Bad Jerk and Idle Once Warmed Up

[nascarfan2]

Hey everyone,

Im looking for a little help with a big problem I have and have been working on for the past few weeks. A few weeks ago I was driving home from class and all of the sudden started missing more at idle. Then when I would go take off the car would run really sluggish and jerk really bad. Even if I help the throttle wide open I couldnt get past like 2000 rpms or anything, and it would jerk back and forth really bad. It ran fine for about 40 minutes or so and then started doing this problem.

Now everytime once the car warms up, after about 5 to 10 minutes it starts jerking and losing power bad. I just replaced the pump in it a month and a half ago and didn't have the money to get a afpr with it. So im still on the stock one. I could see that being overrun by the 255, but don't understand why it wouldnt do it right away.

I noticed to that after I replaced the pump the car became a lot harder to start. It would take me a few times of cranking it to get it started. Whenever I have the jerk and loss of power by a/f gauge drops to full lean or off the chart, and it looked like my plugs were white, but I dont think its just them thats the cause. I am running NGK BPR7ES gapped at what was specified in my manual.

Ive done tests on my coil, and wires and those checked out fine. I changed the fuel filter and that didnt change anything. Im not throwing a CEL at all, so I dont know whether or not it could be a bad sensor. Ive only run 93 octane fuel in it, and dont see how if it was bad fuel it would be fine until it warms up and then give me problems. I am going to do a boost leak check, but I would think a boost leak would give me problems from the moment I start the car. My BOV is recirculated, so I dont think thats the problem.

I am completely lost here and would really appreciate any help. Thanks!
~Jake~

 

[joe_mopar]

Sounds like you need to check the fuel pressure.

 

[nascarfan2]

What would cause the engine to run fine initially and then run bad once warmed up in terms of the fuel pressure?

 

[jamesbadgley]

check for vacuum leaks or rips in your air intake hose.

 

[schroder]

Boost leak test sir. Also, check timing on the car...both mechanical and electircal.

 

[yoshi_tony]

mine did the exact same thing it was full of boost leaks specially on the throttle body it wouldnt even get 1 psi of pressure doing the test but while driving it would boost