ok mayby not but il be forever in dept.....
so ive got this 305tbi ,start it up and it purrs beautiful for about 5mins then its like a switch goes on and it starts missing running rough! turn it off and let it cool and it usualy comes right? so annoying! seems like it cant keep up with all the gas its getting. like its choking itself? seem like gas is pouring in!
could it be a sensor? which one would do that? i tried the paperclip trick to chek the codes but light wont even come up? am i doing it right?
anyone out there can help? like i said it just switches from beautiful to crap like its a switch?p.s im in new zealand so know one wants to know about it....... people telling me to rip the efi out and go to carb. please help a brutha out.....

 

Is the check engine lite lit?

 

if its not flashing a 12 then either your doing it wrong or the diaognostic system is not working. what yr?

 

Im working on an 85 T/A right now thats was doing about the same as you are explaining, but this one has a tuned-port 383. I checked everything out in the datastream using my diagnostic tool and found erratic MAP sensor readings..replaced the MAP sensor and it cleared up for a while but then it started acting up again..now im running through the wiring to see if there are any problems in that area..but try a MAP sensor just for grins and see if that helps

 

Most likely there is a sensor problem. When the engine is cold it runs on open loop and most sensors are ignored. When the engine is warm it swiches to closed loop operation, and all sensors are recognized, and this could be the reason it acts up. Find an OBDI scanner and see if there are any codes. Look at the sensor outputs and verify that they all make sense.

 

have you pulled out a spark plug and check to see if it is running rich or lean??? Like pete says when its warm its in closed loop so reads all sensors for fueling, O2, MAF, MAP, coolant, throttle position.

Has the car always done this or is it a new car for you or a new problem?