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Unread 07-06-2013, 12:41 PM   #16
ZeeJay1997
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1997 ZJ 
 
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Quote:
Originally Posted by dakimbrough View Post
jeepgrandcherokeepcm.com......Great website for PCM .
Our Location
4690 SW 83rd Terrace, Davie, FL 33328

Looks like they are trying to lose the rep they made under another name.

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Unread 07-06-2013, 02:06 PM   #17
MeanGreenZJ
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It's the 99+ model years that need VIN and PIN programming. You can get up and running with a just the VIN programmed. The PIN mismatch will trigger a silent DTC.


Quote:
Originally Posted by dellis View Post
If you note, my guidance on programming was softened (because I just didn't have any personal experience with it) ... but, I had felt it was fairly reliable since it was once posted by ratmonkey.
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Unread 07-06-2013, 06:11 PM   #18
Oldfrog
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Quote:
Originally Posted by ZeeJay1997 View Post
Our Location
4690 SW 83rd Terrace, Davie, FL 33328

Looks like they are trying to lose the rep they made under another name.
I hear you. Next time I'm in Florida, I might drop in on them. We need to have a little "chat"....up close and personal.

Word to the wise: Do NOT buy PCMS from anyone located in Florida.
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Words of wisdom, Posted by Zeejay:
"..it's not air, it is the opposite of air... suckage so to speak."

Stalling? Work through Zeejay's list
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Unread 07-07-2013, 10:02 AM   #19
coralman
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There was one in florida that gave decent service called SOLO, the WJ pcm went south when I changed spark plugs{ I don't know, I didn't take the negative off and must've bumped something removing the coil packs. I do from now on}. Its still in there. Guy was friendly, if not a bit disorganised. Do't even know if they are still around.
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Unread 07-09-2013, 01:51 PM   #20
reynoldsjp
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Well this is getting to the point of selling. Did fine first day. Stumbled once second. Drove two days 80 miles round trip to work no problems. Started out today died on the interstate. Pulled over and tried to restart nogo. Sat for about 5 mins started right up. Although now for the first time the check engine light is on. Also the ac kept switching from front to defrost on its own. any help ? thanks I leaning towards O2 sensor
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Unread 07-09-2013, 02:34 PM   #21
dellis
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Quote:
Originally Posted by reynoldsjp View Post
Well this is getting to the point of selling. Did fine first day. Stumbled once second. Drove two days 80 miles round trip to work no problems. Started out today died on the interstate. Pulled over and tried to restart nogo. Sat for about 5 mins started right up. Although now for the first time the check engine light is on. Also the ac kept switching from front to defrost on its own. any help ? thanks I leaning towards O2 sensor
Seriously doubt it is your O2 sensor. Why? Because an O2 sensor is not going to influence a no-start condition - the PCM does not use O2 information as it starts and within the first 30 seconds or so.

Be patient. There is a methodical way that you can diagnose your Jeep's problem that doesn't involve guessing, throwing parts at it, and then getting frustrated.

Step one is to read the codes from the PCM with an OBDII scanner and report them back. There's a lot of experience on here that can help you diagnose your real problem.
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Unread 07-10-2013, 03:30 AM   #22
Oldfrog
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AC going to defrost is a vacuum issue. Mine does the same thing, but only because I havent installed the check valve at the firewall. Let off the gas and I bet it goes back to the vents, doesnt it? If so...it's the check valve that's needed. About $5 or so.

As for the stalling.....there is a process involved to methodically track it down. I wish we could just go straight to the solution for you, but that's not possible. There are many things that can cause it...and most but not all are related to something not agreeing with the PCM....or vice versa. One possibility is that whatever caused it might have already done a number on the new ( used) PCM. Or......knowing the guys in Florida...they may have just sold you someone else's PCM after cleaning it up and putting some stickers on it. For now....go thru Zeejays list of 12 causes of stalling, one by one and see what you come up with.

