Ok guys recent issue with my truck is that its been surging when iam at a constant speed like i just completly lift off the gas idle just surge up and down than i barley tap on the gas agian and she goes back to normal. Once this starts when i come to a stop she also surges up and down till she almost dies than shoots up and idles kinda high round 700rpm. Doesnt do it untile ive driven at least 15 or more miles. Ive replaced fuel pump eith a delphi pump about 3 months ago fuel filter ac del plugs ,wires,coil,cap,rotor,ignition module, pcv, cleaned the tbi put a new diaphram and spring on the regulator. No vac leaks. New idle air control and tps also. When it does it i deff smells rich. New universal cat converter also. Iam at my end right now to where i feel like selling it. I noticed that my spring was broken in the regulator and the new one i put in was shorter borg wsrner. Please help.

Forgot to menstion had s new egr valve didnt fix it plugged up the old one reinstalled it and no change there either. Did that incase there was some kind of egr leak.

 

I had the same problem on a 87 350 in my 79 K5, It was the injectors. The guy I bought it from had 2 different kinds installed. 1 would spray perfect and the other just kind of dribbel. You should be able to the spray from the injectors with air cleaner off. Went to junk yard got a whole TB took top off with injectors put it on mine, soon as I started it could tell the difference. I rebuilt the whole upper,new screens and O-rings and diaphram. Used the old injectors cause they match. Runs like a top now.
Bought this as a project and still am tring to figure were he left off on everything.