258 knock sensor?

[Atla]

Just rebuilt my carb, went to figure out how everything hooked into it and noticed a broken red plug on the top of the manifold. See picture below(not mine).

http://www.jeepforum.com/forum/f8/would ... ndex2.html

Posting pics is hard on an iPad btw. It's the little red plug to the left of the carb in the picture.

From what I've read it has something to do with helping your rig automatically adjust your timing.

Is this thing needed? If so what's the item name for it so I can order a new one?

[Stuka]

Its only needed if you have ALL the smog stuff setup, and even then it doesn't do much.

Also, you can attach images pretty easily, or you can use tapatalk and then its really easy to attach images.

[Atla]

Most of the smog gear has been pulled off by the PO. What sort of plug can I use to fill it? Or should I just leave what is left? The whitish center part of the plug almost feels like paper when you press on it.

[tgreese]

Pretty sure it was Carnuck that posted a picture of this knock sensor in a thread recently.

The knock sensor is shown in the '83 supplement to the '82 TSM, starting on page 67. It's part to the CEC (computerized emission control) system, which appears to be new for 1983.

You'll have to see what kind of thread the device has before you can plug it. If you want to keep the CEC system, my guess is that it will not work well without the knock sensor. If the CEC defaults to "there's no knocking" without the sensor, you will be in danger of dmage from pre-ignition. If it defaults to "I hear knocking" then you will lose performance because the advance will always be retarded some.

[tgreese]

If you go to www.oljeep.com there is a parts book that covers the 1983 J-10. Look up the PN for the part you need and Google "Jeep <PN>".

[Atla]

I have a copy of the '82 manual printed out, but where is the '83 supplement at? I don't see it on OlJeep's site.

I'm trying to read more about this CEC system, I think a big chunk of it has been taken out by the PO. I don't know enough to pull the remainder with confidence, but vapor canister and such is long gone.

This website has been pretty good for simplifying it to dummy terms.
http://home.sprynet.com/~dale02/

The impression I have right now is since I'm running a MC 2150 instead of the Carter BBD electronic control - I can just ignore it. Because while I still have the Computer Box under the dash, It's no longer hooked to my carb for any computer determined adjustments.

So do I even need the computer box if it is no longer connected to the Carb?

[tgreese]

I have a copy of the '82 manual printed out, but where is the '83 supplement at? I don't see it on OlJeep's site.
...

You get it when you buy a paper copy of the complete manual. You get the vacuum diagrams and wiring diagrams too.

I'd say not, if you don't have the BBD any more.

[Atla]

Cut out the ECM, the more I dug around by the carb location I was finding handfuls of wires no longer connected to anything.

Started pulling out lots of wires, running up to a relay mounted on the passenger fender.

I hate wiring, following these around isn't fun. And trying to guess what you should keep and not keep is unnerving. I'm also going to be installing my HEI soon, so some of the wires that go to the Ignition Module, Coil, Distributor are going as well.

I have a feeling I'll be asking electrical questions when I'm done.

But to simplify things, since I didn't need the ECM to run the carb - ALL wires routed to it and the relay mounted on the fender are good to remove correct?

[tgreese]

An '83 wiring diagram is shown on the oljeep.com site under "electrical." These must come from the Haynes or Chiltons manual; the TSM format is different. You could look at the diagram for the wires you are removing, and decide if they will impact any other functions. I think your only alternative to analyzing the wiring diagram is to unplug or clip the wires you want to remove, and then check that you have not affected any functions that you want to keep. Once you have confirmed that disconnecting the wires has no ill effects, you can remove the wires from the Jeep.

[Stuka]

Cut out the ECM, the more I dug around by the carb location I was finding handfuls of wires no longer connected to anything.

Started pulling out lots of wires, running up to a relay mounted on the passenger fender.

I hate wiring, following these around isn't fun. And trying to guess what you should keep and not keep is unnerving. I'm also going to be installing my HEI soon, so some of the wires that go to the Ignition Module, Coil, Distributor are going as well.

I have a feeling I'll be asking electrical questions when I'm done.

But to simplify things, since I didn't need the ECM to run the carb - ALL wires routed to it and the relay mounted on the fender are good to remove correct?

I just pulled ALL the factory ignition and carb controls out of my J10, and now have an HEI. It was a HUGE amount of wires I had to pull from the loom.

But do not pull all of those out until you have the HEI in. As they two computers do talk to each other. Simpler to do it all at once.

[Atla]

I was just reading through thread Stuka, right now my rig is non-running and I'm actually in the middle of re-installing the carb. Had to look at some pictures to remember how everything hooked up.

I had maybe five or six different plugs unhooked and dangling behind the carb, the oxy sensor had already been disconnected as well. I already cut the ECM out and started pulling those unused plugs and wires. On mine they all run to a pair of yellow relays mounted near the battery.

I was thinking last night as I was chasing wires around, what you just stated, that I should go ahead and install the HEI. I had been putting it off until I had the 8mm wires, remote starter, timing light, etc. But since I've already started hacking into the wires - I think I'll go ahead and drop it in and hook up the start/on wire and pull the rest.

On your J10 did you use the red wire going to the two wire plug for your HEI? (Plug with red and white wire)



This is the link I was reading last night to see what needed to be removed for the HEI.

Here's the pic:



I'm thinking on this picture, the 'To Factory Wiring Harness' is the plug with the red wire I need to splice to use for the HEI?

[Stuka]

Yes, I used the red wire on the two plug connector for power to the HEI. Its the simplest way to get power to it.

[Atla]

Excellent, thank you,

[carnuck]

Knock sensor only works if you have the 3 connector ignition box. The motor may have been swapped if that 2 connector box is original. The red bit is basically a microphone designed to "hear" the notes of the engine pinging. They went away from that quickly because internal engine noise would trigger the early ones. Nothing like having a clicking lifter suddenly retard your timing 15 degrees! When they got to Renix EFI, the sensors improved considerably and were attached to the block instead of the intake.

IIRC, it's not screwed into the open intake so it can be removed without a vacuum or liquid leak. In fact, I vaguely recall grinding down the threaded bump on mine a looong time ago so it would pass visual emissions in Canada.