Next time it stalls.....get out,, wiggle the PCM connectors and try to restart it. Do NOT give it any gas until AFTER it STARTS.

Load test your battery too. Humor me.
__________________
Cajun Recipes and Fishing tips

Words of wisdom, Posted by Zeejay:
"..it's not air, it is the opposite of air... suckage so to speak."

Stalling? Work through Zeejay's list
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Unread 07-10-2013, 03:52 AM   #23
ZeeJay1997
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OP, what all have you done to this vehicle? Your post starts out changing the PCM. I think i recall you having another post but sorry I dont have time right now to run it down and read it.

Read the code. Consider spread contacts on the PCM connectors.
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Unread 07-10-2013, 05:50 AM   #24
Uniblurb
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He's installed a new battery and reman PCM as far as I can tell Zee..

http://www.jeepforum.com/forum/f13/n...l#post15533364

Reynoldsjp, here's a similar scenario I went through with my 96 4.0. Couldn't figure out my stall/no-start problems and took it to the dealer when I didn't know any better. They replaced the PCM along with installing a new crank sensor. Used one of those high-quality reman PCM's out of Miami (ACR-All Computer Resources, sic). Ran good but in less than a year had the same old stall/no-start problems and it fried another PCM. Turns out the mechanic/dealer didn't clean the engine ground by the coil stud which grounds the PCM which is the reason it fried 2 PCM's. It should also be noted most all sensors are grounded through the PCM so if this engine ground is bad you're going to have problems. Thanks to ZeeJay for diagnosing this engine/PCM grounding problem!

I didn't trust the dealer anymore so contacted ACR directly and got another reman PCM under warranty. And this "lifetime warranty" only covers 1 free replacement PCM. Nice! Installed the PCM, after cleaning off the 3 engine grounds & body grounds, and believe I may have had to replace another OE/Mopar crank sensor too.

So check for codes but also clean off all your grounds! Also check your crank sensor using the below test (5.2 & 4.0) with a multimeter set to the lowest ohm setting. On the disconnected connector to the sensor itself place the black probe on the middle "B" pin (ground cavity) and red probe on the "C" pin (power). Any resistance at all and you have a bad sensor. Only go with a Mopar sensor if bad our you'll be sorry. Good luck!
crankshaft-positon-sensor-test-p.-8d-8-fsm.jpg

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-Stalling ZJ? 12 things to check before replacing a sensor; the Dirty Dozen
-Crankshaft position sensor multimeter test. & video of testing.
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Unread 07-10-2013, 07:32 AM   #25
dellis
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Quote:
Originally Posted by ZeeJay1997 View Post
OP, what all have you done to this vehicle? Your post starts out changing the PCM. I think i recall you having another post but sorry I dont have time right now to run it down and read it.
He came on here about a month ago with a stalling concern, and a suspicion that it might be the fuel pump - based on a grumbling noise from the rear, and the car started up after he thumped the tank with a mallet.

Of course, he then got some "no need to test, here's your problem, just do it" posts. Following these, he cleaned his IAC, replaced his battery and tightened connections. He may have done some other work. Ratmonkey and others were trying to get him to test his fuel system. He tested his fuel pressure while everything was working properly, but I don't believe he ever monitored the fuel pressure during a stall or no start (which, he really needed to do to properly eliminate the fuel system as a problem).

He then assumed his fuel pump/filter/regulator are OK. He said he was going to test the CKPS, but never reported the results. He also wiggled PCM connections & rapped on the PCM & backed the Torx screws out of the PCM (lol ... I still am amazed that this propagates) & cleaned and re-seated the PCM connectors & finally removed the covers from the PCM (I don't think he resoldered the connections, just took off the cover to look at it). When he put it back together, the Jeep wouldn't start.

(Unfortunately, he didn't do tests at this point to diagnose the problem. No starts are the best times to do diagnosis. He just assumed it was the PCM and then bought a PCM.)

