[RKOCH]

The size of the fuel pluggers are smaller a 6.9 pump will never supply the same amount of total fuel in the end. You turn the screw and allow the plugger to come out more but if my plunger has a larger dia the I have more fuel @ the same stroke.