New to the club, hopeful I can get help. I love these forums, and have been helped greatly with my boat on a similar kind of page.
I just bought a 99 Suburban forest service rig with 42,000 original miles. It ran great when I got it, and as a pre-emptive measure, I put in new plugs, wires, cap and rotor. It still ran great. As far as I could tell, the plugs were clean and original.
Here's what has happened since:
After about 100 miles, it began to miss intermittently while sitting at idle. By 300 miles, it was running rough, chugging, and making lots of water out of the tailpipe.
I replaced fuel filter, uphill O2 sensors, and air filter. Still ran rough, so I took it in.
There were no diagnostic codes, but replacing plugs, cap and rotor fixed the problem. They told me that the E3 plugs I had put in were to blame. They replaced with iridium plugs and an AC delco cap and rotor.
That was Monday. After 100 miles, again it was missing intermittently at idle, and now here at 300 miles, it is running rough and chugging again.
What is going on here?
---------- Post added at 02:35 AM ---------- Previous post was at 01:56 AM ----------
..sorry, by the way 5.7L 2500 4X4.
I have been browsing some ignition posts, and am curious about the following note, below, regarding a vent at the bottom of the distributor. I haven't looked at the bottom of the distributor, but has anyone else had this experience? I'll get at it tomorrow, and I know what I'll find: charring in the cap and wet plugs. Should I gap them down?
I just bought a 99 Suburban forest service rig with 42,000 original miles. It ran great when I got it, and as a pre-emptive measure, I put in new plugs, wires, cap and rotor. It still ran great. As far as I could tell, the plugs were clean and original.
Here's what has happened since:
After about 100 miles, it began to miss intermittently while sitting at idle. By 300 miles, it was running rough, chugging, and making lots of water out of the tailpipe.
I replaced fuel filter, uphill O2 sensors, and air filter. Still ran rough, so I took it in.
There were no diagnostic codes, but replacing plugs, cap and rotor fixed the problem. They told me that the E3 plugs I had put in were to blame. They replaced with iridium plugs and an AC delco cap and rotor.
That was Monday. After 100 miles, again it was missing intermittently at idle, and now here at 300 miles, it is running rough and chugging again.
What is going on here?
---------- Post added at 02:35 AM ---------- Previous post was at 01:56 AM ----------
..sorry, by the way 5.7L 2500 4X4.
I have been browsing some ignition posts, and am curious about the following note, below, regarding a vent at the bottom of the distributor. I haven't looked at the bottom of the distributor, but has anyone else had this experience? I'll get at it tomorrow, and I know what I'll find: charring in the cap and wet plugs. Should I gap them down?
I would go back to the ignition. You said the cap looked terrible shortly after the tuneup. Use only Genuine AC Delco plugs, cap, rotor. For wire, use AC or NAPA Premium. For plugs, just get the boring old fashioned single electrode platinums. This is what your parts guy will give you. Most importantly, set your gap down to .040. The bigger gap put a tremendous load on your ignition system, and doesn't offer any benefit. One last thing. There should be a vent hole in the bottom of your distributor. If the screen is still there, knock it out. It will allow the distributor to breath much better, and stay dry.
And there is no timing adjustment on these trucks.
And there is no timing adjustment on these trucks.