Results from my testing today

Big Swole

Big Swole

MegaInterceptor
Joined
Jun 28, 2007
Messages
16,950
Been chasing a loss in power lately as some of you know. Had some bad luck over the last couple of months with this thing...

Broken Input shaft right after my first trip to the track after the build...I may have injured it when I accidently locked my TC in 1gear on one of the passes....Anyway, it had been running awesome..best being my 11.47@117.88mph.....That calculates right around 790 on #2 only given a pretty accurate weight used....

After replacing the broken shaft, the next time at the track I had lost quiet a bit of power...three different times at the track only netted me right around the 12.00's at 111-112 mph....That is almost a loss of 100 HP.

Then I had the Htt turbo issue(s)...one, the pucks were getting stuck against the WG housing due to a bent/broke arm....two, I also had the thin plate on the WG that got warped and was blowing exhaust down on my S480....Sent it in a they did the temp. fix until the new fix gets online....

I did a complete Reflash of my ECM from a buddy that works for Dodge and nothing changed...

Well, started thinking I may have busted an injector or something....I've started getting more smoke and it's not cleaning up like it used to...Spool up is slower as well.....Went to the dyno day her in GA last Sat.....Did 691, 693, & 689......So, we confirmed that I still have an issue after the turbo was repaired......My Rail pressure is not the problem either cause I can hit 25K at WOT with my MP8 completely off...and 27.5K at WOT with MP8 on 100%

So today I pulled my injectors to send and get tested!!! But I did two things just to set my mind at ease..

Ran a bore scope down into the cylinders thru the injector hole...ALL cylinder walls, pistons and bowls look fine!!! It was a little difficult to see every little bit due to the fluid that falls in when the injector is pulled.......

Then, I did a complete compression test on all cylinders......I asked Jeff before I started what I should expect since my Piston's have been cut by a FULL .100......I think stock is around 470psi.....Jeff said he thought I'd be right around 375 psi.........Well, here's what I found:

#1 = 375 psi
#2 = 375 psi
#3 = 390 psi
#4 = 350 psi
#5 = 375 psi
#6 = 390 psi

Jeff said that everything was within spec.....I was a little worried about #4 being down a bit from the others..but Jeff didn't seem worried about it at all.....PLUS 25 psi down on one cylinders is NOT enough to lose 100 HP....

So, we totally ruled out ANY possible issues with my motor....Any Head gasket, Valve seat, Valve, piston, or ring issues would have shown up durring these test.......SO, it has to be a fuel issue....I'm hoping I just busted one injector body or something that won't cost too much....

My injectors will go out tmrw. morning......I'll keep everyone posted when we find the problem!!!

Any thoughts??? Please post up !!!!!!!!!!!!

David
 
Hopefully you will get it all sorted out soon and be back at the track, good luck.
 
:blahblah1::blahblah1::blahblah1:...Just messin with ya man..Glad all your pistons were fine..maybe it will be the injectors and then it will be all fixed again
 
cumminsX said:
Hopefully you will get it all sorted out soon and be back at the track, good luck.
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Thanks man!

I was just TOTALLY relieved that I didn't have any motor damage like I did before!!! I don't think I could handle another build so soon!!!!:bang

Fuel issues seem to be an easier fix!! I hope....

Somebody need to start building a Majorly beefed up aftermarket injector body for these modded trucks.....Or I just wished I could afford a brand new set of the new Stainless Steel bodies from Bosch.
 
fingers are always crossed for the big guy, god knows I dont need mine crunched by the law .

Hey BW dont buy a 6.7 YET!!! LOL
 
Good news David, I was hoping everything looked good. Is Don able to turn your sticks around pretty quick? Look forward to the findings.
Rob
 
Well that's good to hear that your fresh motor isn't the problem! I hope you get if figured out soon. I know your itching to be back in the HP range that you were. With that being said I would be too!!
 
I'm not an expert but i'm guessing your injectors will come back with a clean bill of health. I think you probably have an electronic gremlin that's hurting your performance. When your sticks check out, you ought to make a dyno run while hooked up to a scanner. See if you're getting full load. See what your IAT is reading. See what your map sensor is reading. And then find someone with a lot of good notes to compare with.

Have you inspected both turbine wheels to make sure nothing went through the exhaust side of your S480?
 
Big Blue24 said:
I'm not an expert but i'm guessing your injectors will come back with a clean bill of health. I think you probably have an electronic gremlin that's hurting your performance. When your sticks check out, you ought to make a dyno run while hooked up to a scanner. See if you're getting full load. See what your IAT is reading. See what your map sensor is reading. And then find someone with a lot of good notes to compare with.

Have you inspected both turbine wheels to make sure nothing went through the exhaust side of your S480?
Click to expand...

^good guess^

Injectors don't seem likely with no obvious sypmtoms. I'd go with big blue on this one.
 
Is yours making any strange sounds that you can hear in the exhaust or through the air filter?
 
RAB 38 said:
Is yours making any strange sounds that you can hear in the exhaust or through the air filter?
Click to expand...


