Jeep Enthusiast Forums banner

Emergency, vehicle won't start, need help!!!

1K views 20 replies 7 participants last post by  AlamoJeeper 
#1 ·
Hello everyone. My brother recently bought himself a 1997 Grand Cherokee. It ran good on when we went and looked at it. Drove it down the back alley and no problems. Started it and shut if off a couple of times and no problems. Drove it home (about 5km) with no issues either. Once we got it home, I took and changed the spark plugs to NGK copper's, replaced the cap and rotor and replaced the plug wires. Ever since then we have had nothing but problems with it stalling or not starting. Oh and he replaced the battery as well.

We got it to a shop, died over 6 times driving it there (about 10km). They took and fixed the pickup coil connector. They said it ran fine for them, no problems. My brother picked it up and drove it home and it died on him twice while pulling into the garage. Now this morning we can't get it to start at all. We took and replaced the coil and still no luck. I don't know what else to do. It will cost over $100 to get it towed to the shop and have them look at it since they didn't fix the problem. I tried wiggling the connectors and still nothing. While trying to get it to start, I did get a very loud bang out the exhaust, I'm guessing it was flooded.

The vehicle has 224,700 miles on it and is 2wd and automatic. Has power windows and power locks and air conditioning.

Any ideas of suggestions? It's suppose to get down to -20 to -30 in a couple days and he needs to get this thing running. Thank you for your help!
 
See less See more
#2 · (Edited)
I should also mention that if I hook my scanner up to the jeep I get a code for the primary ignition coil circuit, but I don't have a check engine light on when it actually does run. I tried deleting the code with the scanner but it says it can't connect so it can't delete the code.

*Update* I just took and pulled all the new plugs and they were wet, so I took and put the old ones back in since they were working.... Again, it didn't start, I tried 3 times. I pulled one of the plugs after and it was wet with fuel. So It looks like it is a spark issue.....
 
#4 ·
K, so I tried that although I couldn't get the wires out of the connector, I did use a flat driver and elongate them slightly, but alas still nothing. I pulled a spark plug again just to see and I am getting fuel, but no spark. It is just so frustrating because I've never had this problem with any vehicle I've bought or owned and done this general maintenance too..
 
#6 ·
ZeeJay1997 is one of the experts on this stuff. Listen to him. If when you get to test the CKP (Crank Position Sensor), and see the plug, if it looks new, you might be more than halfway there. Many times people put in aftermarket CKP's and have failures soon after. If it's the CKP, only use Mopar. They're more expensive, but you only want to do it once. I hope you get it worked out. ZJ's are great vehicles, but have their idiosyncrasies. Good luck.
 
#8 ·
OK, thanks for the suggestions. I'll take and try to check the crank sensor today. I really hope we can get it fixed as I think he likes this thing even though it is 2 wheel drive. It is in such good shape, no rust, as it was a US vehicle. I'm not too worried about such high mileage, although we probably wouldn't have bought it if I had known it was 360,000 KM's instead of 224,000. I've heard these are good engines and go a long time.

I'll let every one know what happens. Thanks for the help.
 
#10 ·
Don't know Zee but your real good dirty dozen thread looks pretty professional to me but written in layman's terms so you can understand it. ;)

Should we assume Johnny your 97 is the 4.0 rather than the 5.2 since saw no mention of engine size? Maybe the 97 2WD only came with the 4.0?

First thing I'd do is read through the 'grounds' section in the dirty dozen. Open that photo link of the tan/black PCM ground wire on one of the coil bracket studs. Clean that connection good and easiest to do from underneath. The PCM supplies grounds to all the engine compartment sensors. If that ground is bad it can take out your PCM and one of the first sensors to fail w/o a good ground is the crank sensor.

In addition to the 2 crank sensor tests Zee listed the below one is good checking for crank sensor signal. This is for a no-start condition only and best to use an analog volt meter.

http://troubleshootmyvehicle.com/jeep/4.0L/how-to-test-the-crank-sensor-1

Instead of messing with the injector harness just pull the fuel pump relay in the PDC for the test. And be sure and disconnect the coil wire.

While they mention in that test/link you can't test the crank sensor test for resistance I don't believe that. The resistance test Zee posted and in my signature came straight from the FSM. And every bad crank sensor I've had did have resistance between pins B & C when it should have none. Good luck.

PS. these ZJ engines don't like NGK copper plugs and run best on good old Champion copper plugs which are OE. This won't cause a no-start condition but it will just run better with Champions.
 
#11 ·
Good morning everyone. So I took and snapped a couple pictures for you to look at... I pulled the connector for the CPS apart and put it back together, thinking maybe a bad connection. Tried to turn it over, it started for about 10 seconds and then died. I had a look at the CPS from the driver side of the engine and it is looking quite clean, so I am guessing it has been replaced. Looking at the connector... the one from the harness is quite dirty but the one from the CPS is looking clean. I also double checked the plugs we had bought and they are Champion RC12LYC plugs. The ones that I reinstalled (the old ones) are Autolite double platinum.

