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Unread 03-02-2011, 09:24 AM   #46
JS97ZJ
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Quote:
Originally Posted by Dyn0mitemat View Post
I had the exact problems described in this thread in my 98 zj (3 plug pcm) and I pulled it apart with no luck. There was only one cap in it and it tested good.

Ended up replacing it and everythings been bliss since.
Did you re-solder the pins to the 4 connectors to the board?

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Unread 03-02-2011, 10:02 AM   #47
classicmetalman
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Quote:
Originally Posted by Dyn0mitemat View Post

Ended up replacing it and everythings been bliss since.
Did you replace the cap or the whole PCM?
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Originally Posted by murphydajeep View Post
I say you should still hit something just to let it know you mean business, or shake a hammer at it in a menacing fashion
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Unread 03-02-2011, 10:43 AM   #48
Dyn0mitemat
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Quote:
Originally Posted by JS97ZJ View Post
Did you re-solder the pins to the 4 connectors to the board?
No, everywhere I looked and asked they said it wasn't worth messing with the newer (98) 3 plug pcm's because there wasn't anything I could do to fix it.


Quote:
Originally Posted by classicmetalman View Post
Did you replace the cap or the whole PCM?
The pcm
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Unread 03-02-2011, 11:00 AM   #49
classicmetalman
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Thanks DynO,
Care to drop the name of the company you got your PCM from?
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93 Laredo 4.0
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Quote:
Originally Posted by murphydajeep View Post
I say you should still hit something just to let it know you mean business, or shake a hammer at it in a menacing fashion
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Unread 03-02-2011, 11:08 AM   #50
Dyn0mitemat
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Quote:
Originally Posted by classicmetalman View Post
Thanks DynO,
Care to drop the name of the company you got your PCM from?

http://cgi.ebay.com/ebaymotors/ws/eB...TQ:MOTORS:1123
Thats the auction I won. Had to send core back in, but it has lifetime warranty
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Unread 03-02-2011, 11:29 AM   #51
classicmetalman
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Quote:
Originally Posted by Dyn0mitemat View Post
http://cgi.ebay.com/ebaymotors/ws/eB...TQ:MOTORS:1123
Thats the auction I won. Had to send core back in, but it has lifetime warranty
Thank you. Glad you got your problem solved
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93 Laredo 4.0
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Quote:
Originally Posted by murphydajeep View Post
I say you should still hit something just to let it know you mean business, or shake a hammer at it in a menacing fashion
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Unread 03-02-2011, 11:36 AM   #52
Dyn0mitemat
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Yup, was a PITA trying to find out what it was though. Best part too was that I just bought the truck and drove it out of this guys driveway and about 2 hours later it dies and wouldn't start. Didn't have fuel, nothing back there, so I bought a fuel pump on the way home from work, and luckily figured I'd try to see if there was power back there for the pump, and saw it wasn't getting power.
Took the pump back...
I didn't know what to do at that point, I check fuses and wires etc, thinking something electrical went.
Decided to see if I was getting spark, and I wasn't getting that either. Decided it was the cps (crank position sensor).
Bought one of those, and when I was about to install it, it dawned on me that it couldn't be that, because it wouldn't cut fuel when you turn the key on (when it normally 'primes' the fuel pump). As even if the sensor was bad, when the engine is stopped (as in, before you turn the key to start, having it in the on position) it doesn't relay anything to the pcm anyway, so it wouldn't matter.

Decided to get pcm ordered.
Whats odd though, is it was on/off a few times. Twice it randomly started, we thought it was just a loose wire or connection somewhere from messing in the engine bay. It would run like a champ, and then come out of the store and it wouldn't start.
Put the new pcm in and she started right up though. No problems since
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Unread 03-05-2011, 10:55 AM   #53
Garryjav
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been over a year since i fixed mine with the radio shack parts and its stil working everyday
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Unread 03-05-2011, 07:05 PM   #54
neonhomer
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There has to be a way to dissolve that damn potting material. If I could get that stuff off, it would be easier to try to track down problems on the board. Most likely, a majority of all PCM failures are from a component failure, not a IC failure....
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Unread 03-05-2011, 10:54 PM   #55
JS97ZJ
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digelsil silicone remover

http://www.aircraftspruce.com/menus/...ners_zrpm.html
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Unread 03-18-2011, 01:34 AM   #56
austinaubinoe
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Ok Ive gotten to the point where I have cut away at the gel around the old Caps and where they are soldered to the board. I have the Radio Shack caps in hand. My question is, how do I determine which side is negative, and which is positive?
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Unread 03-18-2011, 05:59 AM   #57
greasefingers
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One of the two leads to the cap is longer. This is usually the positive.
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Unread 03-18-2011, 06:22 AM   #58
LagartoJuancho
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Polarity

Also, the caps have the polarity printed in their plastic sleeve. Usually a band of different color that runs through the cap and has either a bunch of dashes (indicating that side's lead is negative) or pluses.

Use what's printed on the cap to be replaced as reference (assuming you haven't pulled it out yet) and just stick the new cap in the same orientation.
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Unread 03-18-2011, 11:24 AM   #59
austinaubinoe
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Quote:
Originally Posted by LagartoJuancho View Post
Also, the caps have the polarity printed in their plastic sleeve. Usually a band of different color that runs through the cap and has either a bunch of dashes (indicating that side's lead is negative) or pluses.

Use what's printed on the cap to be replaced as reference (assuming you haven't pulled it out yet) and just stick the new cap in the same orientation.
Ok thanks! My OBD1 board is slightly different then the one originally pictured. It has a steel heat sink instead of an aluminum one.

I think I can figure out the +/- on the replacements, but is there any way to tell on the board if I have already pulled one out? If I have the board in one position, and lets say determine the left side of cap #1 is positive. Can I assume the 2 others are left side positive aswell???
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Unread 03-21-2011, 11:31 AM   #60
LagartoJuancho
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Quote:
Originally Posted by austinaubinoe View Post
Ok thanks! My OBD1 board is slightly different then the one originally pictured. It has a steel heat sink instead of an aluminum one.

I think I can figure out the +/- on the replacements, but is there any way to tell on the board if I have already pulled one out? If I have the board in one position, and lets say determine the left side of cap #1 is positive. Can I assume the 2 others are left side positive aswell???
Not really. You have to evaluate each cap you're replacing individually.
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