First of all I want to say this is a great forum! I have got some great information by researching past threads. Unfortunately, not quite enough to fix this problem...
My daughter was driving the 1999 Ram 1500 (5.2L) a week and a half ago on a sub-zero day and called stranded on an on ramp. She said it was running not quite right, then puked out as she slowed. I went down and limped it home. It ran out "OK" at road speed, but stalled at idle. The code I got was a P0300: General Misfire (duh!). Cleared that and checked everything obvious over. I ran it again and after a time got P0172: Bank 1 too rich (or something like that) I changed the plugs as I was unsure when they had been changed (I bought the truck a year ago). They looked OK except #4 had some carbon and #8 looked terrible, almost half burned off. I thought that had to be it, but no. The next try a P0204: Injector 4 open. I checked the injector and got 12.xx ohms... same as the others. Cleared those and got a P0203 and Injector 3 ohmed OK. The rough idle research I did prompted me to change the IAC which didn't help.
The smoke made me look at the oxygen sensor. I had replaced the downstream this fall so I questioned the upstream. The weird thing was that I could unplug it and run without setting a code? I read this era trucks may not catch the O2 sensor faults reliably, but still no joy.
During my reads it was mentioned that #8 plug fouling was a symptom of a plugged catalytic converter. I rigged a gauge up to the threads on the old O2 sensor and noticed the exhaust pressure would spike when the cat rattled. And again I found "the answer" and drilled some holes and hollowed it out. And again I was wrong.
On my combination test drive and hole plug run after reaming out the cat, I set a P0203, cleared it and set it again on the way home. I swapped the #3 injector with the #1 injector and went to get some gas (I have gone though a half tank just troubleshooting) I set P0203 again on the way to the station and again on the way home.
I downloaded the pin out and the wire has continuity from the ECM to the injector. I also put a 194 bulb in the injector plug and get a light when turning over.
So now what? I am out of ideas.
Sorry for the long post.
Thanks
My daughter was driving the 1999 Ram 1500 (5.2L) a week and a half ago on a sub-zero day and called stranded on an on ramp. She said it was running not quite right, then puked out as she slowed. I went down and limped it home. It ran out "OK" at road speed, but stalled at idle. The code I got was a P0300: General Misfire (duh!). Cleared that and checked everything obvious over. I ran it again and after a time got P0172: Bank 1 too rich (or something like that) I changed the plugs as I was unsure when they had been changed (I bought the truck a year ago). They looked OK except #4 had some carbon and #8 looked terrible, almost half burned off. I thought that had to be it, but no. The next try a P0204: Injector 4 open. I checked the injector and got 12.xx ohms... same as the others. Cleared those and got a P0203 and Injector 3 ohmed OK. The rough idle research I did prompted me to change the IAC which didn't help.
The smoke made me look at the oxygen sensor. I had replaced the downstream this fall so I questioned the upstream. The weird thing was that I could unplug it and run without setting a code? I read this era trucks may not catch the O2 sensor faults reliably, but still no joy.
During my reads it was mentioned that #8 plug fouling was a symptom of a plugged catalytic converter. I rigged a gauge up to the threads on the old O2 sensor and noticed the exhaust pressure would spike when the cat rattled. And again I found "the answer" and drilled some holes and hollowed it out. And again I was wrong.
On my combination test drive and hole plug run after reaming out the cat, I set a P0203, cleared it and set it again on the way home. I swapped the #3 injector with the #1 injector and went to get some gas (I have gone though a half tank just troubleshooting) I set P0203 again on the way to the station and again on the way home.
I downloaded the pin out and the wire has continuity from the ECM to the injector. I also put a 194 bulb in the injector plug and get a light when turning over.
So now what? I am out of ideas.
Sorry for the long post.
Thanks