Just for an update the i put the 703 injectors in and it does seem to have better throttle response and the hissing went away, but no better at idle so that wasn't the problem. I was thinking it might be the 02 sensor which i did replace with a new bosch around 5,000 miles ago. I unplugged the 02 sensor and if anything it idled better without it. It will idle perfectly for a few seconds, then stumble for a few seconds back and forth and I can't figure out why???

 

You may have a slow reacting oxygen sensor or the oxygen sensor heater relay may not be working well.

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Have you sprayed for vacuum leaks using throttle body cleaner?
Checked the integrity of the hose from the throttle body to MAP sensor?
Made sure your CCV hoses and orifice in the rear valve cover grommet are clear?

 

ya i tested for vacuum leaks the hose looks good from map sensor to TB. I also cleaned all the engine grounds. It's driving me crazy because it will idle absolutely perfect for 10 seconds after I start it and then it seems like something turns off and the engine starts to stumble and it's very random sometimes it's worse than normal and stalls, sometimes it will go back to idling perfectly, but nothing has helped????????? It might be something electrical but I don't know where to look

 

The CCV hose from the rear of the valve cover has a white plastic orifice in it. If it's carboned up along with the tube, idle quality can be affected. Check it out.

Have you ever cleaned your throttle body and IAC?

 

yes i cleaned my TB and IAC. i checked the ccv hose and it's good. How much should the idle drop when you put it in reverse or drive? mine drops probably 3-400 rpms

 

Should not idle at 300 to 400 RPM in gear. Did you check the CCV tube and orifice?