gdstock - Thanks; I've checked and re-checked the connection of the harness to the PCM, and they're as clean, shiny, and secure as they're gonna get.

** Edit - the picture finally came up, which prompted me to lean on the PCM connector with a 34-ounce Louisville Slugger with the engine running. No joy.

Hahns5.2 - "Single wire sender is for the gauge, two wire sensor is for the PCM, doesn't matter where they go".

Well that confirms what I thought then; NAPA has their part numbers backwards. They told me the one-pin sensor with the plug that goes in only one way was for the PCM, and that the two-pin connector that seems to go in either way was for the gauge. There isn't enough slack in the wiring harness to switch locations, so as it stands I have what I think is the PCM temp sensor installed on the top front center of the intake manifold, and the temp gauge sender mounted just aft of the alternator. Either way, they each are attached to the correct connector, so as you say, I guess the location doesn't really matter.

I think it's time to bring back carburetors, points, and manual chokes. Who's with me?

 

, it's fixed!


Runs great!

Drinks for all my friends!

This dancing banana guy looks sad compared to me!


zman is a genius!



OK .... the resolution;

Just as zman first suspected, it was indeed the crank sensor. Now we know for a fact that a failing/bad CKPS can cause intermittent and/or weak firing on particular cylinders, and particular cylinders only. (Number four was always the worst, followed by 5, 6, and seven. For now, I think it was just a coincidence that they're sequential).

It seemed more and more likely to me that it would be the crank sensor, since that seemed to be the only component that was cylinder-specific. What I think was going on was that it was simply on the way out, and not doing well at detecting the cutouts on the [flywheel]. (It's an automatic, but I'm gonna call it the flywheel). Some it was reading better/more quickly than others, and sometimes not at all. What I couldn't quite get past was the notion that the PCM would either see a signal or not, and fire the coil or not. Then it dawned on me that the PCM might just be getting signals from certain cylinders (via the CKPS) just a little too late (or not at all) to allow it to ground the coil for a period of time sufficient for a decent charge to build up in it; hence the weak or missing sparks.

So that's it; this case is closed, and I now have a lifetime supply of caps, rotors, and wires. The engine is running like a stock 318 should, and I couldn't be happier. It starts RIGHT up, purrs like a kitten, and has plenty of power even after 160K miles. On my test drive it accelerated from 30 to 40 in about 3 seconds, and about the same from 40 to 50. Very sweet; so sweet in fact that I don't even give a crap that the Red Bums just added one of the worst chapters ever to their long history of chokes, failures, and screw-ups. And there's always the Patriots! (I know zman, they suck - whatever).

So thanks for all your help you guys; I now know more about my engine than I ever did (and possibly more than I ever wanted to know!).

Happy motoring, John D

 

YEA, I was right about about something for a change! LOL JK

Now you can start working on fixing them SOX.

 

Glad you found the problem!

(Go Rangers!)

 

"Now you can start working on fixing them SOX".

Some things can be fixed, some things can't. LOL

I left out a potentially valuable piece of information. What ultimately prompted my to throw down a whopping 48 bucks on the cheapest, crappiest CKPS I could find was the fact that my old one showed infinite resistance between any two terminals, and the new one showed about [3.8 on the 20K ohm scale - not sure if that's 3.8 ohms, or 3800] between the first and second pins. That looked encouraging, so in it went. (Understandably, they wouldn't let me just try it and return it if it wasn't the problem, long-time customer or no). Their more expensive ($129) one read the same as the cheap one. If it ever craps out again I think I'll know what the problem is, and I'll spring for genuine Chrysler at that point.

Now excuse me while I go start up my van and listen to it purr.

 

Now there is some useful information. I learned something here too.

Awesome. (here's one to file away for future reference......)

 

What brand did you get? You know, besides OEM, Standard Motor products are pretty damn reliable as far as I'm concerned.

 

You know John, I couldn't really tell you, other than it was branded NAPA/Echlin. I'll see if I can find out who really makes it. I've always had very, very good luck with anything I've ever bought through NAPA, so who knows, maybe some of it is made by Standard. Good to know that's a reliable brand in your opinion (which carries a lot of weight with me).

Just for what it's worth/if anyone cares, NAPA tends to have two levels of quality on most of their sensors; the part numbers are identical except for the suffix "SB" on the cheaper stuff. For example, the $129 CKPS is p/n CSS602, and the $48 one is CSS602SB. Sometimes I go for the better stuff, like the cap; for maybe an extra 5 bucks, you get copper "contacts" instead of aluminum; for the coil, it was maybe another $25 to get a copper center post, so I passed.

The premium stuff is prominently branded "Napa Echlin" and comes in the blue and orange box; the budget line is branded "Napa/Mileage Plus", comes in a more toned-down box, and still says Napa Echlin in the fine print. And both lines are "Hecho en Mexico" (at least the boxes that I have in front of me), so you know it's got to be "beuno".

***

Brian - yes, this has been interesting. I'm liking my theory one why a weak spark, and not just "no spark". Thanks for your help!

gdstock - Thanks, I'm so glad this is over with. And I'd root for the Rangers except I already told zman I'd support the Damn Yankees

So may the best team win .... or the Yankees, whichever LOL

 

hahaha, might be some flack coming this way as far as the Yankees go. Anyway, I was just hoping you didn't use Duracrap. BWD is even better than that.

And I think I need to change my profile pic for the playoffs or at least until they win #28.

 

More interesting stuff; Standard Motor Products owns Echlin.

From napaechlin.com, "History":

http://www.napaechlin.com/Welcome+to...y/Content.aspx

Jack and Earl Echlin founded Echlin and Echlin in San Francisco in 1924. They manufactured automotive replacement parts such as igniter gears and oil pump gears. Eventually, they bought a small ignition company and went on to become one of the leading U.S. ignition manufacturers ....

In 1928, Echlin signed a contract to supply oil pump and ignition gears to the National Automotive Parts Association (NAPA) which, in turn, distributed those parts to garages across the country. Soon after Echlin began supplying ignition parts as well, and this was the beginning of what has become a lifelong relationship between NAPA and the Echlin brand.. NAPA became recognized as one of the most efficient distributors in the automotive parts market ....

In May of 1998, Echlin agreed to be acquired by Dana Corp. At the time, the Dana deal created an auto parts colossus but five years later in February of 2003 Dana agreed to sell a significant portion of the Engine Management operations of its Automotive Aftermarket Group to Standard Motor Products, and the Echlin brand joined the SMP family. Standard Motor Products continues to enhance and support the Echlin brand by strengthening the partnership with NAPA and positioning NAPA Echlin as the premier aftermarket automotive brand.

I guess this is why I've always had such good luck with NAPA stuff.