Timinv belt replacement

When i did the belt replacement, there were of course the factory stamped marks on the cam gears, but i also had painted marks , that judging from the color, were done at the factory.
I put the belt on using the stamped marks on the cam gears.
I am at an impass, cant figure out what is wrong , i will describe as best and as short as i can.
Starts up just fine, no problems.
Driving , from 3500 to 4000 rpm, it is slow to accelerate .
I am woundering if you guys use those painted marks or the stamped marks , when you install a ne belt.
I have checked timing , it is correct.
It advances as it should , but there is this flat spot,
I dis replace the tps, with little if any positive results, replaced mass airlow , better, but still not perfect.
I did reace the knock sensorz, and harness, have no codes .
Any help is greatly appreciated .
By the way, the painted marks are i think lime 2 teeth off from the stamped cam marks .
I dont know if that is retarded or advanced , but id they are advanced from the stamped marks it would make sence that my obd2 is reading timing retard at those rpms.
Thanks
Ashley

 

On other marquees I've worked on your description would indicate a 1 or 2 tooth retard on the cams. Not familiar with Taco procedure yet, but its worth considering in your evaluation.

 

Well, the question is, did you observe the position of the marks BEFORE you disassembled, and then put it back together the same way....I use my smart phone when it comes to things like this, takes the guesswork out of the picture. You may have one of the cams one notch off which will cause problems like you describe....you may have to take the cover off and recheck the alignment...this is taken directly out of my Chilton repair manual:

set the No. 1 cylinder to TDC of the compression stroke as follows.....

a. Turn the crankshaft pulley and align its groove with the timing mark 0 of the No. 1 timing belt cover

b. Check if the timing marks of the camshaft timing pulleys and the No. 3 timing belt cover are aligned. If not, turn the crankshaft pulley one full revolution and recheck...

It sounds like you may have to recheck the alignment of the belt...bummer...good luck...

 

That was quick, kind of what i have been thinking.
Might pull it apart again, and set it to those marks , see if i net the results i am after.
Truck has good power as long as you are not in that 500 rpm range, which is the happy spot .

 

I did not verify , that when it was at top xead center , the paint marks were the referance.
I have some time this week , and will try the paint marks instead of the other .
I was at top dead center , but i know from other makes i work on , there are variences in assembly, the manuals dont cover.