Chosen Solution
my 1994 chevy suburban c1500 2wd is having problems. During acceleration it tries to fall flat on its face. Bogs way down and loses rpms. Idles kinda rough too. Thought the acceleration problem was fuel related. But I’ve changed the fuel pump and screen, fuel filter, and TPS. Rotor looks good as do contacts in cap. Seems alot worse when wet weather. Idling in N or P it only stumbles occasionally, but when in D or R it stumbles pretty badly, rpms seem low (like 300) and fluctuate by 100rpm or so. Even slow acceleration is no longer a guaranteed thing. Used to be hard acceleration would cause these symptoms but an easy acceleration wouldn’t. Now, doesn’t matter. Wants to fall flat on it’s face. Maybe bad distributor? TBI? I wouldn’t think it would cause this issue but O2 sensor?
does it start up okay without any issues? if your getting very weak acceleration and starting with a bit of a stumble every now and then on idle I’d check the plugs, fuel system and filter which you’ve already done and air intake first of all. could check for any clogged oil lines, I know you’ve ran sea foam but if there was already a pretty bad blockage then using it to loosen up other deposits may have collected in the same place. compression could also be a tad low, is your oil consumption normal?
Check if the Throttle body is dirty, if it is driven on shorter trips it can have build up that would cause that rough idling, though im not sure the slowing and stalling is part of that problem but worth a check and shouldnt take more than 15 minutes to check.