Thank you guys for all the awesome help. Hopefully this is the problem. My brother is calling the shop tomorrow as they will have to either come here or have it towed to them since they charged us saying it was fixed but it isn't. Told him to have them replace the CPS with a Mopar branded one and to replace the plugs with the ones we bought.
 

Attachments

#14 ·
Your brother might be slightly better off getting the CKP (CPS to many.) himself and taking it to the mechanic. The way most mechanics mark up parts, he could end up paying $150+ for just the part. Either that or just grin and bear it. They are not cheap, but are the known way to go when your CKP fails.

Let us know once you've performed tests on the crank position sensor (CKP). Good luck.
 
#15 ·
Someone has been into the PCM wiring. The black connector back shell is missing. Someone probably pulled their hair out and sold it to your brother.

But the bright side is that the back shell being removed gives a good opportunity to back pin the contacts in order to read voltages. That's probably why it was removed.

Edit: A nut is missing from te coolant reservoir. Also a tell tale sign that the PCM has been the object of troubleshooting.
 
#16 ·
Real good eye PCM-Zee! ;)

I had noticed earlier it looks like somebody may have installed a new cam sensor since the wire looks new, as does the connector, with new zip ties on the harness. Either that or they removed the dirty convoluted tubing from the wire and wiped off the connector. Didn't mention it since the cam sensor controls fuel rather than spark like the crank sensor.

Also noticed it looks like the ground wire eyelet on the dip stick tube may be behind the bracket instead of usually under the nut in front. But can't really see it that well. I'd clean it anyhow since it may go into behind the dash as a cluster ground.
 
#17 ·
Sure seems like issues with the PCM if you cant clear the code.... Have you checked with another code reader?

While evidence indicates that someone has had issues before (wiring exposed as others have said) I would check out the ignition parts youve put on. See if the coil is getting power/putting out spark. If its not then I would suspect either bad wiring from the pcm to the coil, bad solder joint in the PCM, or bad coil driver in the PCM.

Shops are going to kill you on labor. It seems someone has just thrown parts at it hoping they would fix it but that gets $$. More so if youre paying a shop to throw parts at it.
 
#18 ·
Sorry about the delay in my response/update. My brother ended up having the shop tow it to them. It ran fine that first day, it actually started after the tow truck dropped it off. The next day it started acting up.

Turns out the ECM is on it's way out. Now he is waiting for them to get one. The shop said that there is only 1 available in Alberta so going to try looking elsewhere.

Once they get it replaced I will let you know if it works or not. Thank you everyone for your very helpful ideas and suggestions.
 
#19 ·
You or your brother should mention to that shop to be sure and clean the grounds; especially the tan/black wire PCM ground on one of the coil bracket studs. If it's oily/corroded it can take out a replacement PCM too and had that happened on my 96 4.0.

Hopefully that shop finds a good name brand reman PCM and not one of the outfits which don't reman them correctly.

I realize there's some pretty high duty fees/taxes in having US parts shipped into Canada. While it's best to buy a PCM/ECM from a store if they have to ship one in they may want to consider Rockauto. The 97 4.0 Fed emissions A1 Cardone PCM/ECM is $194 plus $90 for the core for total of $284 plus any shipping/duty fees. The core charge will be refunded once it's shipped back. You can enter in the Canadian delivery address on the RA site to see what shipping, duty fees and taxes are.

Discount code 5387936748131651 can be entered in the "How did you hear about us?" box at checkout for 5% off.

Would guess the shop may do what they want but it never hurts to give them input for a better job and to save some $.

Too bad there isn't a junk yard nearby and that PCM connector should have the cover on it that Zee noticed was missing. Would think a 96-98 ZJ connector cover would fit. Good luck!
 
#20 ·
*UPDATE* The shop got it running. Got a used computer for around $180 plus $50 shipping. I think he said total bill was around $500 with the computer/ship and they used 1/2 tank of his fuel. Told them to also clean the grounds and tan/black wire pcm ground. So far so good, doesn't seem to have anymore problems with it running.

He also was finally able to get his winter tires installed on it. Now just have to figure out why the interior lights stay on. I was looking in the fuse panel because the interior lights weren't working. Put a fuse in and then they just stayed on so I pulled the fuse again. Oh and I've also got to look into why the back window won't lock when the vehicle is locked.

Anyways, thank you everyone for all the help!
 
#21 ·
Glad to hear you got it running reliably. A genuine Factory Service Manual (FSM) is a great help in troubleshooting problems. I bought a paper one published by Chrysler for my 1995 Jeep on eBay.

I also bought an electronic copy from eBay that claimed to cover a broad range of years including 1995. I expected that when I downloaded it I would get an opportunity to specify which year I wanted. When I downloaded it, I had no opportunity to specify the year. What I got was obviously a 1998 manual. When I told the seller that it did not include aspects of my 1995 Jeep and made statements that only applied to 1998 models, he refunded my money.

Buyer beware. :)

Hope this helps.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top