I have an 88 tbi 305 im gettin a code 44 o2 lean and the car fluctuates idle speed . I have replaced egr and iac . while driving it has almost no power or throttle response. i think it me fuel pump but i didnt see a pressure test port. ( like tpi) .please give me your ideas thanks!!!:hail:

 

To read the pressure on tbi you would need to splice in a fuel pressure gauge. It should be around 10-12 psi. You might also replace the fuel filter, fuel pump relay, and check your fuses to the pump and injectors.

Could also be tps, or o2 sensors being bad. I would try the filter and pump relay first they are both like 3 bucks.

 

well i do have a scan tool and the tps seems to be normal . good advice on the tps . the fuel filter has been replaced. i havent replaced the o2 i didnt know if that would make a dramatic effect . the relay is also a good idea . thanxs for the suggestions if any one has anymore please feel free to post. ps i have a fuel pressure guage for a tpi schrader valve any suggesions on a fitting to put between the fuel inlet line and the tbi?

 

I went to napa and got a small block with 3 holes in it. Two on the sides and one on top for the gauge. Then get some rubber fuel hose and splice it in.

 

get some carb/fuel injection cleaner for about 5 bucks and try spraying down your TBI unit really good. This fixed the idle problem on my GFs V6 RS, and her V8 RS. If that doesn't fix it it could be an o2 sensor but it is more likely the fuel pump or something in that line reducing the fuel pressure. Ohh yeah and that cleaner stuff can make it hard for you to start the car do to much just do it several times. It also makes the TBI unit look all nice and shiney

 

now do i spray it down while the car is running or when its off? i just added some to my tank because the idle was bumping up/down a little. Also do i need to spray it or pour a little on the injectors themselfs?