6.9 IP swap -Interesting findings & results.

[BigRigTech]

I swapped the old IP off the 6.9 tonight for the reman unit I removed from the 7.3 in my 94 E350 "junkyard shed".....It's supposed to be 1-2yrs old with low miles. The swap went relatively easy with some interesting findings and results. I hope the pic's of the timing marks can been made out.

Here;s the soon to be installed reman pump.

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Here was the static timing marks on the old pump before I took it off....It was retarded the width of a dime!!!!.....Hence my lazy 6.9.

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Here is where the new pump is timed now.

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As for results, it started easily, smoke was almost nil - nothing like it used to be and it sounds MUCH better....If I wasn't standing in front of the 92 I would swear I was listening to my 91 running like a swiss clock.....I think the low power issue is going to be handled but as I expected to find - the injectors are toast. #3 is sticking open thus letting combustion back into the injector - it boiled the fuel around the injector body when I ran the engine for 2 minutes and #5 has compression coming up around it (bubbles visable in the fuel spilled from bleeding the lines)....The rest seemed ok as there was no visuable issues....I also now have a slight ticking sound audible that wasn't there before, but I'm not too concerned about that until I swap in new injectors in the next week or so as it could be one of them....I'm on the right track to more power in my 92, can't wait to get it done and hauling heavy.

 

[BigRigTech]

Did it ever start good this morning.....But I'm pretty sure my ticking noise is the injector that is sticking open - it heats up really fast - like instantly.......But there was no smoke so that's a huge plus over what it used to be.....New injectors and this thing will be rockin'......The IP has dual return springs - one has to go as it returns to idle in a flash and it's hard to shift this way. Minor adjustments to be made but I can't wait to get this all sorted out.

 

[Jake S.]

They are supposed to have two springs to close the throttle, so if one breaks you have the other to idle it down. The spring is supposed to go on the ball stud where the throttle cable goes on, not like it is in the first pic. the other end doesn't seem right either. My springs are almost as short as they go at idle. That might help a little bit.

 

[icanfixall]

Very true about haveing a dual throttle spring.... Also you need two more injection line vibration dampner clamps on your hard lines... Glad its all going in the right direction... these are really neat trucks when they run up to par or better....

 

[BigRigTech]

The first pic is the old pump, I only one one spring on the 91 - plently because there is a spring on the cable too....If there is clamps missing then they have been gone for a long time...

 

[icanfixall]

The missing clamps on the drivers side fits on the two back cylinders... On the passenger side the clamp fits on thr three back cylinders....I can se the rusty areas in the pics where they fit.. You are very lucky nothing has broken..... Yet...

 

[Ironman03R]

I wouldnt worry about the spring, I drove mine for a year with no return spring because I coulnt find one that matched up right. The IP has a spring on the shaft and the cable has a spring so it had enough pull to keep it from hanging open.

 

[BigRigTech]

I will check the old IP to see if there is any clamps on it, I have some spare lines from another engine too.

 

[Goofyexponent]

Missed out on them injectors last night by THAT much. That pissed me off, but I am looking online for some right now. That and sitting here stinking of ether that I used to wipe off all the undercoating that missed the truck while I was spraying it...

 

[BigRigTech]

Just an update, I ordered a set of reman injectors from Pensecola Diesel today, I paid for the upgraded USPS shipping so hopefully I will have them for this weekend.

 

[BigRigTech]

Good news - my injectors are sitting at the post office for pickup tommorow morning.....I found some line clamps to replace the missing ones....I'm going to tear the old ones out tonight so I can put it back together tommorow once I pick them up.....The duty will cost me $22.78 plus taxes so the total with shipping and duty is $182-cdn....That's about $60 cheaper than the best deal I could find locally.

 

[fastass350]

So from what I gathered, you threw an IP from a 7.3 into your 6.9? I always heard they were different internally, but I take it you aren't having any problems with it? Seems I heard they were timed different inside...but I'm sure someone on here will set it straight.

Chris

 

[BigRigTech]

I think the peak torque on the 7.3 was at 1800rpm and the 6.9 was at 1400rpm. I could be wrong too but the truck starts and runs fine, should be even better with the new injectors tommorow.

 

[Diesel JD]

Hey guys the 7.3 and 6.9 IPs are diferent internally. The main difference is that the 7.3 pump has .0031" plungers whereas the 6.9 has .0029" As far as I can tell they are identical in all important areas such as min/max governed RPM, timing etc., but the 7.3 pump is capable of delivering slightly more fuel. In a stock for stock application they can be considered interchangeable, most pump builders don't feel that way though. I don't know how Mel feels about it but DPS always charged an extra 50 bucks to bring a 6.9 core up to turbo cal specs over a 7.3 core, I don't know if the Moose is the same way or not. I also don't know if the fueling and timing curves are exactly the same with the 6.9 and 7.3 pumps. I have run both and can't feel any significant difference by the seat of my pants, but that means nothing.

 

[BigRigTech]

Hey guys the 7.3 and 6.9 IPs are diferent internally. The main difference is that the 7.3 pump has .0031" plungers whereas the 6.9 has .0029" As far as I can tell they are identical in all important areas such as min/max governed RPM, timing etc., but the 7.3 pump is capable of delivering slightly more fuel. In a stock for stock application they can be considered interchangeable, most pump builders don't feel that way though. I don't know how Mel feels about it but DPS always charged an extra 50 bucks to bring a 6.9 core up to turbo cal specs over a 7.3 core, I don't know if the Moose is the same way or not. I also don't know if the fueling and timing curves are exactly the same with the 6.9 and 7.3 pumps. I have run both and can't feel any significant difference by the seat of my pants, but that means nothing.

I always thought a 6.9 and 7.3 had a slightly different sound - the pump is likely the cause. As long as the 7.3 pump makes the 6.9 a little more angry I will be happy.....It was a **** in it's old retarded state with the orginal IP and these injectors.

I pulled the injectors tonight - no big issues but I did have some fun with one - #5 - all carboned up from compression passing through the washer. it came out in 2 pieces. Can you spot my custom injector puller........No worries about a core charge so I made my own tool for said situation....A 1/2" nut wound on to the injector with a fine thread bolt welded to it to fit my slide hammer. I ground the threads off the injector body to keep it from having any issues pulling the injector out.....Now I just have to fish one washer out - #8 - I can't see in the hole and it's not on the injector.

I also have to find a brush or something to clean the holes out....A trip to home depot or Crappy tire is in order when I head to the post office to get the injectors tommorow morning. One other item to note - look how much soot is on #3 and #5 compared to the rest - #3 was sticking open and # 5 had compression coming up around the body.

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