alright here's the deal. suddenly, after a day of driving around town, which i have done a million times, the TA starts to cough, spit, sputter, and backfire...only if i try to go quite above idle. at idle all is fine. took to mechanic. replaced fuel filter at my request (i had put in seafoam after winter storage and had run 2 full tanks thru), and he noted that the diaphram in the EGR valve was sticking, so he unplugged it and capped off vacuume line. drove fine...until we drove it all day on and off and then again later in the day it started to do the same thing.

I had the ignition module tested and it passed inspection. they said the vacuum hose was off on the right of the throttle body and that the reconnection would help. well after about an hour of cruising it started coughing again. when trying to accelerate slightly more than idle it coughs and if i continue to pedal down it will kill. it has to be really warm and will run perfectly all day long at idle speed.

damn sick of this one and i cant think of any more to do. new plugs, wires, cap, and rotor as well.

 

Possibly the fuel pump is getting flaky. Drives fine for an hour or a day and then suddenly and instantly gets weird tells me it's something electrical in nature (in-tank electric fuel pump for instance), not a mechanical issue.

When the stock fuel pump in my 91 TBI Blazer went bad at 180K miles it acted exactly like you describe. Idles OK, but nothing under any load. Sometimes I could key it off and back again and it would work OK again for a while but eventually it would do it nearly all the time.

You can diagnose this by temporarily hooking up a remote fuel pressure gague that you can read while actually driving. If the fuel pressure takes a dive at the same time those symptoms start happening, you found your problem. A TBI system like your CFI engine should run at about 11-12 PSI.

 

PSI at 11.5 so all is good there.