Loosing Prime / Crossover Tube O-rings

[Mopar1973Man]

Kind of like myself the +75 HP DAP VCO (7 x 0.0085) injectors only made about 75k miles and were wore out and popping low. Typically what you'll see is the engine load drops seriously low at about 3% and the idle is excessive high like 850 to 900 RPM's that is pop pressure is TOO LOW. The ECM can't cut fuel morre, so the idle creeps up and the engine load is botttom out because it can't cut fuel. 

 

293 Bar (Bottom limit) <-> 300 to 305 bar (common for aftermarket) <-> 310 bar (stock pop) <-> Greater that 310 bar (MPG and longevity)

 

Like myself I'm popped at 320 bar on my 7 x 0.010 injectors. Touch 22 MPG once in awhile. I'm down to about 7% engine load at idle from the 13% I had originally when I installed so I'm about half life with these injectors. About the first 20k to 30k it stayed close to 11 to 13% but now starting to wear and lose its pop pressure at miles are racked up 1,000 miles per week. 

[pepsi71ocean]

22 hours ago, Mopar1973Man said:

Like myself I'm popped at 320 bar on my 7 x 0.010 injectors. Touch 22 MPG once in awhile. I'm down to about 7% engine load at idle from the 13% I had originally when I installed so I'm about half life with these injectors. About the first 20k to 30k it stayed close to 11 to 13% but now starting to wear and lose its pop pressure at miles are racked up 1,000 miles per week. 

 

I really like the higher popped injector pressures on my truck. I really think that all injectors should be popped higher, especially the larger ones. It really helps with pre-boost spooling. Even with my smarty it helps with the pre-boost spooling better then adjusting the TM and D' numbers.

[dave110]

11 hours ago, pepsi71ocean said:

 

I really like the higher popped injector pressures on my truck. I really think that all injectors should be popped higher, especially the larger ones. It really helps with pre-boost spooling. Even with my smarty it helps with the pre-boost spooling better then adjusting the TM and D' numbers.

Pepsi, you're at 320 right? I've read that high pop pressures can cause hard starts in cold weather. You and I are at the same altitude and area at least when you're in Reading. Any trouble cold starting in our winters? Curious because injectors are on my short list and I'd like to try higher pop pressure.

 

I just noticed your sig. and I see your popped at 322.

Edited October 11, 2019 by dave110

[Octafish]

Update:

 

Injector shop built me some 150hp's.

New BD nozzles (has 8 holes).

Popped at 320.

 

So new sticks, O-rings, O-rings for cross over tubes.

Downloaded Moparmans Economy Tune.

 

I haven't driven it much but I'm super impressed.

Lower EGT's than my 100hp's.

Quieter, smoother idle.

 

I parked it nose uphill and I'll check it this evening to see if I've fixed the lost prime issue.

However I am hopeful!

 

Now, I've got to upgrade this HY35.

Suggestions?

Edited October 14, 2019 by Octafish

[Mopar1973Man]

19 hours ago, Octafish said:

I haven't driven it much but I'm super impressed.

Lower EGT's than my 100hp's.

Quieter, smoother idle.

 

Impressive. At least there is now confirmation that 150 HP @ 320 bar is a good combo. That 8 hole should be good for MPG.

 

Tidbit... The winter time offset should be about -20*F from engine oil temp and coolant temp. Still batting good 20+ MPG yet with temps already in the +10*F in the mornings. 

 

19 hours ago, Octafish said:

Now, I've got to upgrade this HY35.

Suggestions?

 

62/68/12 would be a good turbo (no exhaust brake). Might need to tweak the fuel map slightly to control smoke.

[pepsi71ocean]

On 10/10/2019 at 8:38 PM, dave110 said:

Pepsi, you're at 320 right? I've read that high pop pressures can cause hard starts in cold weather. You and I are at the same altitude and area at least when you're in Reading. Any trouble cold starting in our winters? Curious because injectors are on my short list and I'd like to try higher pop pressure.

 

I just noticed your sig. and I see your popped at 322.

 

I didn't have any issues going down to about 20f, and that was about when I downed the truck for mechanical work.

 

I did have issues at first with starting, but I can't tell if it was transmission related or engine related, but they did go away. The truck stalls allot, but I had to drop my valve body as it wouldn't do it in manual 1, only drive. Now to be fair, the truck did this as well beforehand with the injectors before I pulled to get them popped. 

 

The truck idles smoother and runs like a raped ape I can assure you that. 

[pepsi71ocean]

3 hours ago, Mopar1973Man said:

 

Impressive. At least there is now confirmation that 150 HP @ 320 bar is a good combo. That 8 hole should be good for MPG.

 

I do believe it's correlated Mike. As I told you on the phone, popping 50hp injectors at 325bar I think will cause a issue, but larger injectors such as 150s will thrive at 325bar. 

 

 

I think there is a safe range for higher pop injectors based on the size. There later the size the more the slack you can take out of it. 

[Octafish]

3 hours ago, Mopar1973Man said:

 

Impressive. At least there is now confirmation that 150 HP @ 320 bar is a good combo. That 8 hole should be good for MPG.

 

Tidbit... The winter time offset should be about -20*F from engine oil temp and coolant temp. Still batting good 20+ MPG yet with temps already in the +10*F in the mornings. 

 

 

62/68/12 would be a good turbo (no exhaust brake). Might need to tweak the fuel map slightly to control smoke.

For my driving style, this may be the ultimate tune for my setup.

I feel like I have the best of both worlds. Power and economy.

The truck has more than enough power for a daily driver.

And I'm very anxious to check mileage on my next trip.

 

And thanks for the turbo recommendation.

Do you know of a turnkey kit available out there?

I'd like to make the swap as painless as possible.

The HY needs to go.

 

 

It now holds prime just fine.

Perhaps the injector 0-rings were the problem.

They were very flat, therefore the old injectors had no resistance when removing them from the head.

[pepsi71ocean]

@dave110 if you're not in a rush. Give me a few weeks to put the Dodge back together and you can take her for a spin and see how the motor handles. I'm being told it will be a cold winter.