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1997 Jeep Grand Cherokee problems.....please help

by girayjr / May 25, 2007 7:50 AM PDT

I have a 1997 jeep cheroke lorado. Sometimes when I try to start the jeep it will start and then seconds cuts off. Other times I will start the jeep and it will start up then when I drive away for a short distance it will cut off. And sometimes when I try to start it it will act like it does not even want to start.

It has been doing this at least two or three times a week since about a month. When I took it to auto zone to get a diagnostic check, the code indicated that the ignition coil was bad. But It did the same thing last yr and the code read the same thing. So once we replaced the new coil last yr it did the same thing. So I wonder why is the computer pointing to the ignition coil and it has been replaced.

I have replaced the spark plugs, cables and distributor cap.

Please help me with this problem.

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by KeBo12 / May 26, 2007 1:42 AM PDT

might be fuel filter,the only problem with that is they only have one and it's in the gas tank

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1997 Jeep Grand Cherokee problems.....please help
by girayjr / May 26, 2007 1:54 AM PDT
In reply to: jeep

thanks, but i have replaced the fuel filter also.

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Here's my shot
by Andy77e / May 27, 2007 1:10 PM PDT

I owned the exact same car, same year, same model. Still hate it.

Anyway... Sometimes even if you replace the coil, it could still be the coil. You can check the coil with an ohm meter, sadly I don't have the specs with what you should read on hand.

Other than that, there's two possibilities. Bad Cam/Crank sensor. If either goes bad, it can confuse the PCM into thinking it's time to fire a spark plug when it isn't, which in turn makes the computer thing the coil or plug isn't fireing when it is, causing a coil failure. I do not know how you can check the sensor on your own.

The other is a bad PCM. One way to check is if you get the car running, you open the hood, and lightly... *LIGHTLY* tap the PCM with a hammer. If it starts screwing up or stalls out, your PCM is bad. DO NOT beat the crap out of your PCM with the hammer to check it. I got one back with hammer imprints all over it. Of course it didn't work.

Sadly, the answer you don't want to hear is this: Intermittent failures are the worst most horrid things. Your best bet is a dealership. If you take it to a independent shop, they might change 20 things and never fix the problem, yet charge you tons. And even a dealership might have a hard time nailing down the problem, but it's still your best shot.

If you are bent on trying to fix it yourself, go to a junk yard and get a Cam sensor, or crank sensor. I would not advise getting a junk yard PCM unless you know for sure it's the problem, or if it's dirt cheap. I mean way under $100.

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I'm having the same problem
by kandrew1961 / December 23, 2008 12:39 AM PST
In reply to: Here's my shot

It dies as I am going down the road. It sometimes backfires. It acts like it is not getting gas. I put it in Neutral and coast . After about 30 sec or less it will start. I have replacen the crankangle sensor,Temp Sensor,Fuel Pump and filter,MAP sensor, Ignition Coil twice. Did a complete tune up. Still does the same thing. Sometimes I can gor for weeks and not have This problem problem.

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My fix
by redraider10 / December 24, 2008 2:17 AM PST

I had the same problem on my 5.2 97 JGC Lim and had a hard time but here is what I did. Also I only noticed this problem when it got below 40F. I first pulled off the Throttle body and cleaned it all out. I cleaned the IAC Idle Air Control Sensor put it all back together and it worked at first for a few months. I started to have the stall problem later on and just bought the new $30 IAC and the car has been running problem free, i guess, since then. Good Luck.

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Might be the PCM
by JGC-GTA / March 11, 2009 9:43 AM PDT
In reply to: My fix

Got my 97 JGC checked today after having the same problems for the last 2 weeks. Dealer nailed it down to PCM and will be $900+ for parts(special order at a Jeep dealer??)/labor.

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same problem
by mikeland357 / October 31, 2010 11:52 AM PDT
In reply to: Might be the PCM

I have a 97 JGC w/ the same problem. It happened a bout 3 months ago and I did a complete tune up: plugs, plug wires, dist. cap, rotor button, and cleaned the throttle body really well. No problems since until last week, now it is doing it again. I replaced the coil and it did not help. I can disconnect the battery for a few hours and it will run good for a while but the problem returns. I understand that Jeep recalled the PCMs to be re-programmed about 2 years ago. So that is my next step, to find out if the previous owner took it in the recall service. By the way, a new PCM is $178 at AutoZone or Advance Auto.

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by 97jeep / October 31, 2010 8:02 PM PDT
In reply to: same problem

I just replaced the pcm, yesterday evening. did not get to drive enough yet to say it worked, because some days my jeep runs fine, some it dont. I had no idea they done a recall on reprogramming these. I went to their web site and you can put in your vin# and it tells you if you have any recalls on your jeep, mine had a floor shifter recall but pcm did not come up.

