2.9 engine miss?

[Spitfire1975]

I am going to check the spark consistency from the rotor too....

 

[Spitfire1975]

The base timing is set at a deadperfect 10*. Doesn't jump skip...nothing. Just holds dead steady.

 

[Bronco_Chuck]

its possable. bad grounds can do the crazyest things.

 

[Spitfire1975]

found a cause for the most recent intermittent spark. Didn't hook the FPR vacuum back up. Once I did that....no spark issue. Coil spark is unbroken.... Still idling like crap. Smells like it is running rich and is blowing the 13 and 73 codes (first test) and a 13 and 72 (second test) Koeo test gives me an 11. Can't keep it running without my foot on the throttle and a MASSIVE amount of rich smelling exhaust

 

[Spitfire1975]

Why is it every time I add a new sensor the thing runs worse? I thought a tuneup was supposed to be a good thing....

 

[adsm08]

you change a sensor, it gives a better signal that looks different from what it expects, so it has to adjust. Also, have you been disconnecting the battery?

 

[Spitfire1975]

I have only disconnected the battery twice. Tonight and when I swapped computers. Everything sensor-wise in this thing has been either changed or tested ok (or swapped with so many of the same there is no way they could ALL be bad). I am down to either 1. Plugged cats throwing off the O2 sensor 2. something wrong with the injectors or 3. something wrong with the fuel pump(s). Fuel pressure by the way is 30 when running. As soon as you turn it off, the pressure goes up to 36-37. Don't the injectors need closer to 40 to work properly? Compression is great, although I haven't done a leak down on it.

 

[Spitfire1975]

Does the following sound correct? gonna try it tomorrow.

"The easiest test for converter plugging is done with a vacuum gauge. Connect the gauge to a source of intake vacuum on the intake manifold, carburetor or throttle body. Note the reading at idle, then raise and hold engine speed at 2,500. The needle will drop when you first open the throttle, but should then rise and stabilize. If the vacuum reading starts to drop, pressure may be backing up in the exhaust system"

 

[Spitfire1975]

did the vacuum test right now. Looked good. goddamn it. Held steady at 23 in. Quick drop to 18 when I hit the throttle. I am assuming that since it holds steady, there is also no problem with valve guides, etc...

 

[Spitfire1975]

I am getting frustrated.........

 

[Spitfire1975]

A thought......the O2 sensor wires were hanging a little to close to the y pipe when I changed it. Maybe the connector is damaged internally and not making a good connection, thereby running rich? maybe I need to cut out the connector and wire it direct?

 

[Chris88GT]

Have you checked the coil? I just started reading this thread yesterday so sorry if you have. I have a Dakota that had really similar problems along with a stumble under load, and it ended up being the coil. If you have a Haynes manual it will tell you how to ohm it out. (It did in the Dodge book) Mine was right on the edge of the acceptable ranges. Swapped it out and it ran like a champ...for a while... it has loads of other issues.

Just something to check if you haven't already.

 

[Spitfire1975]

You mean this?

Use an ohm meter and probe the resistance of the two small terminals, and you should find 0.3 to 1.0 ohm. If the resistance is not ok, it may be a bad coil. If the resistance is ok, probe one small terminal and the coil wire terminal. Resistance should be 8000 to 11,500 ohms. If the resistance is not ok, replace coil.

Checked both of mine just now. Truck coil resistance was actually low at ~7000.
Spare coil is on the low end at ~8150.

Both of these coils have been in the truck with no difference in performance, but they ARE similar in resistance so that makes sense. Would the coil contribute to the rich condition and if so, how? Just want to make sure if I go buy a coil (which it looks like I will have to do regardless) that it is going to make some kind of difference in its running abilities.
I am starting to lose serious man-points here.....

 

[kimcrwbr1]

did you disconnect the battery when you canged the emission parts the computer will run on the old values take the neg terminal off the battery for 15 mins erase all the on demand codes then take it for a spin for about 10 or 15 minutes at medium speeds to set the new values then test it again

 

[kimcrwbr1]

and make sure everything is plugged in elect and vacuum that was one of my mistakes and it takes at least 15 min to reset the computer with batt disconnected