Yup!! Not sure about the exhaust except the sputtering at low rpm/boost but I've not heard it outside the truck...

The Air Filter has a wierd little hollow pop in it while idling....


I do here some ticking coming from the engine compartment though..similar to the sound I heard when I had my last injector problem..
My rattle that used to go ahead after boost is made still gets quieter when boost is up but I can still hear a ticking....Even up in the 20+ psi of boost range.....

Any thoughts?
 
Big Blue24 said:
I'm not an expert but i'm guessing your injectors will come back with a clean bill of health. I think you probably have an electronic gremlin that's hurting your performance. When your sticks check out, you ought to make a dyno run while hooked up to a scanner. See if you're getting full load. See what your IAT is reading. See what your map sensor is reading. And then find someone with a lot of good notes to compare with.

Have you inspected both turbine wheels to make sure nothing went through the exhaust side of your S480?
Click to expand...

That will be my next thing is the injectors check out....Electronics :bang

As for the Exhaust on the 480...I haven't checked it...I checked my top turbo when I sent it in to Htt for the fix....
 
Bob Wagner said:
fingers are always crossed for the big guy, god knows I dont need mine crunched by the law .

Hey BW dont buy a 6.7 YET!!! LOL
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Thanks for the support Bob!! :Cheer:


What's up with the 6.7 deal??? I wasn't in the market jsut yet, but thanks for the heads up!! lol
 
Big Swole said:
Yup!! Not sure about the exhaust except the sputtering at low rpm/boost but I've not heard it outside the truck...

The Air Filter has a wierd little hollow pop in it while idling....


I do here some ticking coming from the engine compartment though..similar to the sound I heard when I had my last injector problem..
My rattle that used to go ahead after boost is made still gets quieter when boost is up but I can still hear a ticking....Even up in the 20+ psi of boost range.....

Any thoughts?
Click to expand...

I have a sound coming from mine now it is kind of a thumping sound you can hear through the airfilter and the exhaust. I have higher egts than normal and its not building boost off the line like it was. I am going to check my valve train tomorrow.
 
RAB 38 said:
I have a sound coming from mine now it is kind of a thumping sound you can hear through the airfilter and the exhaust. I have higher egts than normal and its not building boost off the line like it was. I am going to check my valve train tomorrow.
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That sound's like mine as well....The noise and less spoolup.....

Is you smoke even at WOT more than normal..?
 
yes, it does, and it seems real laggy hard to get up on boost. Its wierd, truck idles smooth starts fine(every once and a while seems to crank a little longer than normal), just has this odd sound, smokes more and laggy.
 
onetun said:
Good news David, I was hoping everything looked good. Is Don able to turn your sticks around pretty quick? Look forward to the findings.
Rob
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Not sure about the turn around time...They are so great to me that I don't want to press them about time....They are always SO busy!!!
 
Sorry to hear about your problems. I hope you get them sorted out soon and cheaply.

Do you hear any kind of a chirp noise out the exhaust when idleing?

Did you loose any boost going down the track?

Have you measured the valve lift (measured at the valve), on each of the cylinders?

When doing the compression test, did the pressure come up the same amount on the first piston stroke?

Paul
 
paulb said:
Sorry to hear about your problems. I hope you get them sorted out soon and cheaply.

Do you hear any kind of a chirp noise out the exhaust when idleing?

Did you loose any boost going down the track?

Have you measured the valve lift (measured at the valve), on each of the cylinders?

When doing the compression test, did the pressure come up the same amount on the first piston stroke?

Paul
Click to expand...


Thank you sir!! I do too!!

No chirping noises from the exhaust at all....Runs / Idles pretty dang smooth especially once its warm!! Cold, it sputters and white smokes a bit due to my major decompression...

Lost a little boost during the slower runs but I think that had more to do with my WG cover plate being warped and bleeding off exhast down on top of my 480....Got that fixed and the boost is just about where it was before..62-64 ish...

Never measured valve lift and not really sure how to.......I'd love to learn though and what to look for while I've got it torn down....

The psi came up in fluttering stages as I was watching the gauge while a friend turned it over for me.....It made it up to peak on each cylinder after...I don't know....Maybe 3-4 secs of turning....maybe a bit less.....
Is that normal????

Any help / teaching is always appreciated!!!!!:Cheer:

David
 
Hey guys, I have been having a loss of power at low boost and slightly less power on top of the turbo. there is more smoke present. I checked, rechecked and then checked everything again and found nothing. My truck loped on and off at idle, im was stumped.

Here was my train of thought not building boost and more black smoke are related, so what could cause that,....timing?.....air flow........? gremlins?.......

I seemed to be chasing my tail until i did my data logging at night when is was a nice cool 64 degrees f.

All the power was there, when it was cooler all was well, the 66/16/71 turbo lags something fierce now that summer is hear and to compound that the big sticks aren't getting the air density the need to really get cooking let alone light the turbo quickly. I satisfied myself with that answer after making multiple runs in the evening and the confirmed it again in the middle of the day at 3950ft above sea level., when the power dropped off again.

Does that sound like what was going on??
 
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