Many problems from 90 XJ...

Okay... Quick story behind the cause...
new tires, new lift, big pond... drive it in pond never drove it out... water locked engine, water in everything... axels diffs tranny engine...

two months later now...

water is out of everything (except maybe the gas tank). Engine is back and does turn fine, new starter, strong alternator, new gaskets, new coil, new batt (red top 6 pack). I seem to not get any spark out of this new coil. volt meter shows it to work fine. got new plugs, wires, distributor cap n rotar... NO SPARK!

#2. Gastank... I'ma go ahead and syphon it empty... water in the fuel lines? if so do i jus turn it till its out? will it ruin injectors?

Finally, anything else you people recommend checking? Its really close to being up and going again... Can't wait...

we got some stuff at advance that removes water from fuel.

I just noticed you said it turns over, so hopefully nothing mechanical has been majorly screwed. No spark, well did the computer get wet? If so, pull it, open it up, run it under the faucet to wash out any contaminates, lay it in the sun and let it dry completely. You might want to pull the connector where the wiring harness goes though the firewall and dry it out. Also connector C101, the large one above the brake booster. These are the main junctions in the wiring harness. The CPS may be bad, but pull its connector, clean it and replug it.

No spark can generally be traced to 4 areas. Bad wiring/connector, bad cps, bad ecu, or bad coil. The camshaft position sensor will not keep you from getting at least a spark.

Good luck.

Okay, nothing is wrong w distributor, wires or plugs... i've traced the problem to the coil. its new but its not gettin any juice. contact are clean. starter silinoid works fin but i dont know what to look for b/w that n the coil. where does the coil recieve its juice from?! i'll be here waiting... -MOOSE

Okay, the ECU being underwater might have alot to do with it... What ayll think?! I need to get juice to the coil!!! What do I need to do?! -MOOSE

The thicker yellow wire to the ignition control module, is power in, key on. The thinner yellow wire is the trigger wire. The coil has constant voltage in and then triggers to ground through the EC to produce high voltage.
The larger yellow wire comes from the ignition switch, the smaller trigger wire goes through the ECU.
If you have power to the ICU (ignition control unit), the key to ICU circuit is good, the problem is most likely is in the ICU trigger wire, the CPS (which is the actual trigger) or the ECU.
Though one of these days, I´m gonna unplug the MAP and try to start mine. Or in other words and open sensor circuit, may also interfere with the trigger. Possible, even likely.
When you say coil, are you meaning the coil or the whole ignition control module and coil unit?
Also keep in mind, start and run are two different circuits. They switch at the stater relay and other places. No spark at start, doesn't necessarily mean no spark at run.
I've had problems before, with the first connector between the ICU and the ECU (C 103 connector) , with the large yellow wire, it was wet and leaked so much current that my spark was too weak to start the motor. Tested 12 (14) volts, but just didn't have the amps, with the starter turning, to produce a good spark. The ICU and coil, use a relatively large amount of juice.
Water in the connectors, is a common Malf, for people who like to play in the mud. Corrosion in the connectors is also a problem. A good contact cleaner and a very small scrub brush, works for me. WD-40 is not recommended for sensor or low voltage circuits.

Little known fact, distilled water is non-conductive you can clean electrial parts with it, just make sure it's dry before you power up.
The best mix is 10 to 1, 10 parts distilled water to 1 part isopropyl alcohol.

You might also want to test the ground for the ICU and coil unit, I haven't traced it out in awhile, but seem to remember it ends up at the dipstick holder (along with the TCU and others) after going through a splice.
Another trouble spot is the connector between the coil and the ICU. It sits in a cup and is pretty much open and fills up with mud and water.
I've found fluorocarbon (freon) based solvents to be the best for cleaning contacts, but they are out of production. Carbon tetrachloride (dry cleaning solvent) also works well, but is hard to find.

I got the ECU pulled out now... A lil corroded and dirty... no signs of electrical burn... Just outta curiosity, if i need to get a new one... how much am I looking to cough up for it... Also, I broke the radiator neck the other day... Any ideas on saving the radiator w/o getting a new one? Like jerry rig something to make a new neck... maybe some pvc pipe n JBweld?! lol... I'm cheap...I've done some reading about the cowl snorkel (air duct hose into the firewall) has anyone done this and how did you like it?!

I've had amazing luck with Loc Tite metal mender, with emergency radiator repairs. It has to be scratched up pretty good and really clean. Wouldn't count on it holding forever though, the epoxy glue and copper expand at different rates and it´s gonna fail again sometime.
Solder works if the radiator is copper (or brass), but it is really hard and takes some forethought. You get it hot enough to solder and the fins come unsolder-ed. I have some special goo that keeps the heat in one spot. A radiator shop that does radiator soldering all the time, could probably fix it quick and cheap. I've found a a soldering iron (the kind used for tin work), rather than a flame works best.

Would a solder for electronics work, like to solder wires and stuff...

