POD's in

[bvanetten]

Fineally got the POD's in. Here's how it went...



First some backround info. 1990 CTD, 2nd gen intercooler, 89% DTT, Timing untouched, full power screw turned to the coller, 12cm housing.



First I installed the POD's, bled 3 lines and it started up. Drove it around and noticed more smoke and a bit more power. But not the crazy kind of power others have talked about.



Then I turned the smoke screw 2 turns clockwise and adjusted the excentric on the diaphram to it's most aggresive position... Better launch and even more smoke... a bit more power.



Next I did timing. I don't know for sure where it was set but based on how the rest of the truck was setup it is probably real close to stock. I made a mark on the pump and the housing and moved the pump about 1/8th toward the motor. Now it smokes a bit at first and clears to a light haze when boost comes on.



A few observations.

I still only have 20 to 22 pounds boost.

Better launch

Same EGT's

At idle it has a bit of a stumble, like its missing.

Idle rpm dropped.



A few questions.

Should I have more boost?

Shouldn't my EGT's clime faster and be higher?

Should I remove the collar on the full power screw and turn it up more?



Update. Injector #6 is leaking a bit at the line. Could this cause my stumble and miss? I'll tighten it tonight.



Bruce

 

[Rick Comenzo]

Bruce, I also put my POD's in recently, I have the same egt's and boost,but much more blue smoke at idle-hot or cold. My 93 has a 14 cm housing,I also moved my injector pump 1/8 inch towards the top of the engine. I notice better launch, I don't like all the blue smoke at idle, at full power some smoke but OK. I also notice lower idle rpm's and ticking sounds from the injectors now, any suggestions as to lower low rpm blue smoke? Thanks Rick.

 

[Withers]

POD's

Hey guy's, i'm having some of the same problems as you guy's. Not so great off the line, minor smoke problem, wot about 1100f, 22-24 lbs of boost, some " ticking" might be injector noise? . The problem with me is i have nothing to compare my truck with, i read on some posts where you have to re learn how to drive the truck, i'm not having this problem. It's going back in the shop in the next couple weeks, so hopfully it will get figured out.

Bvanetten i think you should have a few more lbs of boost, i belive the egt's will climb faster and higher, and the stumble i would think that would be retarted timing, but i'm far from being a machanic. Please post your results as i'm very interested in the out come, thanks.

 

[BushWakr - RIP]

Hey Ken,



I'm surprised that you do not find an impressive difference.

I found a noticable difference even from the 180's I had in to start with.

I also have the 'blue smoke' at idle warm/cold.

I have found that some of the things that affect it are who's fuel I'm using, (mohawk is the best so far) were my full fuel screw is, were my starwheel is, and a bit of were my diaphram is.

It is really a balancing act. If want large power I can turn the full fuel screw a 1/3 turn and hang on.

Spoke with Piers last week. He wants to try 20 thou. washers in my truck. He says he's had some success with those in 1 or 2 others.

I'm personally thinking of upping the pop-off around 10 bar to see if that helps with idle smoke/smoothness.



Lets keep this thread updated as we go. Since there aren't many of us 1st Gen's left in here, every bit counts.



edit: Ken, the 18. 5cm housing is pretty doggy to begin with, the 16cm or even better the 14cm will really improve your spool-up which, I would think, will make a difference in getting into the HP zone and turning the tires. Only issue is a 'possible' EGT issue at the upper ends.



Bob.

 

[Rick Comenzo]

Bob,Do you think changing the copper washers will help? I used the . 093 washers on the PW injectors and the POD injectors, all the same as the stock factory injectors. How does one raise the BAR on injectors?I am seeing 22-24 psi with the 14 cm housing and 1000 degrees on the pyro with a hard pull, I added a twin ram intake for more air to hopefully cut down on smoke as we have smoke opacity tests here. Thanks Rick.

 

[bvanetten]

Update

Ok. It looks like I had two injector lines leeking a bit. I've been told that even a very slight leak, more of a weep will effect line pressures and cause an injector to not pop off right. This causes a "lope". The tail pipe sounded like a big block! So I tightened the lines and it didn't help at first. Also, I took out the full power screw and removed the collar. Remember I had the screw turned all the way to the collar. I marked where the set screw was and turned it in one turn past where the collar was. Idle went up, lope went away (probably because of high idle, I'll kick the idle down tonight and see) and power went UP,UP,UP. She hauls some but now. I'm probably going to back the smoke screw out one turn to help with smoke a bit. I STILL DON'T HAVE ANY MORE BOOST! I'm really starting to suspect a bad gauge.



Some stats:

Peek EGT's with a 0 to 60 WOT run (power break to 5 psi) = a bit over 900, 22 lbs. boost.



What do ya think...



Bruce



PS. I don't have the option of running different size washers. The POD's have 7mm tips and the non-intercooled CTD's ran 9mm tips. I have to run a copper tube-washer-adapter-thingie from Cummins.

 

[BushWakr - RIP]

Rick,



Here's my take on the 'washer' issue.

Remember I'm still in the learning phase on some of this too so I'm NOT willing to take a 10HP penalty if I make a misstatement.

