Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: JackstandJohnny on December 18, 2007, 01:29:42 PM
-
so, bought another ZJ today, and on my way home decided to take it to the car wash and clean off the crud. and of course when i was done, jeep wouldn't start. so heres whats going on. it cranks over fine, just doesn't want to catch and start. i did not wash the engine compartment. also replced distributor cap just incase. it was dry. when turn the key i can hear the fuel pump whirring in the trunk, and there is fuel in the fuel rails, or there is pressure in the rails. i knwo it is also getting air. plugs and wires also look relatively new also replaced 6months ago. also ran the codes and got a code 55. so heres where i'm sitting: engines cranking, its getting air, seems like its getting fuel, and spark i'm not 100% sure on as i haven't tested all the wires and plugs yet. keep in mind, it ran and started great all day, until i washed it, then it died. i want to know what the connection is dammit lol.
need to get this fixed. this is supposed to be my DD
thanks
John
-
CPS or coil.
Cracked coil + carwash (lots of humidity) = bad coil
I think your next door neighbour can give you a hand if need be.
-
If it's not the coil, PM me about replacing the capacitors in the PCM unit. I had to do this to my previous ZJ with the same issues as yours, and a new coil didn't do anything.
PM me, in case I miss it.
-
ok. checked for spark today, and nothing. so i'm leaning towards, ignition coil. might change it out this weekend. and if nothing, then dunl, perhaps its in the pcm. for sure i will PM you. thanks for the idea dunl.
haha, thanks ian!
-
It might also be the CPS. After three seconds if the PCM does not receive an input signal from Cam & Crank sensors, then the PCM will not allow the coil to fire or permit battery to the injectors
-
Sounds similar to a problem I had with my Cherokee. In the end it was my battery. Mine would turn over but not catch and when it did I had to keep it revving untill it warmed up a little. I thought I might have water in my tank or dirty fuel injectors. A lot of people did think it might be sparks coil rotor, all that stuff but I had just gotten a tune up replacing all that. In the end the battery completely gave out, (after my jeep got rained on all day), when I replaced it I haven't had the problem at all.
Battery was 8 years old.
Starts in the minus stupid now without a problem. And in the rain.
Good luck.
-
hmm, i checked teh battery today, and it was holding a charge of 12.5, so i think its ok.... as for my dilemma, update: pulled the ignition coil today, tested it with an ohmmeter and it was reading between 3 and 5, so i think the coil is fine. i'm now leaning towards crank position sensor... not looking forward to replacing that. anyone have any tips on how to do this with ease? any tips would be appreciated
-
I'll start looking for that link for the PCM capacitors.....had trouble finding it the other day.
-
Post #27, halfway down.
http://www.jeepforum.com/forum/showthread.php?t=463586&page=2
No pictures, but this is what a capacitor looks like in case you're not electronically minded....
(http://tbn0.google.com/images?q=tbn:b3tAJuzCsXpz5M:http://www.opamp-electronics.com/~opamp/catalog/images/100uF_16V_Radial_Electrolytic_Capacitor_003054-5.gif)
These are the ones you are looking for, go to an electronics shop and find them - that's the hardest part. 220uF 25V
I remember that it didn't matter which it was for one of the numbers.....the 25v I think....but hopefully an electrician can jump in here and confirm that.
Pull the PCM, dig in the gel, find the capacitors, remove and resolder.
Maybe do some searching around and see if you can find the thread with the pictures....there IS one out there somewhere. I'll keep looking too.
-
WOWZIES!!!
A few beer, and I rule!!!!
Here you go....pictures on second page.
http://www.jeepforum.com/forum/showthread.php?t=330109
Like they say, might not be your problem, but might fix it for you. I was thinking it was the CPS for me as well.....
-
that thread has a whole bunch of cool information. did you change out the capacitors, or did you bring it into a computer shop?
-
Took it out, heated up the capacitor arms on the board, and pulled them out a little bit on each side, back and forth, back and forth, until they were free. Then put new ones in and resoldered. Make sure you pay attention to which way is the positive side, and which is negative. Mark it down on paper - you'll regret it if you get all the way through only to find out they were backwards.
30 minute job if you have everything.
I don't do electronics, but it wasn't rocket science. Only thing I would do is find some way to resealup those capacitors...silicone or something, so water doesn't get in, which I didn't do.
cLAY - I MENTIONED THIS TO YOU WHEN YOU BOUGHT IT, BUT IT WOULD BE A GOOD THING TO REMIND YOU JUST IN CASE.....PULL THAT PCM AND RESEAL IT UP BEFORE YOU GO WADING WITH THE ZJ.
