Time for timing chain.

[1990LTD]

cool. my water pump is pretty new, hopefully it's still reuseable. probably only 5000 km on it.

[Piece-it pete]

Oh yeah I meant to ask - the chain I took off was a single row, but I couldn't find any hint of plastic. I assume it wasn't original?

Pete

[gadget73]

possible. The plastic would have been on the cam gear. Usually you can tell because its a distinctly different color. Or, it all fell off. Was there a Ford part number cast into it? If not, its not original. I think the plastic one had some 1970s part number.

[Neal 97 250]

The one I took off the explorer engine I had was a single roller all metal. No plastic gears.
2001 engine

[gadget73]

yeah those are single row. They also stretch more than the doubles, but not enough to be a serious issue and they don't shed chunks into the pan that can make the motor blow up. I've seen several people with 84-85 cars that lost engines because the plastic failed entirely and the chain jumped. I don't honestly know of anyone who's lost an oil pump because of chunkage but I just have a general dislike of the notion of solid things that don't belong in the oil pan being in the oil pan. It seems like a good way to have a problem.

[Piece-it pete]

I had plastic teeth on a 79 GM 350 that stripped. I was told to drop the pan and clean it, never did. Sold it a few months later so I don't know what happened down the road.

I finally got a good highway run on the old 85, and surprise! The odd miss is still there.

And it's actually worse. I suspect the slack in the timing chain was covering it up a little because it comes through clearer now. It 'coughs' slightly occasionally while straight line cruising for no apparent reason. I doubt a non carworking person would consciencely notice it.

Reminder, it's an EEC-IV. Any ideas?

Pete

[sly]

weak valve spring that's not seating all the way every time?

that... or it's dieseling on that cyl due to hot buildup on the piston?

don't really know... but considering the age... that could be it.

[1987cp]

Could always get out your handy Harbor Freight leakdown test kit ....

I need to do that myself one of these days. Stupid engines that always have a random odd miss at idle ........

[gadget73]

back to basics for a minute, are all the tuneup parts in good shape? No old wires or crusty plugs or anything like that? These occasionally foul the rear plugs when the motor starts to get tired. You'll get a random miss if the plugs are crusted up. If 4 and/or 8 are crusty and the rest look OK, that probably means the valve guides are done for. The motor tilts back a bit and you'll get a little more oil on those cylinders than others. At least thats my WAG as to why its just those 2 that seem most prone to oil fouling.

[Southern_Pride]

I'm with gadget. My 91 would foul the #8 plug all the time and make a miss. I finally got tired of changing it and opened it to like 120 thousandths and never had a problem again.

[Piece-it pete]

The wires and plugs *should* be ok. I'll pull 4 and 8 this weekend and take a look.

If it ends up being springs guides or valves etc I'll call it good I'm beginning to suspect the engine's about had it anyway.

For carbon buildup, can I use the old pour-water-in-the-'carb' trick?

Pete

[Piece-it pete]

Update: plugs were OK. For now I'm calling it all good, and linking this to my readers' rides thread

Pete