The POD's have a slightly larger spray angle than the stock or 180HP injectors. This causes some of the fuel cloud to overshoot the piston bowl (my term). . keep in mind that the bowl is the hottest part area and is were the fuel is meant to be burned.



Also, the POD's are referred to as "large sac" injectors. (Boy, Piers is gonna have to start paying me for this )

So, as I understand it, the thinner washer will allow the nozzle tip to move just a bit closer to the bowl and result in less "overshooting" (again, my term) ... second because these injectors are "large sac" they retain a tiny amount of fuel in the tip after injection (due to lower fuel pressure at low speeds/idle)

This 'retention' and subsequent release in a slightly coarse form causes some unburnt fuel to increase smoke.



Piers suggested a test to confirm this which I did. And it did work.

I took the ole' dog out for a hot arse run, getting it good and warm, then hauled my butt to the side of the road and slid to a stop. While the EGT was still high and coming down I had little or no smoke, then, as the EGT cooled the haze at idle started to show.

His point was that at higher temps/pressures the smoke is gone or reduced, but returns once cooler temps return.

As I understand it, to increase the pop-off pressure you need to dissasemble the injector and change shims/spring(s) inside which hold the injector closed longer, allowing pressure to build before release. Atleast, that's my rookie understanding of it.

My thought was that if the pressure was just a bit higher, then at idle it might help with atomization, just like when you bring revs up. Again, thats how I interpreted the information, rightly or wrongly.

When I went from the 95 thou washer to the 65 thou I saw an improvemnt. I wonder if the 20 thou will help a bit more.

My boost went from about 21psi with the 180 BD inj. to around 26psi with the POD's without any change of settings.



bvanetten,



If you cannot use different washer then perhaps your next (only?) option would be to try increasing the pop-off pressures a bit.

I have found my setup particularly sensitive to diahpram adjustments. A slight change to this make a noticable change in smoke at idle. I guess I need to back off on the starwheel more. My 'smoke screw' is already backed right out, and does not make contact with the diaphram.



Well thats it. Hang in and keep lookin/working on it.



Bob.

 

[Rick Comenzo]

POD Injectors

Bob, Thanks for the reply, I will try changing copper washers. Piers supplied me with several thickness washers to use. Also my pump settings are near stock(diaphram and power screw). I guess I will have to make some trial and error adjustments. Rick.

 

[Excessive Force]

GOT BOOST?

With the P. O. D. injectors, pump turned up 1. 5 turns,4" straight pipe from downpipe to 2' behind cab ,i get 41# of boost at W. O. T. Gotta watch the E. G. T's though. :--) :-laf

 

[bvanetten]

41# boost? Man, I must have a bad boost guage. The thing won't go over 22# and I got ALOT more power.

 

[Dfeland]

intercooler

You might want to check your intercooler for holes. I know myself and others have had many holes in their coolers that sounded like a jet engine as the air bled off.

 

[backroad]

Leaks are possibility...

I believe that there is a strong possibility. I have a mechanic up here in Dewey that you might want to be talking with. He has a tool (just past the patent process) that is able to presurize the air system and checks for any leakdown. He's told me in the past that it's amazing how many boost and power problems come from these air leaks.



If you're interested, his business is H & H Diesel up North of you in Dewey. His business is located at his house and he does work on weekends. Phone number is 520-632-5317. Just a good ole' boy straight shooter.



Dennis in Dewey (backroad)

 

[Power Wagon]

Originally posted by bvanetten

Fineally got the POD's in. Here's how it went...



First some backround info. 1990 CTD, 2nd gen intercooler, 89% DTT, Timing untouched, full power screw turned to the coller, 12cm housing.





A few questions.

Should I have more boost?

Shouldn't my EGT's clime faster and be higher?

Should I remove the collar on the full power screw and turn it up more?



Update. Injector #6 is leaking a bit at the line. Could this cause my stumble and miss? I'll tighten it tonight.



Bruce

I figured out, when I read farther down at another post, that you have a pre-intercooled engine, with an intercooler added - that it came with the larger tips. This is why you're not seeing a large difference. The early engines had large injectors, and moving to the POD injectors isn't a big deal.



What's holding you "back" is that the early pumps were set MUCH lower than the later ones. So, the trick here, is to set up the fuel with the screw.

 

[bvanetten]

Dfeland,

I have had holes before. One was as big as a pencil! Even with that hole I could still muster up 18 lbs of boost! I made a plate that bolts up to the manifold in place of the turbo and plumed an air chuck into a 2 inch pvc end cap that goes at the turbo inlet. With this I am going to check pressure again.



Backroad,

I might have your guy check it anyhow. This will help verify my #'s



Powerwagon,

Yeah. It's a 1990. The 89 and 90 model years were the 1st of the 1st gens right? I'll keep tweeking the pump until I like it. The full power screw is about 1/2 turn past where the collar was. To much? Do I have more safe usable room? I can probably back off of the power screw a bit also. I want all of the power and none of the smoke Heres a question fo ya. With the 94's and up there are two different power levels based on whether of not your a stick or an auto. Was this done in 90? The motor I have had a Getrag behind it. So what HP pump do I have, 160 or something else.



Bruce