Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: dunl on February 19, 2007, 01:00:20 PM
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Okay, I can't get my 93 ZJ V8 to start. In the past two times this happened, it was the ignition coil, so I replaced it, and this time it wasn't the issue (no biggie, I now have an extra for when the POS goes the next time).
It's been sitting for several months (due to it not running), so I checked the Schraeder valve, and there was only a little pressure. Re-charged the battery, let it sit in the on position for a bit to get fuel up the lines, no start. Checked the Schrader, and lots of fuel seeped out - appears the pump is working. Opened the intake, put a little fuel down there, no start.
Where's my next check? CPS?
Thanks.
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If your getting no spark then it is likely the crank sensor. They aren't too expensive so if that doesn't fix the problem you at least have a spare. CPS's are common for going bad, and not just in jeeps. A bit of a pain to change on some jeeps. Also you did check all your fuses with a test light right? :)
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Okay, I can't get my 93 ZJ V8 to start. In the past two times this happened, it was the ignition coil, so I replaced it, and this time it wasn't the issue (no biggie, I now have an extra for when the POS goes the next time).
It's been sitting for several months (due to it not running), so I checked the Schraeder valve, and there was only a little pressure. Re-charged the battery, let it sit in the on position for a bit to get fuel up the lines, no start. Checked the Schrader, and lots of fuel seeped out - appears the pump is working. Opened the intake, put a little fuel down there, no start.
Where's my next check? CPS?
Thanks.
you really need to check your fuel pressure in a more accurate way. unless you have a minumum of 40 psi(i think) your injectors will not open. you will need a fuel pressure guage with a fitting to attach to your fuel rail.
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try dumping a cup full of fuel down the throttle body and see if it will start and run for a few seconds.
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Thanks Chris, I'll check into borrowing a fuel guage from AutoValue or PartSource this weekend.
A cup FULL of fuel???
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Is it trying to fire at all or just spinning? If its firing even a bit then its probably fuel related. If its spraying out of the schrader and not firing at all then I'd agree that its the CPS(or coil).
Good luck changing that @#$%@#$ thing. Its nearly impossible to get at on a V8 and isn't cheap either. Took me 2hrs, a whole wack of different adapters and extensions and by the time I was done my arms were all brsuised, scratched up, and bleeding. :evil:
And in the end it wasn't the CPS it was the coil! :cry:
If you own a V8 GC and are taking the tranny out or exhaust manifolds off do yourself a favour and change that little bugger. You'll be kicking yourself later if it goes.
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Maybe...............
http://www.jeepforum.com/forum/showthread.php?t=378178
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Thanks for all the tips guys, going to give it another shot today.
TroubleMaker, I did see some infor on those capacitors, but I couldn't find a write up, so thanks - that link is great. The ECU/PCM is on my morning table (wife is pleased I'm sure), and cracked open. Looks like one of the capacitors is leaking, so after my Timmy's I going replace them. Let you know how it works out. :)
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One question....two capacitors are the 220uf 25v, but one that I see is 400uf -isn't it supposed to be 220uf like the others?
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I changed two out of the three, left the 400uf one alone.....
And guess what fired right up? :D
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I changed two out of the three, left the 400uf one alone.....
And guess what fired right up? :D
Right on!
I think the caps are board version specific, diff boards have diff cap ratings. Looks like a good alternative to paying through the nose for a new PCM.
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Yup. From the price of a new PCM ($780), looks like I owe you a beer...or a case. :lol:
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And I just got home from Rocky with my wife, after the ZJ died on me again.
I'm guessing the capacitors are fixed, and something else short circuited. :evil:
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One of the local guys here had intermittent problems with his 5.2 Dakota. Spent a bunch of money at the dealer and they couldn't fix it. He finally pulled the PCM to engine harness and went through it, found some corroded splices & bad connections, resoldered and resealed it and it runs like new.