This thread was started after he bought a replacement PCM ... and the stalls continue.

Through all this, he still hasn't done the simple tests to even know if it is a spark problem or fuel problem.

I can understand his frustration.
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Unread 07-10-2013, 11:06 AM   #26
reynoldsjp
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I am very appreciative of the help and advice I have recieved on this site. Wether it comes with condescending tone or not. Then people wonder why bad advice is taken versus good coated with sarcasm. Dellis is correct I have replaced the battery and cleaned my IAC. I started with random "hiccups" at any speed which gave way to random stalls. Never had issue of starting until the banged on gas tank day after no start from stall while driving. I am the sole provider of a family of six. My extra cash does not exist. So I fix as I go. I had the battery tested it was bad. Replaced it. I took the PCM apart to check out the connections and was told from pics posted it was fried. After I put it together it wouldnt start and had no spark. So I let it sit until I could afford a used PCM off Ebay. After putting it in everything was great for a day. I have never had the check engine light come on during a stall. This is the first time and now it is on. I assumed that maybe this was due to a bad O2 sensor in exhaust because I had to replace the muffler soon after purchase. I am fustrated, because I consider myself able to fix most problems I have encountered on my vehicles. I didnt test fuel pressure during no start because at the time my Jeep was starting. I am also in Va Dellis . Perhaps you could help me with those "simple" tests I am overlooking ? Thank you for your wisdom.
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Unread 07-10-2013, 04:33 PM   #27
ZeeJay1997
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hang in there dude. the CEL coming on after 2 start up cool downs is normal for some codes. leads me believe the PCM is probably good.

if you havent had time to read the dirty dozen, there's several items there that dont cost you anything but time. namely grounds, wiring, PDC, and reconditioning the pins on the pcm connectors.

we really need the code to diagnose any further. fiind a parts store to read it for you.
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Unread 07-10-2013, 04:54 PM   #28
dusterdude
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When my zj started acting up,i thought i had a fuel pump issue,after replacing the pump with a bosch off ebay(thanks uni).i still had stalling issues.i bought a mopar cps off the net and its been all good for a while now.i have also read on here,that the cps controls fuel pump voltage,bet the cps is your problem
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Unread 07-10-2013, 06:17 PM   #29
ZeeJay1997
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I had time to go back read all of your posts and see you have done some trouble shooting. do you have meter and know how to use it?

My theory: You most likely would have seen the the code before, but every time you had a stall with old PCM, it was resetting itself and dumping the volatile memory. This scenario became obvious during my time of woe when I was monitoring the stalls with a scanner attached. Every time it stalled, all the monitors would reset to incomplete.

Now that you have a good PCM, a monitor is coding something after two trips.

cps does not control the fuel pump voltage... it is for timing of spark and fuel. cps is suspect and needs to be checked as uni specified. Also clean the grounds on the block and fender.
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Unread 07-11-2013, 09:01 AM   #30
dellis
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Quote:
Originally Posted by reynoldsjp View Post
Perhaps you could help me with those "simple" tests I am overlooking ? Thank you for your wisdom.
After some thought, I needed to organize what I'm saying, and I'm doing so in the chart below that corresponds to a situation when the Jeep is stalling during highway speeds and idle, and it will have an occasional no-start situation.

There are three tests to be done in order: fuel pressure, ASD relay, and spark. Depending upon which of these if failing, it will then narrow down your problem and you can start focusing your testing on the second level.

See graphic below (it may have some errors ... but it is at least in the ballpark).



For example, I commonly see direction to replace the Crankshaft Sensor to solve a random stall problem ... and the owner does this only to discover that their problem continues to exist. But, if the owner had simply tested the output of their ASD relay during a stall/no-start, and they saw +12V, then they would know that the Crankshaft Sensor is not their problem. Why? Because the PCM will not activate the ASD relay unless it has a Crankshaft Sensor signal.
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