88 Renix 4.0 Ignition coil
 

Earlier I was out refreshing the connections on my ignition module thanks to a write up I found on here.
When I took off my coil I noticed that there is a spade connector on it in the middle, but it wasn't hooked up to anything, is there a wire that's supposed to be connected there? I've got one (forgot what color of wire it is) wire that looks like it should go there, anyone have any input on this?
Thanks for your help in advance!

Tach?

No. The three prong is to the ecu, two prong goes to the tach. The spade is not used.

Awesome, thank you! Though I was hoping that it might be the answer to my loss of power at about 22-2500 rpm (no tach so that's my closest guess)
I've already done the ground refresh, c101, added new/more grounds, new tps, plugs/wires/cap. This is my 2nd Renix XJ, and I had a lot more power in my old one with 80k more miles on it. I can't even spin the tires on this one.

Sounds like you have been doing your homework! I wanted to make sure you found this link, https://www.cherokeeforum.com/f51/he...ix-links-1397/, has sensor values. Also there in my signature is some of Cruiser 54's stuff.

I always check the CPS first. If you are standing there with a meter it literally only takes a minute. Mine died shortly after getting down to .3.

Anyway, I'd be sure the wiring down to the lower sensors is not chaffing or grounding. Mine dogged sort of like you are describing for me when I had wires rubbing on the heat shield.

Fuel filter? Pressure 31, 39 with the vacuum line off the regulator?

Added; Crisp blue spark?

Did you ever do the sensor ground test as outlined in my TPS instructions? If not, here it is:

Cruiser’s Renix Sensor Ground Test
Set your meter to measure Ohms. Be sure the key is in the OFF position. Using the positive (red) lead of your ohmmeter, probe the B terminal of the flat 3 wire connector of the TPS . The letters are embossed on the connector itself.
Touch the black lead of your meter to the negative battery post. Wiggle the wiring harness where it runs parallel to the valve cover and also near the MAP sensor mounted on the firewall. If you have an 87 or 88 with the C101 connector mounted on the firewall above the brake booster, wiggle it, too.
You want to see as close to 0 ohms of resistance as possible. And when wiggling the harnesses/connectors the resistance value should stay low. If there is a variance in the values when wiggling the wires, you have a poor crimp/connection in the wiring harness or a poor ground at the engine dipstick tube stud. On 87 and 88 models, you could have a poor connection at the C101 connector as well.
Revised 05/03/2012

@ DFlintsone: I will check the CPS after I finish my coffee here, I've been meaning to check it for the past few weeks but haven't actually done it. I checked most of my wiring when I did the intake/exhaust gasket (it's been doing this since coming back from camping last July) two months ago. But I will check it again when I test the CPS.
Will a failing CPS cause these symptoms? By the connector I'm going to say its the original 88.
Fuel filter was replaced last June, about 6k ago, I've been trying to get my hands on a fuel pressure gauge, Autozone wants $150 to rent one or 45 to buy a cheap one so I haven't gone for it yet.

@Cruiser: I did your complete write-up 3 weeks ago, including new heavy duty battery to block (2ga), battery to radiator support(4ga), block to firewall (4ga), Battery to TPS resistance reading is .6 ohms now that I've re-done the c101, It was 87 ohms before that.

Update: Just checked my CPS, at cold its putting out 189.6 ohms and .5 Vac which is believe is right in the acceptable range.

First! I can help with some basics, but when the going gets tough, I hope Cruiser and others will show up!

Since enough threads come back around to it even when the CPS didn't really sound like a suspect, and you can check it in the time it takes to tie your shoes, I like to start there. It seems like an old points condenser, always coming up with new tricks.

I have the same problem with testing fuel pressure. As a jack of all trades I probably have over 1000 tools, but not one that will screw on there. Could make one easy enough. I DID verify that getting fuel in a tire gauge ruins it though! I might just pull up to a shop bay before lunchtime and see if someone would do it for the price of a ham sandwich.

