02 gmarquis/miss or stumbling aceleration
 

hey everyone, ive got a prob. its been one thing after another here lately,i just replaced the intake manifold, fuel pump and filter. and while i had the top end apart i cleaned all fuel injectors and replaced the O rings for them. ive dumped alot of money into this car that i love but now it seems like its misses or something. if anyone has any ideas please let me know....... thanks

My question is why was all of these things replaced? Did they need replacing or has the engine not been running right, & you are throwing parts at it an attempt to fix because they may cause the problem. How about the simple stuff like spark plugs, coils, pcv valve.

Instead of throwing money at it, spend the money to have it diagnosed. Then you know where to go from there. I use to do computer diagnosis, & it only took about 10 minutes in most cases to find where the problem. Not all sensor problems produce a code, only those that are operating out of range. O2 sensors were probably the #1 problem that would not produce a code. That is because they still worked, but they were slow in responding, I always referred to them as lazy sensors & replaced them.

I understand DIY want to do it them selves, & you still can. But the wise DIY will spend the money for a computer analysis when he doesn't know where the problem is.

NO all I replaced needed to be replaced.it didnt all go bad at once but in time over a two month span. Fuel pump one week then a few weeks later the intake had cracked. Now its somthing with the accelation or like its missing. Ill check the plugs and coil packs now.i didnt think it would be them cuz I had replaced the plugs about 10 months ago and one coil pack. Thanks for the help. Ill post progress later.