ok, just starting this so its easier, got a 91 xj that i put in a 89 block, tranny and transfer case, changed the dist out to the 91, and the crank sensor, and also i changed the intake and exhaust. but now when i try to start it, it will turn over, but acts like it wants to start, but wont, i checked spark at the #1 plug and nothing, tonight i'll get out the maulti meter and do some test to see wuts up, hopefully a cheap fix, wuts the volts and amps supposed to be at the coil? thx guys, all your help is kool

 

bump, any one, i need help on this, i pulled the plug that goes into the coil and its sending 11.5 volts, but nothing outthe coil, so i'm gonna replace the coil and see if that helps. i notice when i turn it over, it'll turn over then it studer, like lights go dim and it misses a beat, so any help would be grand,thx

 

I read your thread But I got nothing to help ya out. sorry

I bet if you Search www.NAXJA.org you will find your answer that is the major XJ tech site.

HTH

 

battery voltage?
did you check the cps wiring connector?

 

The CPS wouldn't cause the No spark! You should have spark still if it was just the CPS

 

You said it acts like it wants to start but doesn't? It even spudders but dies? Sounds like she is out of time. Are the plug wires in the correct holes and in the correct order in the cap?

 

thats odd, my cps had a bad connection and no spark at all, i cleaned the connector and i had spark and she started. i thought thats how they worked,
my bad, disreguared what i said then, doooh i thought i knew somethin...

 

Hey I could be mistaken bad CPS's cause all kinds of weird problems. My understanding was that the CPS would fire the injectors once the RPM hit 300rpm.

Hey I am no Expert at all I just know when my CPS was bad I had spark and fuel just wouldnt start.

 

ok, so it has to be spinning at 300rpm, so if it isn't spinning that fast it wont start??? it sounds like it fires on 1 or 2 cylanders, but i put the key to ON and tested the conn at the coil, its sending 11.5 volts too the coil but w/o turning at over i get nothing out of the coil, wuts the correct way to test the coil out put, thanks guys

 

ok, doin a lil searching and i found this link, in this, wut does "flashing" mean?

 

Not exactly sure what you are talking about now

 

oh, wow duh, forgot to add the link wow, wut a day http://autorepair.about.com/library/a/1g/bl077g.htm lol, sorry

 

i nominate you to find out what the cps really does, i think that may help out alot more people than you and me
i'll search too. cause we have 2 different things that its done...

 

C.P.S. (Crankshaft Position Sensor)
(AKA: CKP and / or engine 'Speed Sensor' in some Daimler-Chrysler publications.)
Do Not Confuse this with the CAM Position Sensor located in the "distributor"! Make sure your counterdrone knows which one you are talking about!
See THIS LINK for Cam Position Sensor Information.

This is the BIG Kahuna of problems for people with no start, hard to start & stall out issues! You do NOT want to have this fail far from home, wheelin' alone, tools in the garage and no spare anyhow... heck, even if ya did have the tools, helpers and a spare it's a major pain to fix beside the trail! This thing is kinda like a serpentine belt; ya won't remember to replace it until it breaks! Unlike a serpentine belt, SOMETIMES.... just sometimes, ya can limp on home... maybe. The CPS should be a regular maintanence item for any Jeep owner but the change out interval is more likely related to heat & vibration rather than miles. If anyone knows the actual time interval recommended by the factory on these, please let me know and I'll amend this page.

CPS: You can check it's basic function but be aware that sometimes the darn things can be 'intermittant' but still read 'ok' when measured due to engine heat/temperature. Even so, these tests will show up a borderline CPS more often than not.

Check the connector first
If you've just stalled out with same symptoms... unplug the CPS & plug it back in. If your motor fires back up you might get off easy, but don't count on it lasting forever. I dunno what doing this accomplishes other than cleaning the connector contacts enough to let additional voltage through to the computer. If unplugging & replugging worked then unplug the connector again and clean those contacts off. Then apply some OX-GARD, or other electrical contact cleaner & protectant (dielectric grease).

There is a distinct possibility that you're not getting a signal due to a faulty connector itself as well. Some people have cured their CPS problems by simply cutting the connector out of the harness and SOLDERING the wires together (Use heat shrink or electrical tape around the wire, of course!) Other's have replaced the connector with a newer, waterproof version from an electrical or automotive supply store.

Test#1 - Get a volt/ohm meter and set it to read 0 - 500 ohms. Unplug the cps and measure across the CPS connector's A & B leads. Your meter should show a CPS resistance of between 125 - 275 ohms. If it's out of that range by much; replace it. (* - Note: HO engines are measured from the B & C connectors and should have near zero ohms.)

Test#2 - You'll need a friend to help ya with this one.
Set your volt/ohm meter to read 0 - 5 AC volts or the closest AC Volts scale your meter has to this range. Measure across the CPS leads for voltage generated as your friend cranks the engine. (The engine can't fire up without the CPS connected but watch for moving parts just the same!) The meter should show .5 - .8 VAC when cranking. (That's between 1/2 and 1 volt AC.) If it's below .5vac, replace it.

Desperate last ditch tip to get home or a few more miles from a failing CPS: - Other than the unplug/replug trick... MJR passed on a trick of using a flat bar and a hammer to 'adjust' the CPS by smacking the CPS bracket and forcing a weak CPS just a tad closer to the flywheel. This lets a weak CPS get a stronger pulse and hopefully generate enough voltage to feed a good signal to the computer again. WARNING! - If ya smack it too hard... it'll go in too far and the flywheel will eat the CPS! Start walking.

Either way, if it fails ANY of the tests... you should replace it and save your self some major pain later. If not, at least carry a spare CPS but be aware that it's a royal pain in the *** to change on a cold motor and ya really don't wanna do it at night, on the trail and with a hot motor if ya can help it!


Taken from this site

http://www.lunghd.com/Tech_Articles/...iagnostics.htm

 

so does that mean you dont have voltage or fuel? i hope your wrong and not me because if im wrong then i fixed a problem that i dont know how i fixed, which means there could still be a problem, doooohhhhhh....