losing power at 3k rpm??

noticed today when i was driving on the interstate that at around 3k rpm my truck seems to not be getting enough fuel?? if i let off just a little on the throttle it seems to pick up just fine, between 2.5-3k it seems to struggle. keep in mind i just did a tune up earlier today.

i copied this image from another thread on this site about adjusting the carb at idle. ignore the red writing, im just talkin about the black arrows


Arrow #1: is there supposed to be a second throttle cable for this? or does the main throttle engage it where arrow #2 is at? i noticed when i twisted the throttle the second one didnt budge at all, but when i applied pressure to where arrow #2 is, they both moved, is this supposed to move at the same time, or is it like a delay thing, more throttle means more fuel, then both move? or are they supposed to be moving from idle to full throttle?



any help would be appreciated, this is my 1st go around with a carb motor, so im lost as crap when it comes to this stuff. any input is greatly appreciated.

Ok did you replace your fuel filter? Next I will go on the idea that your egr valve just below the carb has it ever been removed and cleaned out.In short 3 ten mm bolts,one vac line,one elec conn. Remove it note the gasket position on it 1st,then clean with carb cleaner and a toothbrush works good.Make sure the metal pintal inside moves back and forth freely with a flat hd screwdrvr.Next pull your charge air pipe cover(has those 3 blk hoses going to it on the front) remove check and or replace those filters and IF your pre convertor below the exhauast manifold has never been touched remove it and clean it out with brake cleaner or punch out those screens inside.It catches alot of carbon and can restrict air flow! How is your cat convertor wayyyy old,you might want to replace it! I am not saying your carb is part of the problem but,air restriction on these trks is super bad even at hwy spd,and I would remove and or replace those filters in your charge air (you can use any style foam filter or pcv filter and cut to size for the small filter housing) I do.To remove your pre- convertor it has to come out from the bottom so lube it with some liquid wrench on the bolts and nuts a day or two before you yank it out.Makes it alot easier breaking loose these items.I would replace those gaskets for the exh system and those part #s are listed in post up parts link in general I think.Unless your carb linkage is sticking some,idk running out of gas so I will end here.I will follow up with more later.Hope this helps and may others add or correct me if need be.

" target="_blank should have the exhaust gaskets for the pre- convertor here!

The other cable pull you asked about is for the cruise control if your truck had it..and to add to 87 forever, you might want to double check the timing of the engine a lot of people advance timing to compensate for worn out ignition systems.. also.. make sure the vacuum line coming off the vacuum advance on the distributor is connected and not obstructed..could also be a tired carb..that's the "not cool" answer though..does it only do it while its hot or does it act up all the time?

All the time

Thanks for the advice guys! I'm in the process of replacing my entire exhaust system, should be Doug it this weekend. I'll also check out the other things you guys have mentioned. I'll post with some updates. Also I think the timing might be off because the motor shakes at idle, but smooths out if I play with the throttle... Motor mounts??? Timing??? Thanks guys

Check the EGR valve. If it's not closing completely, then your idle will be bad to nonexistent.

Thanks cusser, I'll check that out to

fuel filter came in today, i also found a can of PB Blaster and some Carb/Choke Cleaner, post some more updates tomorrow.

fuel filter is changed, i took a look at the pcv valve, and its good to go. theres a screen that was inside the air box. that was covered in oil. so i cleaned that. took a look at the carb and it looks like it was changed recently, same with the egr valve, truck still runs like shit, it has trouble starting. but i think its the timing. going to a shop in about 30 mins to have them check my timing since i dont have a place of my own to do it. also im getting a new exhause system tomorrow from the headers back.