i have a 99 dodge ram 1500. it has a 5.2l v8.

i had blown the ignition/acc fuse and i replaced it but when i went to start it, it wouldn't start, i could here the starter running and it was turning the belts but it wouldn't fire. if i started it and gave it gas it would fire up but if i took my foot off the peddle it would die. so i did some research and most people were saying to let the fuel pump cycle two-three times then start it and it worked but a couple of days later it happened again so i cycled the fuel pump again and it worked but when i gave it gas it would climb but when it was coming back down to idle it was go past the idle speed and stutter, sometimes even die so i decided to clean my throttle body and when i went to test it. it fired up first time and ran beautiful. well two days later(today) i went to go start my truck and it starts but when it starts and goes to idle it drops down past idle like before and stutters (sometimes dies) then goes back to idle speed and if i give it gas it climbs then goes passed idle and stutters and sometimes dies.

i've tried everything i know and i cant figure it out.

any help would be awesome

 

lack of idle that is solved by pressing the gas pedal a little bit is usually related to either IAC (idle air control) or TPS (throttle position sensor) or weak battery/low voltage.

the IAC will not work correctly if you have low battery voltage. this is common after a dead battery, jump start, alternator problem, lights left on, etc - and will correct itself if you fix the low voltage.

you got a multimeter? check your battery voltage and verify its at 12v or above.
reset PCM. disconnect neg battery cable and turn on headlights for 30 seconds. reconnect and crank it up. press the gas pedal lightly a few times for the pcm to relearn everything.

if it runs ok with your foot on the gas pedal, its NOT fuel pump.

if it doesn't fix itself, replace the IAC and be sure and clean the well it fits into, and the hole in the bottom, and don't forget the o-ring.

 

i checked the voltage on the battery and i was reading 12.33v i pulled the negative terminal and turned on the headlights for 30 sec like you said and it didn't work it still struggles when going back to idle. I'm gonna take the throttle body back off tomorrow and check that o-ring cause i didn't know there was one. maybe the o-ring is bad. but i have another question, when i went to start it it sounded like the starter was seized. that had happened before and what i did to get it to work again was take the negative cable for my Dixie horn off and the starter turns fine. could the horn and my amp be drawing to much power and messing with the iac?

again any help would be greatly appreciated.

 

yes....

 

ok ill try it tomorrow. any idea as to how i can hook them up so it wont draw to much power

 

well the rain stopped so i went out to try the truck with out the amp or horn hooked up and its still doing it. so tomorrow i will take the tb off and check that o ring. if you think of anything else i should try it would be greatly appreciated

 

Try cleaning IAC pintle and the port hole in TB. A gasket leak below the TB would cause a high idle by allowing more unmetered air.

 

o-ring is around the outer body of the IAC and fits into the port. if left off, would create a vac leak that would increase idle, not decrease it. no need to check the old one or remove throttle body.

i only said don't forget the o-ring because if you replace the IAC, the o-ring is often loose in the box and easy to overlook.

you can try cleaning the old IAC, but i don't know if its worth the trouble. you can replace it for about $40-50 from your local parts store.

 

well i went to start it today to see if it did it before i tried cleaning the IAC and it ran fine... but then like an hour later it started to do it again. by then i just shut the truck off and walked away lol

im really confused as to what it could be.

ill check it tomorrow before work and if it still does it ill clean it monday

if anyone thinks of anything please let me know

 

I had the same issue... I went the route of plenum gasket and throttle body clean. After, the IAC sounded like a buzz saw. The sound when away but still stalled. The new IAC came, installed it and it runs great.