I just did a basic tune up on my V10....spark plugs (badly needed) air filter & oil change...basic. The performance has improved a lot.......however, it still seems to lack the "punch" that it used to have. Zero signs of any compression/valve issues on the plugs. To me, it feels like the timing is off, but I'm under the impression that there is no adjustment for ignition timing on these engines. Is this true? My other thought is that there's a vacuum leak somewhere..........once it gets rolling it has plenty of power, but it takes a lot longer to get into the power band....just kind of boggy from a standing start. Any ideas? Thanks!

 

There is no timing adjustment as it uses a DIS that is controlled by the computer.

The timing chain however does wear/stretch over time. Depending on the miles you have on it, it might need replacing.

A vacuum leak is a possibility, but that ususally manifests itself in other ways as well (noise at shut-off, AC vent switching, etc).




Also, I don't know if you ended up changing plug wires or not, but make sure this problem isn't afflicting you: http://dodgeram.info/tsb/1998/18-16-98.htm

 

Just rolled to 130K. No wire change. Hmmmmmm, I sure don't want to mess with a timing chain change if it's not NEEDED for sure......kind of a big job.

Is there any standard vacuum test points on these engines? Ie: Gauge here should be Xlbs. gauge there Xlbs etc...?