Engine wont idle\stumbles on take off

[taro2413]

ok so where to start got the car for a $1000 as a work vehicle. after i purchased it i did a full tune up on it; plugs, wires, oil change, air filter, fuel filter, pcv, o2 sensor, replaced injector (was leaking), replaced pressure regulator, replaced emissions hoses from charcoal canister to tbi, map, pcv, and egr. also have new valve cover gasket but have not replaced yet (leak). all this about 4000 miles ago.
Ok so now the problem when ever under light throttle the engine surges and sputters but if under quick\heavy accel will not do this, but there is no power. And when i start the car it cranks for a good 5-10 seconds sometimes before it finally turns over. I also cant always tell if the pump is working in priming the fuel system when i turn the ignition on; so my thoughts are failing fuel pump. and upon fixing emissions lines car was blowing black smoke and debris form exhaust; my thought was carbon build up from emissions system operating unproperly for god knows how long. Only did this for about ten minutes total runtime, now still some smoke with slight tint of black. Very light smoke so hard to tell what color. still smells like fuel tho. Also check engine light is ON used to come on intermitant to driving car but is now always on.
Any one else have any thoughts? thanks!

[djoj]

hello
check your coil,i was having same problem,and if you think your fuel pump is going out ? was the car in use when you purchased it? you might have a dirty rusty tank that the fuel pump is clogging up ,disconnect fuel filter and turn key ,not start just key to see gas pouring out clean or dirty rust . i to have had these problems ,get back at me !!

[taro2413]

ok so testeed everything this weekend. everything checked out ok so took to mechanic for diagnostic. he says its the injector, its spraying way to much fuel. but injector is brand new so going to check out pressure regulator tonight. make sure its not bad or could also be facing wrong way. hoping thats whats wrong cuz injector is brand new 1 month old so we will see. thanks for the help man

[djoj]

wow !! let me know about that diagnostic , never heard about that ,but there's a pressure valve on top of fuel injector rail .take cap off press to release gas,see if it helps !!(try first ), i work out of town and just got in,but do check forum all weekend before i leave,keep me informed !! happy to help or i find people (mechanics) for info goodnight

[85 SE VIN 9]

You can hear the fuel pump relay snap, it's right behind your head. When cold I turn the ignition on and wait for the fuel pump to snap off, then turn to start. When hot this isn't necessary. I read somewhere that if you get too much fuel on the valves, like from a leaky injector, it can turn into a kind of mush on the valve that prevents it form closing or something.