2007 International 4300 Durastar no power on freeway

Mekanic...oh wow! Yea, I thought those numbers seemed a bit high. What I did was drill a hole in the exhaust right before the muffler and tapped a 0-15 PSI (not PSIG) pressure gauge into it. I did not see an o2 sensor or EBP sensor between the muffler and the turbo outlet, which is why I had to machine my own port. The reason I did that is because the live data I was getting from my scanner regarding exhaust back pressure did not make any sense. Barometric pressure scanned just above 14, and we are at sea level so that's about right.

And yes, this is me measuring after the turbo, just before the muffler.

I know I said I was going to do some tests and post data around noon but I came into work late today so I could look at a vehicle. I'm going to inspect the parts inside the fuel filter housing now. Unfortunately I probably won't get to making a hose that reaches from the fuel pressure test port at the rail until tomorrow. I ordered the muffler already, will be getting it in tomorrow morning.

Thanks again! How can I repay you? No, I'm serious...I've been given such great info here, and I want to show my appreciation. Post again tomorrow.

mekanik said:

Monte
Below is a breakdown of the fuel filter. #6 is the orifice/regulator assy. It is notorious for getting debris on the seat and a 5 or 10 psi drop in pressure is a substantial loss in power you a gauge will still read 50-55 psi when not running under load.
The transfer pump has three valves that can wear and not seal enough to cause a drop in fuel pressure and a power loss. Driving it with a gauge installed will tell you for sure if they are good or not.
Also if the high pressure pump is wearing out and cant deliver the desired ICP then the power will not be there.

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Hi Mekanik...I opened up my fuel filter housing and noticed some gunk in the bottom...I have driven it less than 200 miles(and that's strictly for diagnostic purposes) since I replaced the fuel filter and cleaned the housing. Not sure how that stuff got in there.

Also, I'm not sure how to remove that #6 part...does it just pull up? ...or is there some trick to it...

BTW I observed an interesting anomaly just now...I left my diagnostic scanner plugged into the OBD port overnight by accident, so I decided to put the cap back on the fuel filter housing to make sure it still would start(not sure if the scanner turns on auxiliary systems on the can bus while it's plugged in and I know those batteries are pretty much garbage once they go dead). Fortunately it started right up, WHEW! I decided to go check the pressure gauge that is still sitting in the exhaust pipe right before the muffler and it was reading 3.5 PSI. This is reading right after startup with a cold engine. Yesterday with a warm engine it was reading just under 1 PSI. Thought it was worth noting.

[EDIT] 15 min later engine temp up to 155(as indicated on instrument cluster gauge) pressure just before muffler now at 4 PSI.

Okay, sorry for so many posts...was trying to order a new muffler, and while taking measurements, through the rust I could read a stamp...."CATALYST". Looks like it is a catalyst muffler. That explains a lot. Now I'm almost certain that's the culprit. As tempted as I am to cut the thing off and replace with a standard muffler I think I should just bite the bullet and buy another catalyst muffler. To test, can I cut the thing off and see if it runs right?

The orifice in the filter housing takes a 7mm allen wrench to remove it. The grit in the bottom of the housing will go through the orifice into the fuel inlet and through the strainer and then through the transfer pump and back into the filter housing going around continuously until enough builds up in the orifice to cause a power loss.
With the orifice out some brake clean and a blow gun will usually get the orifice clean.
You need to get all that grit out of the housing. Take the inlet line off and with the orifice removed flush the filter housing out.


Catalyst mufflers are very expensive! Can you remove the muffler and take it for a test drive without it?

That's the plan. I figure there are no sensors after the turbo outlet, so about the only thing that will happen if I remove the catalyzing muffler is a slight drop in backpressure. I'm 90% certain that it should still function correctly without it. Hopefully the engine doesn't rely on a little bit of backpressure to seat the exhaust valves correctly. But yea, here in a couple hours I'm gonna cut that thing off and take her for a spin.

I will take care of that gunk in the fuel filter housing today for sure, but I want to do this exhaust test first. RWS group want's $2600 for that catalyzing muffler, but I have the International part number, and found one new on eBay for $600. I'm going to jump on that as soon as accounting gives me the approval.

Thanks again Mekanic. I think I see a light at the end of the tunnel! No, wait, that's just a mirror reflecting light back from the entrance behind me...

To all you folks experiencing weird turbo issues on your 06-07 4300 series with a DT466, the issue turned out to be a plugged cat. I did not know there was a catalytic converter INSIDE the muffler. It wasn't until I drilled a hole right before the muffler and inserted a 0-15 PSI pressure gauge and found a high PSI reading that I started to investigate a restriction at the muffler. It wasn't until I saw(through the rust) a stamp on the muffler reading "catalyst" that I realized the muffler may be more than just a muffler. While the PSI just before the catalyzing muffler should have been reading just less than 1 PSI at 2000 RPM not under load I was reading 20 PSI. Cut that b#%ch out and BOOM! Power restored. I hope the experience from this two month long nightmare that I have finally awoken from helps someone avoid a time consuming and costly effort.

Thanks again Mekanic and all of you others that gave me advice. BTW, the International part number for the cat muffler is 3612612C1. I found one on eBay for $600, less than 25% of what the dealership was asking for the same part. Good luck all, and happy mechanicing!!!

materthegreater said:

Why not just take the muffler off and take it for a test drive. I think mine is governed at 2600 rpm or so but I guess I haven't tried flooring it in neutral to find out.

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That's actually exactly what I did. Only I was getting weird back pressure readings from my live data so I opted to drill a hole just before the muffler and tap a mechanical pressure gauge in. I was reading 20 PSI at 2000 RPS under no load in neutral, which is more than 10x what it should have been. Then I was about to cut off the muffler to take it for a spin and I saw the word "CATALYST" stamped onto the side of the muffler. Found out there was a catalytic converter INSIDE the d$#%ed muffler. Neither of the two shops had even heard of that so I guess it's somewhat of a rarity. And the dealership neglected to mention it after charging me an outrageous fee for a diagnostic.

Long story short, catalyst muffler removed, truck ran like a dream.

TorchHypnosis said:

Okay everyone. Got the truck back from RWC group truck dealership in Tacoma WA, can't say I'm impressed,

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Oh’ boy. I’m sorry
Try to avoid that going forward.