Cylinder missing

[semlin]

true,l a clean plug or a plug that is carboned up more than the others will indicate h/g failure. In the early stages the plug gets covered with carbon washing off the cyvliner then it is cleaned once all the carbon is gone. an electrical misfire might clean the plugs but won't dislodge the carbon. so divide my suggestion in half.

i still think given the timing this is not a h/g issue but no harm in checking

changing that plug or switching it over to another cylinder is definitely a good idea.

if you kept your old cap, rotor and wires as spares, now is the time to make use of them.

 

[Poriomania]

One thing you might also try is do a brake stand in both drive and reverse and see if the truck behaves differently. We've see it where under load the engine will torque and produce an electrical problem. Since the motor torques in opposite directions between drive and reverse it might not show up in reverse which would help eliminate some of the searching.

Okay, so maybe it is electrical. I just tried this and I had no problems in reverse, but it stuttered very badly in drive.

 

[semlin]

good call Rick!

sound like the harness was not fixed. try tiugging at where they fixed it while at idle to see if it stutters.

 

[landtank]

Glad you were able to recreate the problem. Would have been nicer if it was a plug.

If and when I have an issue with this harness the repair will be a new one. But I hate these sort of things and have to deal with harness failures quite often for my job and experience has tought me that there is nothing like brand new in these cases. It's a long snaking SOB to get at but it would be the way I go.

 

[Poriomania]

I got in closer, and I am pissed! The dealership I took it to last week told me they found a "break in the harness" and got it running, still with a miss. I get into the harness by the EGR valve, and they didn't do an thing! The heat tape was burnt through as was the wiring! I can see the copper!

 

[semlin]

great. you are half way there. If you choose to splice it to fix it, may I recommend

-marine grade double butt connectors (like a regular butt connector except that each wire has its own pinch)
-heat shrink wrap for each connection
-a small piece new heat wrap (cheapest place is a truck parts place where they sell rolls of it)

you will want a shop vac to suck away the crumbling oem heat wrap as you take it off. I fixed mine during the h/g repair so I had the intake manifold off but I think you can get enough room if you remove the t-body, egr valve and disconnect the harness from the firewall. Just watch you don't stress the injector connector wires.

 

[Poriomania]

great. you are half way there. If you choose to splice it to fix it, may I recommend

-marine grade double butt connectors (like a regular butt connector except that each wire has its own pinch)
-heat shrink wrap for each connection
-a small piece new heat wrap (cheapest place is a truck parts place where they sell rolls of it)

you will want a shop vac to suck away the crumbling oem heat wrap as you take it off. I fixed mine during the h/g repair so I had the intake manifold off but I think you can get enough room if you remove the t-body, egr valve and disconnect the harness from the firewall. Just watch you don't stress the injector connector wires.

What gauge wire did you use?

 

[semlin]

i didn't have to patch my harness but i think everything is 16 gauge or maybe 14. It was PM during my head gasket repair. the heat wrap just fell apart into dust but the wires were still ok underneath. the repair suggestion comes from wiring a honda civic after an engine swap, and other wiring to my boat and trailer. now that i have found double ended butt connectors I just want to tell the world .

 

[landtank]

I have no experience with marine butt connectors but I'm a solder/shrink tubing repair guy. A butane torch found at Radio Shack is perfect for an outdoor repair such as this, for both soldering and shrinking the tubing.

 

[CJF]

One thing you might also try is do a brake stand in both drive and reverse and see if the truck behaves differently.

Dat was a nice catch!

 

[Poriomania]

Finally resolved by splicing and covering the shorted wires in the harness by the EGR valve. Wrapped up nice and tight with some heat shield. I talked to the dealer today and the part of the harness they worked on was at the battery, actually on the battery, no where near the problem I found.

Thanks for everyone's help.