Ok, i thought i would be able to figure this out without having too much trouble, but ive hit a point to where im fixing to start throwing parts at it. ive got a buddy with a 1999 Sport 318 w/ 5spd, rc 2 wd. Nice truck always seem to run good etc. But he came to me with a prob i thought might be easy to solve, wrong im a little stumped. It still runs fine but what it does is that when you start it up or run it all day, if you slow down to a stop, or need to put it in 1, or 2nd gear, if you give it more than 1/4 throttle, it like falls on its face, literally. ive never seen one do this, all vacuum lines are good, tb clean, new plugs, wires, cap/rotor, coil, and the cold air is clean. I cant figure out why this thing does this, and it also does it if you just free rev it too. But heres the catch, once you shift to third it stops, runs like it should. And if you free rev, no more than the 1/4 throttle all the way to the limiter, let it start to fall back down, you can stab it and it revs like it should. And it doesnt always do this, it just kinda does it when it feels like it lol. You can get in it and it will do it all day, other times you can give it hell from start to stop and it wont do it. Im just about out of options, the only thing i can think of is maybe the tps, but im not sure. And theres no check engine codes. Any info would be great.

 

I actually have a similar problem sometimes

 

ok guys, this is gettin serious... i noticed my truck kinda done this crap the other day. Now that i think about it my truck done it before with the auto, but only when i first started it occasionally, but i thought it was the auto goin bad so i didnt pay any attention to it. Mine done it for just a second but it snapped outta it. But it done it this morning and i just held it to the floor and it backfired!!!! But then all was well again. Come on guys need some help with this one, no codes, and it ain't the gas cap or nothing.

 

clogged cat? It's weird how it only does it at certain times.. Fuel filter clogged?

 

i dont think his cat is clogged, and my truck doesnt have one. i dont know about the filter, but prolly gonna pull the pump and all this weekend and check. I really dont know what it is.

 

It's weird how it only does it at certain times... Otherwise it probably wouldn't be to difficult to pinpoint a problem.

 

Ive found a small pattern if you would call it that. If its gonna do the stalling out, it does it when the rpms get down close to idle. When it does it wont rev up fast just sittin there if you mash it down, but if you keep on it revving it up, it will quit and rev like its supposed to, hence when you manage to get up to third gear youve revved it enough to make it stop. But as soon as the rpms get back down, it'll do it all over again. Im leaning towards a tps on this one, any ideas???

 

i would check the cat, take a piece of board and bang it on the cat( not to hard though don't want to mess up cat if it is not already) my dakota did the same thing but the i remove the cat and it ran just fine, if you said you checked everything else then i would assume it's the cat, but then again it could be the tps, i would check the cat first though, if that's it then you could just hollow it out(depending where you live, it should barly pass emission's) all i run is a glasspack, no cat or stock muffler.

 

Well its not the cat, i had that prob a long time ago with my truck, cut out the cat. Fixed it, and since my truck is doin this thing now that cant be it, since i no longer have a cat. And its not the cat on my buddies truck, cause his exhaust isnt restricted any, usually when the cat gets clogged it tends to start losing exhaust pressure out the back, quiets down, and even make a small whistling noise. And i replaced the tps on my truck, nothing. Im completely lost now, i have no direction to go. Help?

 

BTW this is still an ongoing problem. if anyone might have some new ideas?