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PCM update
by mikeland357 / October 31, 2010 10:38 PM PDT
In reply to: pcm

Well I called the Jeep dealer and they said there is not a recall on the PCM. They also said if it were the PCM that the check engine light would be on. Mine is not on. Anyone else have a PCM problem w/o the check engine light coming on?
They said about the only things that would cause the stalling out w/o the CE light would be one of three sensors (cam/crank or ??? -forgot the name he mentioned). He claimed they could run diagnostics to pinpoint it so I may roll the dice let them check it.

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Check engine light?
by mikeland357 / November 1, 2010 12:12 AM PDT
In reply to: pcm

Was your check engine light on prior to replacing the PCM?

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dont go to the dealership
by 97jeep / November 2, 2010 1:28 PM PDT
In reply to: Check engine light?

My first bit of advise would be to not listen to anything the dealship has to say. I dont think they can even know what the pcm does. I had one dealership tell me that the pcm had nothing to do with any of the problems i was having. But no, My check engine light did not come on until 3 to 4 months after my problem started, and it did not stay on. And their diagnostics are just as crappy as their pcms. They will tell you it is the coil, crank shaft sensor, distributor, rotary, and the list will go on and on, as will the bill. The best advice i got was from these forums. check out the other threads, read them and just go ahead and change the pcm and o2 sensor. it will save you hundreds of dollars in useless repairs and tons of time. and dont spend hundreds on a mechanic to do it for you. on the other thread that has over 600 post you can find how to change it your self, it is simple and easy to do. I done mine myself and know absolutely nothing about vehicles. i could not change my own oil if i had to, but i changed the pcm all by my lonesome self going by the advice of people on here. Much more than i got from the dealership or any mechanic.

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I did not take the dealership advice and I agree:stay away!
by mikeland357 / November 3, 2010 2:37 AM PDT

I did take my jeep to the dealership yesterday. They wanted to sell me a $660 fuel pump and 2.5 hours of labor. OMG, are you kidding me? (It's between $100 and $150 after-market). Per my insistance, they supposedly checked the fuel pressure and it was low. (don't ya think a clogged fuel filter might casue that instead of a bad pump?) They also had the nerve to tell me the Crank sensor should be replaced even though their own diagnostics said it was OK. I would not allow them to replace anything. Paid them $85 for nothing and left. Get this: they actually told me that the service tech tapped on the gas tank when it was running rough and it started running better thus their reasoning for trying to screw me out of $1,000. I brought it home and backed out the 2 torx screws mentioned in earlier posts and added a bottle of Lucas Complete Fuel System treatment ($10). Not sure which one did it but I have driven a lot the last two days and so far so good.

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Be careful of just backing out screws!!!
by jsadamson / November 12, 2010 8:41 AM PST

I have backed out the screws and my JGC ran great and trouble free for months. Then the issue started back in. Be sure to actually replace those screws with shorter ones. I think with mine just backed out something rattles loose and now I have the same problem and I took the screws completely out. I will check to see if I am recalled but if not, it looks as though I will just go purchase a new PCM from Autozone.

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new pcm
by 97jeep / November 14, 2010 8:23 PM PST

thats exactly what i have done, went to autozone, got another pcm, took about 15 mins to change them out and now my jeep runs great. except it has hard time starting. takes it a few seconds to turn over.

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same problem
by heapjeep / November 19, 2015 3:56 PM PST
In reply to: same problem

I have been through it with this jeep I have checked repaired all things possible hrs of youtube videos. a dodge mechanic said press on the middle plug that plugs into the pcm if it dies that's the problem. I did and it died, so the real problem is they don't make those plugs and to fix it you have to cut into the wire harness..sketchy the issue is so common with the 97 grand apperantly the plug breaks inside and the current doesn't connect I tried dielectrical grease zip ties they would work for a week or so.i know this post is old but maybe this can help someone save a few dollars fixing a phantom problem. im worried about buying a used plug parts for all I know that's why that rig is in the junk yard.. gggrrr I love my jeeps but this year is a piece of poo good luck to ya all

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1997 Jeep problems
by kelso99 / March 3, 2011 9:46 AM PST

I have been experiencing same problems. Going down the road, die sometimes 3-5 sec. then fire back up, sometimes backfire sometimes not. Sometimes in morning turn over but wont start, come home from work and will start right up. Replaced o2 sensor,crank sensor, coil,pick-up in distributor. Been thru most wiring harness under hood for broken wire,nothing found. Hard wired from battery to coil, still same problems. Unplugged pcm terminals no arking on posts. While running wiggled pcm terminals ,tapped with hammer, no problem. No consistency, weather,outside temp.,length of driving. Can anyone help? 1997 JEEP GRAND CHEROKE 6 cyl. 4wd

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1997 jeep problems
by heapjeep / November 19, 2015 4:05 PM PST
In reply to: 1997 Jeep problems

the female plug ends that plug to the pcm are famous for breaking on the inside making the jeep stall and all the problems I have read on here electrical grease and well placed zip ties is a good fix until you can round up the plugs.they don't make them any more, good luck

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I'll join the club
by mctrog007 / November 18, 2010 3:11 AM PST

I have the same problem, replaced the crank sensor numerous times, coil twice, spark plugs and cales. took it in to the shop and they also replaced the pcm, discovered a bad connector and rebuilt it. I'll have to ask them about the screws though. They may already have tried it. They are a great shop

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by mctrog007 / November 18, 2010 3:20 AM PST

what did the auto zone PCM cost. the one I go to is either tired of seeing me or happy to see their best customer. Depends on whose got the counter at the time. I should probably buy stock.

