It doesn't make sense to me but is there any way my shift points could have changed after adding an exhaust to my truck? I know I'm crazy but the truck just doesn't feel the same. 2000 7.3, I just put a magnaflow mufflered 4" turbo back on. Sounds awesome now (quiet compared to the crap that was on it) but my shifting sure feels different.
Thanks,
Brian

 

Exhaust backpressure can theoretically effect shifting - the Exhaust Back Pressure sensor would make a good "load meter". My tuning friend hasn't found any link to the EBP and the shifts, but the EBP sensor signal is one of those 7.3L mysteries that hasn't been completely sussed out yet. While it may not have a direct link in tuning, I don't know if it biases other sensor readings. The only diagram I've seen is where the signal goes into a big square marked PCM.

I can say a lot of people have clogged EBP sensors and they clean or replace them - to find their truck behaving differently in one way or another after the work is done.

One other possibility is you're "permagrinning" with your right foot more often, to hear the new sound your engine makes and feel the performance. That effects shifts for sure.

 

I don't know what's going on but something is definitely different. The early shifts you don't even notice them happening, then 3-4 feels like it's holding on a bit and shifts at 2500ish. I haven't paid attention to the RPMs much but It just feels off. The other thing that happened today was two different times, I let off the accerator just a bit right after it shifted gears and it downshifted real fast then upshifted. The transmission was rebuilt about 30k ago so I don't think it's the trans. My only concern is that we are taking the toy hauler out Friday about 120 miles away.
Thanks for the reply.
Brian

 

Sounds like the trans to me. Try and see if there's any codes. I put that exhaust on mine years back and didn't have any problems at all.

 

Is it possible some wiring was disturbed during the exhaust install?

 

While I was doing the exhaust, I removed a wiring connector from the passenger side strut tower maybe? It was held by 3 10 or 11mm nuts. I just removed the nuts and moved it to the side to get better access to the DP. Another thing was while doing it, I found oil on the backside of engine (which I made a post about). I then saw another post about leaks from the valley and looked. I had oil pooled in the valley so I tried to clean that up as good as I could. I removed one sensor (I believe on top of driver's valve cover). The plug was quite oily so I sprayed some CRC electrical parts cleaner on both sides and reconnected it. I then sprayed some simple green in the valley (was hard to only get in valley with all wiring so there was overspray I'm sure). Then I sprayed the valley out with a hose. That's everything since the exhaust. I think that's pretty much everything that has happened since doing the exhaust.
Thanks,
Brian

 

There it is... you altered your Injector Control Pressure readings. That would certainly mess with your shift points, as well as how the engine runs. You may be a candidate for a new ICP sensor.

Try unplugging the ICP sensor and leave it off (you'll get a SES light). Start it up and go for a drive. What does it do?

 

Is that the plug I undid on the valve cover?
Brian

 

If there is oil in the connector of the ICP you need a new ICP, oil is pushing past the sensor, sometimes you have to replace the connector as well.

 

Ok.. I am going to pick my toy hauler on lunch now I think. Is that sensor something I can leave unplugged to go on my trip this weekend? Need to do it first? I can see if I can find one.
Thanks, I will unplug this before I get the trailer! I should know instantly.
Brian

 

Also, I found a standard motors ICP102 on amazon for 111. I can probably have it here tomorrow if it will work.
Is this one acceptable?
Brian

 

I think you will find that most here are going to suggest you only use OEM for this particular part. Lots of threads about engines doing strange things and being shut off by rf interference using after market ICP sensors.

Injection Control Pressure ICP Sensor 97-03 - Riffraff Diesel Performance

Clay can usually get things to you pretty fast

 

Ok, 206 retail price on that. It really sucks not working parts at a dealership anymore LOL. I have a bodyshop friend talking to her ford source so I should find out in a bit. Thanks for that info, looks like some aftermarket parts are OK, others are not. I'm just trying to figure out this diesel world. It's been eye opening so far! I've been on many forums for other vehicles, this one is up there as far as helpfulness.
Brian

 

I found this doing a quick search. Just one example of ICP issues.

https://www.ford-trucks.com/forums/1...rence-rfi.html

 

Did you unplug it first and take it for a ride? That will tell you if that is the problem before you order a new one. I guess if its got oil in it you need a new one anyway but that still mitt not be the problem.