I’m new here and I have some questions.

[cowboycurtis]

[attachment=6082]I bought a 2007 Peterbilt with an ISX450 and 990,000 miles about a year ago. It has the EGR removed. The check engine light is always on. Also the manifold pressure gauge on the dash runs at about 22psi for max pressure. What does a typical ISX450 run for manifold pressure?

This truck seems to be a little short on power. I have 2 2003 Freightliners with 12.7 Detroit’s that will walk away from the Peterbilt.

What should I be looking for and what are my options?

[Brock]

Does it have the original turbo or aftermarket?

[cowboycurtis]

(01-13-2020 )Brock Wrote:  Does it have the original turbo or aftermarket?

I don’t know. I’ll get a picture of it and look through the maintenance book that came with the truck.

[Brock]

Does it have a air actuator on it?

[cowboycurtis]

(01-13-2020 )Brock Wrote:  Does it have a air actuator on it?

Yes and it was just replaced last week

[jakebank]

I have one with the same CPL, 500/1650 tune on it and it gives me 34-35 max boost in certain conditions but typically 30 psi boost under full load. My EGR is still intact. When Jake braking at 1800 rpm I get 26-28 psi on the boost gauge. Mine has a reman turbo (previous owner) and I recently had to replace the actuator. Hopefully that helps you some.

[Rawze]

(01-13-2020 )cowboycurtis Wrote:  I bought a 2007 Peterbilt with an ISX450 and 990,000 miles about a year ago. It has the EGR removed. The check engine light is always on. Also the manifold pressure gauge on the dash runs at about 22psi for max pressure. What does a typical ISX450 run for manifold pressure?

This truck seems to be a little short on power. I have 2 2003 Freightliners with 12.7 Detroit’s that will walk away from the Peterbilt.

What should I be looking for and what are my options?

If the egr was removed and someone put in a program for that .. then its 99% most likely a bad program.. you chances of someone having doen it rught are very very slim..

It is a CM870 engine, so it is also possible someone just unplugged the egr valve and let it derate (boost derate)... some people drove them around like that, but it is really hard on the turbo and EGT's go through the roof, shortening the life of the turbo by 1/3.

- Either case, if it is to be run without the egr on it, it will need re-programming for it to operate correctly.

[Rawze]

(01-13-2020 )jakebank Wrote:  I have one with the same CPL, 500/1650 tune on it and it gives me 34-35 max boost in certain conditions but typically 30 psi boost under full load. My EGR is still intact. When Jake braking at 1800 rpm I get 26-28 psi on the boost gauge. Mine has a reman turbo (previous owner) and I recently had to replace the actuator. Hopefully that helps you some.

30 psi under full load? -- YOUR BOOST LEVELS ARE TOO LOW!!!--- SOMETHING IS WRONG WITH YOUR TRUCK!!!


The CM870, when running properly and there are no derates, should peak at about 36-37 psi boost under full engine load and foot to the floor AND STAY THERE. - It should also be consistent, and not be sometimes high or low.

- You need to find out what is wrong with your truck, or suffer shortened turbo and/or engine life!.

[cowboycurtis]

Ok, so I’ve really been paying attention yesterday and today. So here’s what I got: I did 425 miles yesterday. Loaded at 70,000 one way and empty at 28,000 back home on a windy day and averaged 4.9 mpg. Today I did pretty much the same thing with less wind and got 5.2 mpg. The manifold pressure gets to 22psi and stays there climbing the hills. On flat ground with the motor not pulling hard, engine rpm is 1500 at 70mph with 12-15 psi of boost.

If computer needs reflashed how do I even start that process? If it need reflashed shouldn’t a guy jump up the power as well? Go to 500 or even 565hp? Looking for any help I can get here. I got some more pics of my setup.