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Autozone PCM
by jsadamson / November 18, 2010 10:49 AM PST
In reply to: $$$

As much as I love Autozone, I would not recommend purchasing their PCM's. I have done a lot of research on this problem as my JGC is a secondary car and I have the time to do so. What I have found out is people who get them from the dealership or parts store have limited luck with how long it solves the problem. There have been some reviews of people who have purchased it from a company called Auto Computer Exchange. Google it or they also have an Ebay store. So far it seems they offer a fully rebuilt PCM instead of a remanufactured PCM. The difference is a rebuilt unit has all new internal guts while a reman unit only has new parts that didnt pass inspection. This means its still half old and could cause problems. Based on peoples experiences these problems do happen within about a 6 month or less time frame. The Auto Computer Exchange also offers a 14 day refund and 1 year warranty. I am purchasing mine in the next day or so and will write my results on this forum and the others I have been following. Best of Luck!!

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by 97jeep / November 18, 2010 1:31 PM PST
In reply to: $$$

i got mine at autozone, it was $200 with an $85 core charge. so far no probs yet. but its only been 3 wks. have u checked out the other thread on here, has like over 300 post on this problem? has lots of great info.

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same here
by cmalone12 / January 15, 2011 7:12 AM PST

I have replaced the crank sensor, fuel pump, ignition coil, o2 sensor, ignition switch, distributor cap, and pcm and it is still dying on me. And backfiring. I have no idea what else to do!!! Anybody have any suggestions?

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Possible PCM connection fault
by dlj727 / March 3, 2011 5:23 AM PST

I just worked on a 97 JGC with similiar problem and found the information here to be very useful.
The vehicle I was working on was difficult to start and would die after a few minutes. I checked the PCM connecters and found them to be poorly designed. The harness is heavy and puts a lot of strain on the connecters. I decided to try a cheap fix first. I wrapped long cable ties around the PCM and over the connecters going top to bottom. This secured the connecters and kept the harness from dragging the connecters down and causing bad connections. I don't know how well this will work yet but the vehicle I was working on seemed to run smoother, start easier and run longer. I'm unable to follow up on this possible fix as the vehicle belongs to a dealer. This may work if the PCM and the connecters are still in workable condition. Otherwise you will need to replace some parts. The reason this problem doesn't turn the service engine light on in some cases is that the loose connections may be cutting power to the PCM as if the key was turned off. I hope this works and saves you some money and aggravation. Be sure to use good quality cable ties at least 1/4" wide and pull then tight. Good Luck

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1997 grand cherokee laredo
by calicedemel / November 17, 2011 12:27 PM PST

Hey girayjr. I've had the same problem as you with my 1997 jeep for a couple weeks and a mechanic said should be a major problem with the eletric system. Today the car just died and a friend of mine helped me out easely. He trashed the conectors at the battery, Put new ones, that comes a single unit per package, not a set of two, because the single ones are bigger, clean up the wires and that was it. The car is running soft and normal, as never had been in trouble and the problem was the conectors at the battery, was lose and I couldn't find it, either the mechanic. With less then 15 dollars everything is fine. Why don't you give a tray? I have had many problems but I love my jeep and I don't wanna give up on it, we are so brave. Wish you luck!
Sandra, Orlando-FL

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1997 jeep grand cherokee has burnt through 3 PCM
by bowgal705 / December 10, 2011 12:26 PM PST

I have a 1997 jeep grand Cherokee that burnt through 3 PCM within 7000 miles total unfortunately only one was under warranty. Jeep has a copilot they can put on your car to diagnose the PCM problem. But are now denying they own them.
Chrysler needs their rears sued off. Jeep only has 110,000 miles.
Problem is when the PCM blows it gives false readings like o2 sensors, coils etc and you spend a fortune chasing it down.

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97 JGCL mystery problem
by thrillkillful / January 27, 2013 10:12 PM PST

I found that the pin connections on the pcm are a design flaw simply tie strap the square plugs to the pcm as tight as possible as not to get the wires in the way. I promise i have been fighting these symptoms for a year, and now i can not replicate the problem. .54 cents my brothers. you might want to use a strap gun as they need to be very tight. hope the best for yall.

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