I just finished installing a remanned 3.0 long block with new injectors, knock sensor wire, fuel filter, plugs, distributor,wires, rotor/cap and a few other parts. My problem is that the truck starts and idles great, but as soon as I give it some throttle and the tach gets to about 1300-1500 rpm it gets real rough. Almost like a miss, but after that point the motor takes off and sounds great again. Also I took it for a test drive and it just doesn't have any kind of acceleration or power. It took forever for it to hit 40 mph and I could tell it was struggling. My timing is set, I'm not sure what else to look at. Any help would be greatly appreciated.

 

valve adjustments, vacuum leaks, throttle position sensor, air flow meter

what procedure was used to set the timing?

 

According to the book set the timing at 0 and checked with a timing light. Also sprayed the vacuum lines with carb cleaner and engine did not pick up rpm's. I haven't thought about the tps or valve adjustments.

 

You had the jumper in the diagnostic connector (and engine rpm's dropped when the jumper was inserted...) while adjusting the timing?

 

That would be a negative. I am not to sure on how to go about this. Where to put the jumper and what to look for so I will do a search first and see what I find. Thanks

 

Under the hood, behind the battery is a fuse panel. attached to the side of that panel should be the diagnostic plug. If you lift the lid on that plug, there should be a diagram of which terminals are what. To get the ECU into the proper mode for setting the timing and reading codes you'll put a small jumper between the TE1 and E1 terminals.
If the engine is running when you insert the jumper, the idle should drop slightly: this is when you would check and set your timing.
If the engine is not running when you insert the jumper, you can turn the key to the 'On' position- don't start it- and the check engine light will flash any stored trouble codes at you.

 

I will try that tomorrow. I sure do appreciate the help in clearing this up. I will give an update once I get it straight. Thanks

 

10 degrees Before top dead center is your base timing with jumper installed.

 

Tried looking at everything we could think of so we took it to the local shop and put it on the computer. Only code shown was the speed sensor at the transmission. Gonna try that if there are any other ideas let me know. Appreciate the help so far.

 

Sounds a lot like the valve timing or distributor is off a tooth...

 

Timing is dead on, triple checked. Talked to a mechanic at the dealership and he said it sounds like the pulsation damper is bad. Any thoughts, about to give up and bring it to the shop.

 

As soon as you put in the jumper, the idle should change. If nothing happened that means the TPS is bad.

I had a bad TPS before and just adjust it to about 24deg. then adjust it down just to pass smog.

 

Foubd out what the problem was, the fuel pressure regulator was bad. Replaced the fuel damper and it still ran rough, clamped off the fuel return off the top of the regulator with pliers and the truck ran like a top.