At cold start up, I turn the key, let the fuel pump prime, then crank. It doesn't take much cranking to start but.... on the first revolution of engine start up, it misses one or more cylinder ignitions. You can actually here and feel the miss. After that first set of misses (only a split second) it runs very smooth at idle. Also, I still suffer from some weak performance at low rpms (<2.5K). I'm used to driving manual transmission cars where you can really feel a miss. At low RPM's under load it feels like it may be missing randomly but its really hard to tell. It definitely isn't a very smooth acceleration or powerfull for that matter. Once the RPM are above 2500, the accelleration is smooth and powerful.

On warm startup, the engine cranks over and starts very smoothly (like it should).

I'm thinking that I may have a slow leak in an injector and will probably have them tested soon. I'm also wondering, does this vehicle have an EGR valve?
This weekend I'm going to pull the plugs and see what they look like. I just pulled the cap and rotor and looked underneath at the position sensor. Everything looked pretty good but I cleaned it up best I could anyway. I'm looking for suggestions at this point.

The plugs, wires, cap, and rotor are fairly new. Belly pan looks Ok (no oil puddles but some oil residue). Compression test was 150psi across all eight cylinders. Ran Sea Foam through intake (via brake booster vacuum). Also ran sea foam in full gas tank. Transmission fluid has just been changed and forward and reverse bands adjusted.

I just spoke to a technician at my local dodge dealer. Seems to be a pretty nice guy. I asked if they test injectors. He said that they do but they test the injectors IN the engine. (I was going to take them out and deliver them to someone to test them for me). He asked why I'm doing this so I explained my problem.
He proceded to tell me that my rough start could be caused by countless many things but is confident that his guys could figure it out in less than 2 man hours. Since the problem isn't severe, I'm not sure I want to spend the $120 to have them diagnose it. I'd like to figure it out myself if I can. He said it could be the throttle body, injector leak down, fuel pump(air in line), and probably some other things that I can't remember off hand. Are there any really good writeups on how to diagnose this stuff?

I asked if I had a miss would it throw a code and turn on the CEL. He said that a miss would definitely turn the light on. My light does not turn on or does it have any stored codes. So, if its not missing, why the weird start? Like I explained before, a few cylinders fire, then a slight pause, then the rest fire and it idles smooth. It never stalls (yet... and I'm knocking on wood). How does the computer detect a miss? if there is no fuel in the cylinder can it detect a miss? I'm thinking about the air in the line theory. If the air is being purged out when I'm starting up, one or more injectors could be shooting a blank into the cylinder. Then maybe the computer can't detect it.?

I am going to buy an O-ring kit and put them in. Its a cheap try until I figure out some other trouble shooting techniques. I'm also going to try and monitor my fuel pressure. I've never done this before but doesn't seem like it would be hard. If you have suggestions on how to do it, I'm listening.

 

I do believe they did away with EGR valves after the 96 model year.

A miss won't ALWAYS throw a code.

Check your IAC valve/motor on your throttle body. It could be dirty or sticking. It can cause hesitation on startup.

 

I took some pictures of my plugs and my IAC valve. I've been having a little trouble with starting. It starts every time but starts rough when cold and seems to idle just fine. I pulled all the plugs and the IAC Valve. #8 plug looks oil fouled to me and IAC was REALLY Dirty. Take a look and tell me what you think.

I cleaned up the IAC and plug #8 and it seemed to start better (cold). May be because #8 takes a little time to foul. We'll see.
#1 PLUG

#1 PLUG

#2 PLUG

#2 PLUG

#3 PLUG

#3 PLUG

#4 Plug

#4 Plug

#5 Plug

#5 Plug

#6 Plug

#6 Plug

#7 Plug

#7 Plug

#8 Plug

#8 Plug

IAC Valve BEFORE

IAC Valve BEFORE

IAC Valve AFTER

IAC Valve AFTER


Any and all input is welcome!!

 

#8 looks really bad. I would keep a close eye on it.

Defiantly check and clean your TB, and all parts on it. You can check for a slow leak on the injector by letting it sit for a day then pressing on the test port on the fuel rail and see if it has pressure in it. It will spray out at you so be careful. Check how much pressure comes out when you just shut it off then check the pressure after it has been sitting. If you don't have any pressure after sitting or very small amount I would suggest pulling out your injectors and having them rebuilt or even checked. This will show a leaking injector even if it is small.

On a second note you might have a bad valve seal dumping oil into the cylinder from the head. Thus showing signs of a miss fire. You might be in need of a head job.[sm=bangbang.gif]