my 1996 tacoma har a very weak heater what can I do to fix it?

If you are saying what I think you are saying you can try flushing cooling system with Prestone Super Cooling System Flush.

system has been flushed , has new water pump, thermostat, radiator,heater core, and system has been burped still no heat.

How is the A/C blowing ? Maybe the blend door in the heater box that opens and closes when there is a call for heat or A/C is not working pr

Working properly maybe stick half way between heat and A/C.

And when you say weak do you mean not blowing out that fast or blowing out good but still little heat.

Check the heater control valve.

have also checked heater control valve it is working. the blower fan is putting out good. just doesn't heat good . for some reason the temperature of the heater hoses is about 20 to 30 degrees different.

What heater hoses are you referring to when you say there is a 20 to 30 degrees difference the hose going into heater core and the one coming out or the hose before and after the heater control valve ?

Yes it's the hoses going in and coming out of the heater core.

Sounds like the heater core is clogged or partially clogged. Since you already tried the only thing that might have helped you a radiator and cooling system flush the only thing left is to replace heater core. The only recommendation I can give you is to try using Prestone Super Radiator and cooling system flush that is if that is not what you used to flush system first time.

It was flushed at a radiator shop and has a new heater core also

If one hose going into heater core is hotter then the other one coming out it maybe be a new heater core but it is clogged. I have seen many so called new parts be bad.

A question for you did you have this problem before doing all that you had done to your vehicle ? Do you trust the shop that you had the work done at saying they replaced the heater core ?

Yes that's why we have did all this work to it. yes they are a very trustworthy and I've also took the hoses off of the heater core and hooked the water hose to the heater core to check the flow it has plenty of water flow.

You can also run water through a clogged radiator with out the hoses on and you will get good water flow.

What is clogged up is the small passages that the anti freeze flows through in the heater core.