7.3 idi injector pump swap on 6.9 idi

[archerscott]

Good evening, I have recently have picked my self up a 6.9 idi bullnose with a 4 speed manual transmission. After a week of letting it sit, it will no longer start; and after lots of tests I am pretty certain the injection pump went bad on it. Luckily, with the truck came a 7.3idi and I was hoping to be able to use the injection pump from that engine on my 6.9. I am new to diesels and wondering if I could get some pointers on how to go about this? My main concern when doing this swap is the timing, from what I heard I must set both engines to TDC before removing/installing the pump. Additionally, I plan on running through a couple tests on the 7.3 before installing it; therefore will manually turning the pump mess up the timing? Please let me know if you guys have any questions concerns or pointers I am open to everything. Thank you,

 

[Olds64]

She's a straight Bullnose truck!

I would be hesitant to swap an IP, especially if you don't have timing equipment, or a buddy near by that can help you out.

FWIW, I bought a spare 7.3l IDIT but I've never swapped the IP onto my 6.9l. It'd fit, but I swapped the injectors and the engine ended up knocking while cranking. I think one of the injectors was hanging open.

Have you bled your fuel filter and gotten a solid stream of fuel from it while cranking?

 

[archerscott]

Hey olds, thanks for the reply

Yes I have fuel at the fuel filter, fuel at the inlet, but no fuel at the injector lines, injectors, or outlet. I tested the fuel shut off solenoid and everything seems to be working but still no fuel. Which leads me to believe it’s the injector pump.

Any other tests you suggest doing before pulling the pump?

I got a buddy that is going to be and has been really helpful with this project, and I have a timing light and that’s about it.

By what you are saying, I am assuming I cannot put both engine at TSC and swap the pump?

Thank you,

 

[DirtyWood]

Hey olds, thanks for the reply

Yes I have fuel at the fuel filter, fuel at the inlet, but no fuel at the injector lines, injectors, or outlet. I tested the fuel shut off solenoid and everything seems to be working but still no fuel. Which leads me to believe it’s the injector pump.

Any other tests you suggest doing before pulling the pump?

I got a buddy that is going to be and has been really helpful with this project, and I have a timing light and that’s about it.

By what you are saying, I am assuming I cannot put both engine at TSC and swap the pump?

Thank you,

When swapping the pumps DO NOT remove the housing that the pump is bolted to--just remove the 3 9/16 nuts holding the pump.

Timing requires a specific meter with a piezo clamp that attaches to the #1 injector line.

Any chance your near the Central CA coast? I've seen a truck like yours for sale recently in the local ads.

 

[Olds64]

There's only 1 way to install an IP. As mentioned, make sure you don't remove the timing gear housing the IP is mounted to. All it takes is loosening the injection lines and the 3 bolts that secure the IP to the timing gear housing.

 

[archerscott]

Will do.

Just two clarify, I need a piezo clamp to tune the pump to the engine? Or just putting both the engines on TDC before doing the swap could do the trick?

Also, yes I live in Ventura county and bought the truck locally. Unfortunately I bought it as a project already but after letting it sit for about a week it’s even more of a project.

Thank you guys so much for the pointers,

 

[Smitty 90idi]

You can swap the pump just like above. However it will not be timed correctly because every pump wears different and timing is also effected but the injectors. Do time a diesel you need a diesel specific piezo clamp and timing light with adjustable timing or timing box. Neither are cheap but they are pretty easy to use. In my opinion if your going to own a Idi you need to be able to time it since it needs timing about every 50k miles.

 

[archerscott]

Got it,

I will look into ordering a piezo clamp. But just for reference, if I put the pump in the same way I have described how poorly would the truck run and drive? I understand it will be not timed and how that effects the engine but if the timing difference is based on wear how bad would it opperate?

Thank you,

 

[ironworker40]

Line up the marks on the pump and it will be fine. This is how most of these were done as most shops did not have timing equipment to do it.
No need to put ether engine on TDC. Don't remove gear cover just the three bolts holding pump to the gear as others said. Pump only engages gear one way.

 

[DirtyWood]

Without a timing meter setup, which runs about $450 new, best bet is to align the mark on the pump gear housing with the mark on the injection pump and then you can proceed with trial and error. Basically the timing mark on the gear cover and the 12 o''clock timing mark on the injection pump when aligned are enough to get the engine started but may be a ways off from ideal. When the timing is right you should have little or no smoke at startup and not much while driving. If you're unfamiliar with how an IDI should run then it might take longer to get it right but just make small adjustments, drive it, repeat as needed. Remember that the thickness of a dime is about 2 degrees of timing.

 

[Nero]

Without a timing meter setup, which runs about $450 new

I was about to call bs cause I got mine for $200.... Dang, inflation is the worst.

 

[gandalf]

Since you're thinking of messing with the injection system, removing and installing the injection pump, I'd highly suggest reading the following artical, written long ago by Agnem. It has a wealth of information, things every IDI owner should know.

IDI injection system servicing Click this link.

 

[DirtyWood]

I was about to call bs cause I got mine for $200.... Dang, inflation is the worst.

Yeah it sucks. I scored Military surplus meter a while back for about $200.

 

[archerscott]

Thank you all for the response,

I just got the 7.3 pump out and ran it through a couple test and now I am pulling the 6.9 idi pump.

I will let you know if I run into any more issues. If you guys any more suggestions on what tests to run or anything else please let me know.

Thanks again,

 

[archerscott]

Good evening,

The 6.9 IP is out and the 7.3 IP is in. Everything seems to be fitting in fine, except the injector lines seem to be a little off from where they need to line up. Would using the 6.9 lines be a better way to go about this? Or should I tweak the 7.3 ones to make them work? It’s only one or two that really need some tweaking but I am just wondering if the 6.9 lines would just be better in the long run? Please let me know on any input you have.

Thank you,