Hey guys I'm having some problems with my 02 7.3. It has 170k with a 4 inch straight pipe, intake, and ts6 with canned tunes. The truck has trouble building boost under 2,000 rpms and it has to downshift for even the slightest incline. Now once it down shifts my gauge shows about 24 psi wot but it doesn't feel like it. Truck is a dog. Any ideas? Please help

 

Got any smoke? What color?

First thought is loosing boost to leaking up pipes, look for soot on those pipes and the firewall. Tho if it holds 24 psi that's a good sign.

Other thought is clogged exhaust back pressure sensor. Especially if your MPGs are down. It can be removed and gently cleaned, and the tube too.

Got a CEL and a way to read it?

 

No check engine light and just a little blueish smoke when it's super cold out. Only for a second. I have noticed that if my windows are down when I first start it and take off that the turbo has an odd sound for a second or 2 then goes back to its normal sound. But yes my mpgs are horrible. Thanks for the link I'll give that a try!

 

How are you reading boost? Gauge or OBDII port? If you are reading it off the OBDII port with a scan gauge, are you looking at MAP or boost? If it's MAP, you must subtract the pressure of your altitude (about 14 PSI in WV)... leaving you with 10 PSI boost. This sounds like it could be an Exhaust Back Pressure sensor issue, an exhaust leak, or a boost leak if the MAP scenario above is true.


The low power sounds like an Injector Control Pressure issue, what happens if you unplug the ICP connector and drive it?

 

Thanks for the reply, I have a boost gauge. I will unplug the icp on the way home from work and report my findings.

 

24 PSI boost? A stock engine with everything at 100%, good breathing, and good tunes can pop 30 PSI boost. We haven't yet ruled out some form of exhaust/intake leak.

 

Alright while at work I unplugged my icp while it was idling and it increased idle for a few seconds then it went back to the way it was idling. I'll drive home with it like this and let you know. Think I could do the same with my ebpv. Where should I unplug it?

 

Ok guys so I drove the truck with the icp unplugged and it definitely built up boost faster at lower rpms. It still doesn't seem to have the proper power so my next step will be a boost test and unplugging the ebpv. Thanks for the help guys, is it safe to say I need to replace the icp?

 

Not necessarily - the ICP is bumped when the sensor isn't there. I thought it was prudent to see if we should at least take a closer look or to move on. With your results, I am now curious what your IPR does when your foot calls out for fuel. For that, as well as other questions as to what's going on with Boost and EBP, it would be nice if you had a scan tool/gauge available.

 

I do. Let me know what I need to check while at idle or etc. and I can let you know what the readings are.

 

Very cool.

What is most helpful is a full spread under real-world driving, including a WOT run from stop for at least 10 seconds (uphill is best). Recording the following PIDs is very helpful, but omit the Mass Fuel Desired, and swap Transmission Fluid Temperature for Torque Converter Slip (max 1000 RPM). The upper and lower limits on the PIDs are for the sake of easy graphing while monitoring and on playback.



You can then share the file after recording.

 

The scanner belongs to my work so I'll have to figure out how to get it to record but I'm sure they'll let me take it home for the evening tomorrow. I'll try to see if I can get it to record the file. If not I'll just try to snap a few pictures of the screen.

 

Also should I have the icp plugged back in for that?

 

Yes, you'll want everything set to stock configuration.

 

Chip also?