7.3L Miss at Mid-RPM

Black 02

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What is the scoop?

No response from Joey. Pretty frustrating.

I've been driving with the stock pump and it's been running pretty well. Very subtle surge at mid-rpm (could be trial tunes), but otherwise pretty good.

I still have the heavy smoke on startup and also the hazing at idle. There's also the random miss at idle when warmed up. Since it did this in the previous engine, I've been wondering if there is something not quite right with the injectors.

I've been told by several that some of that can be worn or poor tolerances in my injectors. I decided to pull them out yesterday to send in for analysis. Pulled the #6 injector and heard a subtle chugging noise. Look over and see my degas bottle coolant level going down. FML.

So, I'm guessing when I pulled the injector, an injector cup moved. I don't know why else the coolant level would start dropping. I pressurized the coolant system, but it won't hold pressure and it starts filling the cylinder with coolant. I can't removed the cup by hand, but I can't think of any other reason why this would happen.

I swear it could be raining pu$$y and I'd get hit by a giant dick.
 

Layson

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Hopefully it is just an injector cup. But I have never heard of that happening when you pull an injector......


Any of your friends have some injectors you could borrow....LOL. Some that you know are good. LOL

Hell I bet stock injectors would work just fine...LOL Someone has to have some laying around you could throw in.


Too bad about Joey. I would keep ****ing texting him. Send him pictures of stuff...LOL
 

Black 02

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Hopefully it is just an injector cup. But I have never heard of that happening when you pull an injector......


Any of your friends have some injectors you could borrow....LOL. Some that you know are good. LOL

Hell I bet stock injectors would work just fine...LOL Someone has to have some laying around you could throw in.


Too bad about Joey. I would keep ****ing texting him. Send him pictures of stuff...LOL

I don't know what else it could be. If it was a head gasket, it should have been doing this for awhile now. It takes very little pressure and pushes a lot of liquid into the cylinder when pressurizing the coolant system. It wasn't doing it before the injectors were removed because the engine would have been 100% hydrolocked.
 
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Swaan

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It's your inj cup. You need to replace it with a new one.
Old one could of just came loose or maybe even cracked, but I'm betting it just came loose.
 

Black 02

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I just the injectors back after having them gone through. Just got them installed Saturday. After the air was out of the system, the truck runs as smooth as it ever has with your trial tune. Cruising, idling, starting cold… Everything is top notch. Just a slight haze of exhaust.

On a side note, I have a concern that I may have a blown HG. I sure hope not, but I’ve heard it’s somewhat rare on a 7.3L. I’ll try changing the degas bottle cap first, but it’s not real old. Anyway, after getting 100 miles or so on the truck and it was fully warmed up for quite a while, I got on it to see how it ran. The tune is just a trial tune from Swamps, so it’s not putting max fuel into the cylinder either. Anyway, after getting on it and building about just a little over 45 pounds of boost, it puked less than a coffee cup of antifreeze out of the tiny hole under the degas cap. I drove about 5 more miles and parked at my house. That’s when I noticed the antifreeze. It actually started to do this a few weeks ago before I pulled the injectors. Just a small amount of antifreeze on the outside of the degas bottle near the cap. When changing the injectors, I found a leaky injector cup and replaced them all. Cleaning the cups holes extremely well. Figured that was the problem of why it was doing it. I changed all 8 injector cups and used the proper install tool with the correct Loctite. I can’t fathom it still being an injector cup because I cleaned them extremely well.

The truck has just a slight greyish haze of exhaust and the oil doesn’t seem to have any water in it.

It fires up cold really great, idles super smooth, and cruises on the freeway awesome now. I'm really happy except for this damn antifreeze leak.

Engine has cometic head gaskets with ARP studs.

I sure hope it's just the degas cap.

If I didn't have bad luck, I wouldn't have any at all.
 

Layson

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Who went through the Full Force Injectors? Did they find anything?
 

Black 02

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Who went through the Full Force Injectors? Did they find anything?

PIS went through them. They found some scarring on some components and some of the flows at different pulse widths weren't the same across the board minus some expected error. The scatter was higher then you'd like to see. They repaired the worn parts and got the flows a lot more consistent.

It wasn't cheap, but they took good care of me. I'd only run PIS or Swamp's injectors if I was gonna do it over again.
 

superpsd

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Glad you got it sorted out. Although Tim is slightly arrogant when he posts he does seem to do a great job. Not to often do you hear anyone complain about poor worsmanship coming from his shop. He may cost a bit more but after reading his post. He is one of the few that does not compromise a product using second rate parts or bandaid fixes to save a buck.
 
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Black 02

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Glad you got it sorted out. Although Tim is slightly arrogant when he posts he does seem to do a great job. Not to often do you hear anyone complain about poor worsmanship coming from his shop. He may cost a bit more but after reading his post. He is one of the few that does not compromise a product using second rate parts or bandaid fixes to save a buck.

I wasn't going to say anything, but Tim reached out to me in a PM and asked if he could help in any way. Never met him, don't know him, never bought anything from him in the past, but still offered to help.

Golfer at Swamps is the same. Except, I have bought stuff from them for my truck. Always willing to help and usually has the solution to the problem or knows what the problem is.

I'd buy either one of them dinner and a several rounds of beers if I ever get the chance.

I'm just worried about this damn antifreeze issue now. I'm so excited to drive my truck when it's running as smooth as it is. Nice weather and tons of power makes me happy!!! :redspotdance:
 

mandkole

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Damn..

Throw a pressure tester cap on the bottle and cross your fingers. Don't you need to season those gaskets a little and retorque before putting the pressure to them? How many miles on the gaskets?

Great to hear the injectors cleaned it up.
 

Black 02

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Damn..

Throw a pressure tester cap on the bottle and cross your fingers. Don't you need to season those gaskets a little and retorque before putting the pressure to them? How many miles on the gaskets?

Great to hear the injectors cleaned it up.

There's about 4000 miles on the engine since it was built. The engine builder told me I didn't need to retorque them. He said they were good once he torqued them originally. I'm not sure. Hope he didn't lead me astray.

I haven't completely put the wood to it yet. I've been driving on trial tunes trying to figure that miss out. I've pushed 45 psi before, but that's about it.

This morning I went to check the oil and the coolant. Removed the cap and there was still a good amount of pressure on the cap even after sitting over night. Wouldn't a head gasket bleed off over night??? There wasn't any white smoke or anything on the cold start.
 

TyCorr

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I agree with your advice OP about injectors. Ive ran all three you mentioned and my findings are the same. Swamps or PIS.
 

907DAVE

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Fwiw, my Cometics lasted about one day before they blew using H-11's. The fire rings are still going strong after a couple years.

Sent from my SM-G925I using Tapatalk
 

golfer

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yeah...something changed in the Cometic world about 8 years ago....

which is exactly when we quit dicking with them...

FR's and done.
 

TyCorr

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Yea. I was thinking about pulling my heads to seecwhat was going on while the truck is apart but i dont have any faith in a gasket and stud holding after that. And i dont want to fr my stock motor.
 

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