98 Dodge Ram 1500 5.2L all stock cept cold air intake, Magnaflow Exhaust and Cat Delete.
Fuel pump replaced less then 5K miles ago.
I have 2 Problems trying to deal with.

What im experiencing is that when the vechile is cold it has a hard time starting. I just got done replacing the intake manifold and pan gaskets. Leak tested and looks good.i also replaced the cap, rotor, wires plugs. The hard starting, started after i replaced the manifold gaskets. i check all vaccum lines and all sensors all plugged in and no leaks. I sprayed Brake cleaner around the manifold to double check for leaks, no rise in rpm or nothing. I've read around and searched around on numerous Dodge forums but cant find an answer to this problem. i pulled the IAC valve out of the throttle body. Cleaned all the carbon build up off IAC and no difference. I haven't tested the TPS. Because i do not have a multimeter to do so. If i hold the gas pedel down a tiny bit the truck will start fine. but then die out like its not getting enough air/fuel or something. once the truck warms up to operating temp. it still idles low. around 600 rpm give or take 50rpm.. any ideas is appreciated since i need this as my daily driver and for my sons Doctors appointments in 2 days. Brian

 

Did you clean the IAC well in the throttle body itself as well? Reset PCM after doing so?

Still sounds like a possible IAC issue.

 

my first reaction to "bucking while driving" was low fuel pressure/starving for fuel.
do you have any way to check the fuel pressure. should be about 49 psi, +/-5

my next thought on "cranks better with throttle cracked open" is the IAC is not working right. you should have a cold idle of about 1000 rpm and as the truck warms up, a slow drop down to about 600 rpm when at normal temp. if its not doing this, i'd replace IAC.

has it always done this or did it just start it?
did it do any different or better before fuel pump was replaced? or after?

 

Before i did the manifold gaskets the truck would start & idle fine. But now that i have done the gaskets this is what started. I cleaned the IAC but did not reset the computer.. when i did the manifold gaskets i did clean the intake manifold. and the sensor that is located behind the alternator, top/ pass side i did get a little wet with water. on accident. i think i might try to replace the IAC. I dont think that the fuel has a issue since it ran and started fine before manifold gaskets replaced. Its a brand new fuel pump & Filter, I also do not at this time have away to check the fuel pressure.

 

Just try resetting the pcm first. if you shuffle sensors, PCM needs to figger out what "zero" values are again.

 

If the plenum gasket was blown, so is the cat and the o2 sensors. And for the life of me, I don't know why people do work on their rides without removing the negative battery cable FIRST.

 

if u read the first post i wrote in my description of the truck. I DONT have a cat. ie.. CAT DELETE...

98 Dodge Ram 1500 5.2L all stock cept cold air intake, Magnaflow Exhaust and Cat Delete.
Fuel pump replaced less then 5K miles ago.
I have 2 Problems trying to deal with.

and for the battery cables yes.. i did the negitive first then the positive..

 

Sorry, I missed the cat delete. Any chance you replaced the fuel pump with a Carter?

 

whatever advance auto parts in florida sells... i wanted to say it was a carter maybe... my buddy works there as i get most parts from him for cheaper...

 

As i mentioned earlier.. the surges/ bucks while trying maintain speed. you can only feel it between about 20mph-60mph.. any ideas on that? that is my main concern for now.. as i need the truck for about 100mile trip for sons doctors apointments