97 TJ died and won't start

Phyrmon

Phyrmon

New Member
Joined
Mar 12, 2020
Messages
9
Location
Santa Paula, CA
Good afternoon all!

I am a new member, but my son and I have been haunting the forums for a few moths now, since he purchased a 1997 2.4l Wrangler.

One night we were driving to the store and he was struggling to maintain any speed. Said he “has it floored” and the Jeep barely chugged along. It stalled and he was able to start it and drive around the corner before it died again. Told it home and it started long enough to back into the driveway and that is the last time it has run.

It’s been to the mechanic, who involved two other shops for help, and everyone is at a loss. We loaded up the parts cannon, fired that bad boy, and loaded it up again. Still no joy. The engine cranks over and seems like it wants to catch, but t just won’t.

New fuel pump.
New computer
New distributor
New CPS
New wires
New fuel injectors
New coil
New pugs, they have been fouled twice since changing them.
Changed the engine grounds

Fuel lines are good.
Compression is good.
Fuel pressure is good.
It’s getting spark.

Checked the fuses and relays.
Timing system was checked and is okay.

Somewhere, about two months ago, I saw someone, somewhere mention that they found a plug (it was the big one near the computer on the firewall) that had gone bad. I can’t find that thread again. Does it sound familiar to anyone?

This is a hugely frustrating issue - but it’s been quite the eye opener for my son being a new Jeep owner. I’ve had a ‘74 Cj 5 and a ‘98 Wrangler) it was at the shop for 9 weeks and these are mechanics who I’ve used for 20 years that know what they are doing, not “my buddy who is a knowledgeable gear head”.

Thanks everyone.

Any thoughts?
 
This may seem basic, but have you checked all the power connections from the battery to fuse block to starter etc. for continuity? Also, is the battery fully charged and able to deliver the required CCA's to start the motor?

It sounds like just about everything to be done has been done. I'd imagine it'll be something so obvious that when you find it you won't believe it.

Best of luck!
 
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jesseshoots said:
This may seem basic, but have you checked all the power connections from the battery to fuse block to starter etc. for continuity? Also, is the battery fully charged and able to deliver the required CCA's to start the motor?

It sounds like just about everything to be done has been done. I'd imagine it'll be something so obvious that when you find it you won't believe it.

Best of luck!
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his engine cranks......
 
Buy a can of starting fluid. Remove the air intake tube at the throttle body. Have someone crank the engine over as you spray a small amount of fluid into the throttle body. If it runs on starting fluid, you have a fuel delivery issue. If it doesn’t, you have an ignition issue.
 
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Daryl said:
Buy a can of starting fluid. Remove the air intake tube at the throttle body. Have someone crank the engine over as you spray a small amount of fluid into the throttle body. If it runs on starting fluid, you have a fuel delivery issue. If it doesn’t, you have an ignition issue.
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Yes, ready been through all of that.

All three mechanics have said, “EVERYTHING says this engine should run.”
 
Imapepper said:
distributor 180 out? OEM replacement for electronics?
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Yes, to the OEM.

What do you mean by “distributor 180 out?”, I’m not familiar with what you’re asking. The mechanic did replace the distributor. He and the guys from the second shop collaborated on it together and tried several different things with the distributor before replacing it with a new one.
 
He means the distributor being installed incorrectly. You have to time it with other components when you replace them.

Did you use a MOPAR crank position sensor? I haven't had the problem myself (yet) but there are a TON of threads on here about bogus aftermarket CP sensors.
 
jesseshoots said:
This may seem basic, but have you checked all the power connections from the battery to fuse block to starter etc. for continuity? Also, is the battery fully charged and able to deliver the required CCA's to start the motor?

It sounds like just about everything to be done has been done. I'd imagine it'll be something so obvious that when you find it you won't believe it.

Best of luck!
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That’s what I’m thinking, which is why I mentioned that video I found about the guy replacing (actually jumped the wiring) the plug. It HAS to be something like that. Like I posted to someone else, all three of the mechanics who have worked on this are perplexed. Everything says this engine should run and no one can figure it out.

Would the O2 sensors prevent it from firing up?

I wonder if it’s probably worth replacing the engine completely, since he complains about the lack of power
 
qslim said:
He means the distributor being installed incorrectly. You have to time it with other components when you replace them.

Did you use a MOPAR crank position sensor? I haven't had the problem myself (yet) but there are a TON of threads on here about bogus aftermarket CP sensors.
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Yes, we were aware of the CPS issue. I’ve seen those threads too, so I brought it up with the exchange (also a Jeep owner) and he was aware.

I get what you’re saying about the distributor now, and yes, that was taken into consideration. Joe (the mechanic) explained that to me one of the days I stopped by and he was showing me what they were up to with the distributor)

This one is perplexing.
 
Phyrmon said:
Yes, ready been through all of that.

All three mechanics have said, “EVERYTHING says this engine should run.”
Click to expand...
I’m confused 🤷🏼‍♂️. It runs on starting fluid? I’m not talking about popping & backfiring, it runs good on starting fluid?
 
Hello again everyone! Here is the update.

My son and I started working backwards and going as deep as we could into the memory vault.

I remembered him telling me about a previous issue. Two days before driving home from college for Thanksgiving break, he was wheeling in a canyon and felt a “thunk” and the increased noise of a busted pipe. He found a slightly bigger than a golf ball sized hole in the pipe just before the catalytic converter. It was rusty but not really rotten. He took it to the muffler shop and they also diagnosed a clogged cat, so they installed a new one. My son picked it up and headed straight for home right from the shop, driving 10 hard hours with gnarly headwinds, where he noticed that he had even less power on climbs than normal for that little engine. He attributed the poor gas mileage and power to the wind, he really struggled and was exhausted when he got home. (Just like when i would drive my Cj5 home from Salt Lake while in college.)

Flash forward to now. One of the issues that came up between two of the shops that worked on it, was compression in number four cylinder. One shop had good compression, the other had none. The first shop checked it again and had none the second time they checked. The theory (without actually tearing things down again) was possible a bad valve seat.

My son and I theorized that fuel was escaping down the exhaust manifold and heating up the cat, which caused the original failure, which built up pressure and blew the hole in the rusty pipe. He then drove hard for 10 hours and severally damaged the new one until it finally quit altogether. When he returned to school after T-Day, I had him drive my truck back to Utah so I could work on his Jeep. I drove it to the stereo shop and to the high school a few times, otherwise it sat for four weeks. It broke down for good the first day he came back for Christmas break. We worked on it for a couple of weeks before giving up and havingIt towed to the shop.

So, my son just went out and loosened the exhaust manifold in order to create a gap and an exhaust leak. Sure enough it fired right up but it is missing.

It was a long shot and sounded pretty far fetched, but it answered every issue that he and I could both remember. Now we have to figure out what the true issue is in cylinder four so we can clear this problem up. And install another catalytic converter. First time it has run since right before Christmas.

Almost everyone I ran this theory by thought , “wellll.... it’s possible.... but not likely. But it’s worth 10 minutes, what can we lose at this point?”

Thanks for your help everyone. I’m glad we resolved it and wanted to share the weird experience. Of course it was weird, it is a Jeep after all...
 
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