Heres a link to some pics of my Jeep on it glorious death day...

http://www.naxja.org/forum/showthread.php?t=66386

I wanna retro my dash... remove it all and make custom dash w round gauges like an old CJ or Willy's... Would that not look pretty cool on a XJ?! 6 round gauges and a CD player. I dont need the air crap or clock... though an analog round clock would be also a cool add-on...

Anyway way to make ish simple and just now have a computer?! Like, just make it simple... str8 power to it nothing fancy?! Bypass computers n crap... Possible at all?! Smart or not?! This thing is gonna be offroad use only now so I dont really need it to be legal...

Before you cuss me out n make me sound dumb... I'm 20 years old, dunno crap about computers on a vehicle (but very handy w a PC) know basics on motors, rebuild and stuff... I'm very ignorant on vehicle electronics except stereos and stuff. So I'm learning as I try to get my old Jeep going again. So dont beat me up too bad...

They have irons, that you put in a fire to heat up, not really expensive. Plumbing solder and paste (the type with the solder already in the paste is best). The trick is not to heat and melt the good parts while you are trying to heat up the piece you want, enough to solder. Heat travels in copper and it gets hot a long ways from where you are heating. To tell you the truth it is really hard to do, without screwing up more than you fix.
I´d try to fix what I got, instead of yanking stuff out. You are gonna eventually need a defroster (I made that mistake).
I really doubt it's the computer. though bad ECU's happen, they are really pretty simple and bullet proof. It usually turns out to be something else.
I´m poor also, raised six kids, put two through the university. Have two living with me and partially support two more.
But All Data has helped me pick through the electrical on my XJ´s often, it cost a bit, but is worth it in time saved. They do a pretty good job of breaking it down into sub systems (bite sized pieces). A whole lot easier than a full vehicle schematic. They also, have tests for most all of the sensors.
The first time through, it´s a pain, it gets easier the more you work at it. Being twenty you should have an excess of energy, try it when your sixty or so.
Having said all that, I have an old pulse distributor, a Dodge ignition module, an ignition coil and a Ford two barreled carb. that worked just fine in my 4.2 YJ. It had three gauges, a master switch, a starter button and a small harness of wiring, to run the whole works. My fun in the mud Jeep.

8Mud said:

When you say coil, are you meaning the coil or the whole ignition control module and coil unit?

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If you haven't checked out ignition module (sits under coil), I'd definitly check that out.

Okay, here it is again... New starter, alternator, coil, battery, and I've cleaned the ignition module, and ecu... ignition module passed two test at different stores... ECU was cleaned and no signs of electrical burns or problems inside the ECU... Still no start... ideas anyone?! there is no spark gettin to the spark plugs...

Like Old Man said the CPS (crank position sensor), is a likely culprit. I pressure washed the top of the bell housing, after changing a valve cover gasket and my CPS was toast. The test is with an ohm meter, it should read 200 ohms +/- 75 ohms. Though mine did test good and was still toast.
Check the red wires going to your ECU, one is constant power from the battery (through a fusible link) the other is on when the ignition is in the on position.
I hate to swap out expensive parts and find out it´s a connector causing the problem. I've found and repaired continuity problems about 3-4 to one, over component/sensor changes. Mud and water gets in the connectors, corrodes and causes all sorts of mischief.
A while back when I seriously drowned my wifes 87, the starter relay was actually full of muddy water. The starter relay also sends a start signal to the ECU.
The only way I've had any success, is to pretty much systematically check everything. Starting with the easy/cheap stuff first. Connectors are always a good starting point.
Have you pulled any relays and unhooked the relay block and turned it over and looked underneath? Darned mud gets in everything.
Last question, do you have power to the large yellow wire (with the key on) that runs to the ignition module. You can test it with a twelve volt trouble light. If you have power there, the problem is most likely in the pulse (CPS) or related circuit. Or another sensor circuit, divide and conquer.

where is a CPS located and how much roughly is it?!

Looking TO the front of the Jeep from just in front of the bellhousing, you'll find it at the 11:00 position, held on by 2 bolts. Prices vary from $50-110. A search here will get you all the info you need.

Okay, CPS is off and I hooked up my ohm meter too it, i must be doing something wrong... no reading at all... can you explain what i need to do to test it please.

MOOSE16285 said:

Okay, CPS is off and I hooked up my ohm meter too it, i must be doing something wrong... no reading at all... can you explain what i need to do to test it please.

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You should read 200 Ohm's +/-75 between a-b if you don't get that you found your problem or your meters broke.

Spray something in the connector and make sure it´s clean. Turn your meter to ohms and stick the leads into the CPS end of the connector. The most common problem is a bad contact with the ohm meter leads, the second is the ohm meter is on the wrong scale and the CPS is reading out if the box for that scale (switch scales and check again). Or the battetries are dead or weak in the meter.
The most common fault for the CPS, is the wire is cooked and/or broken. Second is a dirty or faulty connector. I've never seen the CPS, itself have zero continuity (though anything is possible). I have had them test good and still be bad though.
The 200 ohm +/- 75 ohm standard, has such a wide range because the ohms change depending on how close the end of the CPS, is to metal (ferrous metal/something a magnet will stick to).