P1688 no CEL

[Marcus2000monster]

Well we all know what this code means. I have been fiddling around under the hood a lot lately and I wonder if I bumped something that could cause the code? Truck still runs ok but seems like it got a bit louder as far as the typical knocking noise. Is they’re any other symptoms that show with this code? I honestly hope I have to do a vp because that could be cuasing a few small issues of been having for a while....

[Mopar1973Man]

Reset all error codes. Then go for about 10 to 15 mile drive see if it returns. If it does there are issues with the PSG on the VP44. 

 

 

[Marcus2000monster]

3 hours ago, Mopar1973Man said:

Reset all error codes. Then go for about 10 to 15 mile drive see if it returns. If it does there are issues with the PSG on the VP44. 

 

 

I cleared it out but havnt not drove it yet. 

[Leaky88]

My turn.

 

Got same code today after 2200 trip last weekend.  

Cleared, drove 15 mi and it’s back. Please define “issues with PSG on VP44”.

 

Not sure I really want to know what PSG since it’s used in the same sentence as VP44.

I can see the TACH taking minute dips and it sounds like a cylinder miss does on a GASSER for lack of better description. Please listen to attached.

 

 

 

Thanks Leaky

New Recording.m4a

[dripley]

The psg is the computer on the VP.

[Leaky88]

Thanks.

So I might as well ask now.

What’s involved in changing the VP 44 out. Lessons learned etc.  

Thanks

 

[dripley]

It is not that hard to do. Mike has an article on it, so does Blue Chip diesel. BC is the one I used since it was pre moparman. I read the instructions several times before I did it and kept them handy while doing it. An extra pair off hands is handy plus it keeps from drinking all the beer yourself. My son and I did my first one in 4.5 hours. Did the next one my self in about the same time. I dont get in hurry when doing a lot of projects unless it is an emergency.

 

It would be good to see what others might say about the problem before completely condemning it. 

[SilverMoose]

4 hours ago, Leaky88 said:

Thanks.

So I might as well ask now.

What’s involved in changing the VP 44 out. Lessons learned etc.  

Thanks

 

Like @dripley said, don't jump to conclusions but replacing the vp44 is not that difficult. I did mine about 6-8 months ago.  Mike's articles are all you need to do it. 

 

L8tr

D

[Mopar1973Man]

This should help out. I've got it down to a science I can typically change them out now in about 1.5 hours. Even though the labor book calls for 4 hours. 

[Leaky88]

Thanks. 

It’s always good to know what “might” be in store for me. 

The VP44 on my truck is a remanufactured one. The truck still had

an OEM Carter Fuel pump mounted on the engine when I bought it which might account for it having remanufactured one.  First thing I did was install a FASS pump and replumb it. 

The only other code I’ve received is a P1291.  My truck throws this when the relays are disconnected during warm weather.  

 

Just thankful this did not happen last weekend on trip to WY and back.

 

The only about today was a heavy rain but I drove through rain last weekend. 

 

I certainly don't want to condemn the VP44 given the cost of replacement if there is something else I’m not seeing that could be causing the problem.  I’ll keep looking.

 

Leaky