-
Ya thanks, I was running wiring on it last month and noticed it and it jogged my memory.
-
hmm, i checked teh battery today, and it was holding a charge of 12.5, so i think its ok.... as for my dilemma, update: pulled the ignition coil today, tested it with an ohmmeter and it was reading between 3 and 5, so i think the coil is fine. i'm now leaning towards crank position sensor... not looking forward to replacing that. anyone have any tips on how to do this with ease? any tips would be appreciated
It's actually prettyeasy...2 small (10mm?) bolts, one rubber cover and one electrical plug. It's just a little hard to get at....I did one on a XJ from under, tricky but not too bad unless you're a beefcake (big arms) and I reckon it could be acsessed from under the hood too, if you're a bit of a contortionist...I think it could be done in 15 minutes but 1 hr fer sure!
I have since started carrying a spareCPS on the trail....
-
haha, funny you say beefcake. i'm definitely not small. (300 lb aren't the most agile of people usually) so i'm jacking the front end up, gonna crawl under and just unbolt it, hopefully
-
well, replaced coil and cps sensor today (200 bucks in parts) and still not running. i'm out of ideas. my cheap jeep is no longer so cheap, and the Just Empty Every Pocket ideology is not helping much hahaha. SO pcm is in the process of getting pulled...
-
Atta boy. ;)
I can't help you much more than the link I sent you....hope it works for you. :)
-
well before i pull the PCM i thought i would run the codes one more time just to double check. glad i did. realized i wasn't reading the codes right. now i think i am. i got 12, 33, 54, 55. 33 is the AC relay, no biggie i know its out, and 54 reads no cam sensor input. so to put it bluntly, shoulda run the codes before i did the CPS and coil. will swap part out this week. hopefully i have my DD back
-
so, after calling around calgary today, I cannot seem to find a 'cam position sensor' in calgary. apparently the part doesn't exist. I called tower chrysler, and they don't have such a part, they have a similar part that fits in the distributor, and the only one they have stocked is in Milwaukee. so anyways, whe i pulled my codes last night, code 54 came up, this is what haynes reads "No camshaft signal detected during engine cranking. " so what does this mean? what part is that? if someone can guide me that'd be nice.
thanks!
JOhn
-
You are correct its in the bottom of the dist. One from a 4.0HO XJ should work as well. Try aftermarket, NAPA, Parts Source etc. Also try asking for a complete distrubutor. Too bad its not a V8 and you could borrow parts from. There's always pick a part as well, should have a few 4.0HO XJs.
-
nobody carries such a part in calgary apparently, this is what i'm told. guess i can just replace the distributor or hit up PNP, which is what ki'm going to do. this sucks
-
buy some 3/8 extensions about 1.5 or 2.0 feet of them and do it from under the jeep easy money ;)
-
Ive got a dizzy from a 4.0, you could grab it along with the Tcase! ;)
-
haha, funny you say beefcake. i'm definitely not small. (300 lb aren't the most agile of people usually) so i'm jacking the front end up, gonna crawl under and just unbolt it, hopefully
shouldn't a beefcake like u be able to just lift it without a jack?
j/k
-
jeep is running again. put a new cam sensor in. or as parts stores call it the pick up coil. don't know why haynes doesn't call it that. regardless, its running again. i'm happy bout that!
-
glad to hear it!
-
I know this is an old thread, but i am a new owner of an old jeep.... My 94 ZJ, with 5.2 is doing the long crank thing and rough until warm. I did the pump, tune up etc etc. so now i am down to the PCM capacitor job. Does anyone know a good computor guy in Calgary who has done/ will do this repair for me? I havent done the crank or cam position sensor yet but thoght the capacitor job is the way to go and would have to be done eventually regardless as its now 18 years old.
Thanks!
-
Don't know of anyone that can do the repair but there are lots of junk ZJs around, might what to just replace it. You'll need one from a 1993 or 1994. Hit up Pick a Part. Or put up an add in the wanted section here.
-
Thanks, i see that pick & pull has some zj inventory. My pcm was made ( is labelled) late 93. I thought i could get away with anything to 95 or early 96 with the similar pin conector arrangement but if your saying 93 or 94 only, thats where i will go.
Once i get one and have a spare on the bench, then i might take a crack at the capacitor job.
-
Also, i understand these old ones dont need to be flashed with my vin and milage.... Is that correct?
Thanks in advance.
-
Correct.