Besides checking that pressure, Did you adjust your TPS?? Spark is blue?
Also, I see posted that people have problems with the Platinum plugs. Champion coppers gapped at .035 seem to be all the rage! Anyway the gap get's larger over time, that seems to show up at idle first.

Yea, my gang of wires from the injectors down was routed funny and some were grounding and made it stutter and dog, even backfire out the intake, only after it warmed up. (mid RPM, it would always go like crazy if I punched it) I mention that again because I have to wonder if one of those sensors could be faulty and doing the same thing. I repaired the wireing without seeing which it was. (over a year ago):brickwall:

It was the coolant temp, knock or the 02 sensor though.

TPS is new, adjusted correctly to .83 it runs a heck of a lot better than with the old (original one).
Plugs are only about two months old, champ coppers gapped to .035
I checked over my wiring this morning, no rubs and everything is tight. I'm going to check my CTS later

what is your input voltage to the TPS?

I really don't know the bottom line here. One might think if it goes like a xxxxxxx ape floored, you could rule out fuel. On the other hand it dumps allot of fuel floored like that. While it's metering the pulse at mid RPM, low pressure might still show up there, but not at WOT...Just don't know.

When you changed your filter last June, did it make a difference? Was it clogged? If it WAS, could be you might somehow have some junk in your tank that mucked up the new one.

Just on GP, you did check that your MAP tube is OK. My brittle old thing about crumbled. (you can check the ground there, same as on the TPS, I believe)

That coolant temp sensor on the side of the block and the IAT on the intake have the same values at the same temps, might want to check them at the same time if you go there.

How's the idle, and is it steady?, Or seeking, going up and down a couple times a minute?

I'm pasting a thing on vacuum leaks. Actually I'm taking a can of fluid with me right now going to the store, my idle was a little high yesterday...

Vacuum leaks suck. I go around with short little shots of starting fluid, if you hit one the sound of the engine will change. Small little shots! You don't want that stuff to accumulate. It's a fire hazard, but It evaporates right away. Also with a tube, or a section of hose you can listen for it. Don't forget the lower O rings on the injectors need to seal as well. (uppers would leak fuel).
The manifold bolts have a habit of loosening, especially that rear one. On anything like that you never want to tighten only one. It can warp/bend, even crack things. If I found that any that where easy to reach where loose, I'd pull the air cleaner and tighten them all, starting in the middle and working out towards the ends. I go over about three times. It's a bear of a spot to get a torque wrench on them all. Just don't ape on it. If its firm and not turning, no point in going on to break it, a REAL *****. The rearmost bolt underneath takes a little doing, but it can be done with the right extension. For that very back one by the firewall I use way long extensions (18"), with a swivel at the socket. Anyway, that's a good thing to check on any old Jeep. :thumbup1:

Do the sensor ground test next.

@DFlintstone: I checked for vacuum leaks again and took out my MAP tube, all look perfect, re-torqued my manifold bolts down about a week ago.

@Cruiser: I checked my grounds again, getting a ohm reading of .3 on all sensor grounds so they are all good, I did a resistance reading on the Air temp sensor and its reading as open at both cold and mostly warmed up, am I doing this correctly? Would this cause it to run weird? Running it for about 5 min in an open garage and its definitely running rich
@jacbob: It's been about a week since I set the new sensor, but I believe the input voltage plugged in was 4.93v

Did you probe the two wires to the sensor? I just now checked mine, I got readings between 1 and 2K, at a range of temps between 195* and lets say 140*. I'm not sure if the impedance of the meter would matter here, I would think not. That said in the "lunget" they specify "low impedance", I'm just not sure they were right on that one. Does look like my IAT is done. (that's good news!)

If you were probing the two wires to the sensor, and showed "1." IE nothing, in any range, including the 2K range, I would suggest changing the IAT sensor.

Noticed you took a look Laredo....guess you would have spoke up if we were on the wrong track....

Took a pic of something else that seemed a little odd the other day also!