Out of curiosity, have you checked the exhaust for leaks before or near the O2 sensor, and checked for power at the O2 sensor heater wire? (orange)

 

Zero. Really???The lowest I see on anything is like .5,.7, < .8 is not unusual for just my leads on my cheap-o- meters. You got a "nifty" meter? Maybe yours does something mine doesn't. You have it on the 200 ohm scale? It's not flashing a "1"?

Anyway, worthy of note. I've had my 02 fail, Ive unplugged my IAT, CTS, IAC, and TPS at one time or another. The only thing that really hammers it and ***** it up is unplugging the vacuum, or the wire plug to the MAP. The MAP rules, it seems with the mixture. Just my .02....I ran almost OK with the 02 doing nothing, (bad mileage, odd, cycleing idle).

 

Oh, howdy Radi...yea, I'm that slow!

 

Howdy Don, nice to see you!

What are you doing with all those meters anyway, lol. New one for each measurement?

 

32 years off the grid. Some over amped via hydro or solar. Some simply got wet tuning the hydro wheel. Some just got old. One strangely smells like beer.


That deal on the left is a mechanical RPM meter, circa Titanic days. Three small input shafts on the front for measuring different ranges.

 

I really don't have the time for it, but....has finely machined brass gears with a centrifugal wights, a heavy aluminum housing, three inputs to 500, 1000, and 5000 RPM. I got it partly free, now the bezel ring around the glass and I can get some Casrtol 30W in where it matters.

I'm not exactly sick, just I'm a Scott. Screw the mortgage. I gotta see the shafts turn and the gears engage, I'll get to to bills later...

 

That was actually next on my list since I bought the o2 sensor..Work is getting in my way unfortunately..

 

LOL! I've done so many tests now, they're running into each other.. I'll definitely do this one again.. I haven't had a chance to really inspect that tube from the TB to the MAP yet either.. If it's that little tube I'm going to be.... well, I don't know how I'd feel.. Happy that we found the problem more than anything, I'm sure! I'll keep you posted, thanks Don!

 

Aw Man! That thing crucial! If the MAP doesn't sense vacuum it thinks you have your foot in it and dumps fuel. It uses that to make a rough guess at how much gas the engine wants. THEN all the other stuff fine tunes it from there. That tube gets brittle and cracks or breaks clean off really easy when you are doing something else...Later 96-97? they moved the MAP to the TB.

 

X2
Awhile back my MAP tube broke off and it brought down my mpg to 4!
$1 for a foot of silicone vacuum tube fixed it. Needless to say, VERY crucial!!

 

"""""but I don't want it to be a coil!""""

Is that the reason you like to keep on having trouble?

 

I thought that was checked out long ago!! Not something to put low on the priority list.

 

Now that he knows what it ISN'T - what next? Wash behind the bumpers?

He said the coil and PCM were checked by autochina - they have no way to test a coil except by an Ohmmeter - and the burger flippers that work there won't know how to use it anyway. An Ohmmeter cannot test a coil for voltage breakdown. AND - They cannot test a PCM at all!

He said he's not getting a crispy blue spark - ANYTHING OTHER THAN CRISPY BLUE IS LOW VOLTAGE AND LOW CURRENT - NOT ENOUGH TO FIRE THE PLUGS PROPERLY.

Red, white, yellow, orange, blue - all show the voltage available, red being the lowest. Bright crispy blue shows about 28+ KV. Lower than that creates problems - to see what problems, simply read back through this thread.

It's not new or exclusive to JEEPS - that dates back to the first ignition system in the 1800's.


Even a cheapie Chinese knock-off coil from them will run better than it is. It will only last a short time, best to buy 2 or 3 coils.

A quality coil from a jeep dealer is probably about 15% more money - but will last years vs a few weeks.

Or - take it to a shop where they have and understand a scope - within 30 seconds the operator will say "bad coil." But t will probably cost at least $35 to hear that.

The PCM, does not/cannot limit the coil output voltage - it only provides an ON/OFF pulse.

The CPS is only the trigger for the PCM - it's either there or not.

The CPS IS NOT a HALL Effect device - it's simply a coil of wire wrapped around a magnet. Look up HALL EFFECT DEVICE on the internet - you'll see it's a semiconductor switch. It uses at least 3 wires. CPS has only 2.

The 5 volts to the CPS is simply a bias voltage.

Proximity to the flywheel is set by the predrilled mounting holes. Getting it too close may cause double triggering - another problem. Or when hot and things expand, it may hit the flywheel - destroying itself and possibly the flywheel's notches.

The quality CPS's come with a small cardboard sleeve for installation - to keep the spacing correct. I believe proper spacing is .006" - but it's near impossible to measure it because of where it is - that's why the cardboard sleeve - to make it foolproof!

Junk Chinese CPS's don't have the sleeve.

 

Yea??..I think it's easier to check than reading back through 100 posts! Also it might have been bumped, (or breathed on), while he was working on it!

 

I agree with everything posted here except the comment about CPS voltage. On a Renix, the AC voltage is generated by the CPS, not provided by another source.