Any lifelong Mopar Techs that remember the OBD1? ...Fuel Sync Question..
Swapped a 5.2 from another truck that was getting 15mpg. Did the timing chain and Dist because one of the tabs broke while disassembling. I marked everything exactly & it runs well EXCEPT MILEAGE!! I discovered this Fuel Sync procedure using a meter. I see there is a procedure using a good scan tool, but not sure if there is something for OBD1....
So for you guys that have done this is there an option for an OBD1 truck and is the meter procedure as accurate as the scan tool... Or any other suggestions?

Im not a lifelong tech- but- only current way i know of to do fuel sync in snap on "mt2500 red brick" with the appropriate year insert. maybe the solus does it too? lots of money though....

Just read this post and I’m interested in this procedure too, I have the Solus Ultra Snapon scanner box, didn’t get the manual. My Ram van went from 15 down to 12 after going back thru the trans.? thinking about fuel trim thing, but not knowing about this fuel sync thing. I hope someone comes on with answers to your question.

What motor are you talking about? Pre 92/93(depending on what motor) are throttle body injection. You can set the fuel sync on the magnum motors like this:
TDC #1 ON THE COMPRESSION STROKE Set the distributor like this...

Doesn't that procedure just get you in the ballpark, just enough to get it running? That was my impression about that procedure. Yes it's a Magnum engine 92 to the exact. I just thought there was a more accurate way of doing it. Like some of said if it was OBD2 you could actually do it with an expensive Snap-On scanner. With it being OBD1 what's the alternative?

Well this procedure is in the service manual for a 96. I believe the later ones you can use a scanner that will take into consideration the wear such as timing chain and distributor gear wear to be accurate. I have not heard of any other explanation.

I don't see how it could matter much. Cam signal is just an on/off deal once per distributor rotation. Don't see how injectors being out of phase with it by a degree or two could make much difference. Lots of older v8 fuel injection systems were batch fired one bank all at the same time.

In your deal the motor went from one veh to another, diff trans, tires, etc. Lots of variables other than just fuel sync.

I wasn't aware that older systems functioned that way...I'm just trying to narrow it down.. I'm just angry because same motor same transmission and a lighter vehicle by about #800 to a thousand pounds I was hoping not to lose mileage with upcoming gas prices!

This is why i asked for the year. If it's a magnum you need to set the fuel sync, If it was a LA there is no setting it because it's throttle body injection.

Is the rear end ratio the same in both trucks?

I just did my 01 5.9, I set distributor close to where it showed in book then used the Snapon scanner to sync it (it did it on its own) seems to run better. I just overhauled the trans and Van went from 15-16 to 12 mpg (4.10 rear) we’ll see how it does now. Also I changed nothing on the engine other than trans. One other thing I had to adjust the cable to the pressure lever (shifting hard)

Yes

That's crazy it lost that by just a trans rebuild?

92 RC to a 93 Dakota same trans and gear... Both Magnum motors

Well I might have found the problem and it could be yours too, crank sensor. I removed it during trans in and out, I did have trouble with this sensor before with losing power. I’ll go buy a new one from Dodge, the auto parts ones are junk from what I hear.