01 XJ died, won't start

GotWood

GotWood

Sayer of Fact
Joined
Jan 12, 2007
Location
Maiden, NC
Just picked up this 01 XJ with 88000 miles and drove it about 50 miles with no issues, a perfect surviver. Last week I was going to drive it to work, started it and walked back to the house to day good-by to the wife/kid and add i walked back to it it just shut off. It hasn't started since. I have fuel pressure but that is all I've checked so far.

I don't want to just start changing CPS and various parts blindly, I need a scan tool that will help diagnose these kind of issues.

Where should I start.
 
benXJ said:
When did it cut off? When you put it in gear? Does it just crank over with no start? Does it spit and sputter? Is it out of gas?
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I was walking to the garage as it was running. I never got to it when it shut off. Now it just spins over, no sign of spark.
 
Is it the crankshaft positioning sensor that goes bad and makes the XJ not start? It's some sensor that goes out and this happen, may not be that one but it's one of them. Easy fix
 
Jmccracken88 said:
Is it the crankshaft positioning sensor that goes bad and makes the XJ not start? It's some sensor that goes out and this happen, may not be that one but it's one of them. Easy fix
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Many times it is the CPS. I'll be replacing it with an extra i have to see what happens but i need to buy a good scanner that can help diagnose these kind of issues.
 
Doesn't have to throw a code, just look at engine RPM while cranking.

Sent from my Z750C using Tapatalk
 
You can take that PCM to a Jeep dealer and they can test it. We had same issues and replaced CPS, throttle body and the two sensors on it, some other sensors, fuel pump, etc lol. We swapped out our PCM eventually (with a junk yard part) and made progress but couldn't keep it running so kept chasing it. Finally borrowed a known good PCM and troubles were solved. We couldn't have our PCM tested due to year model but yours is newer and can be. It's hard not to chase and replace parts because if your results aren't clear you think it must be bad.
 
I had a similar problem on a 93 ZJ years ago, shut off on me going down road. Would turn over but not fire. Ended up being ignition coil. I found that out after replacing cps, plugs, wires, distributor. Not saying it's your cause but wouldn't hurt to rule it out
 
Sounds like CPS. Throttle sensor also, make sure that's clean. I haven't heard of a trend of CPU going bad when I was deep into the XJ's but it's possible. it's a single coil on rail design, not cheap to replace, but it 'can' start with the coil bad, just runs like a bad of ass. Unfortunately in the 90's they went to a non-adjustable TPS on the 4.0, the earlier ones you could set based on voltage (it's easy)
 
mysterync said:
That I know of, there isn't a pcm or engine computer that can't be tested in vehicle!

Sent from my SM-N910V using Tapatalk
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So what kind of scanner does a home mechanic need to get?
 
GotWood said:
So what kind of scanner does a home mechanic need to get?
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Snappy probably has some great used solus pro's for next to nothing. Really any scan tool with live data and some bidirectional controls fits the bill. Auto enginuity is a laptop based scan tool that has rave reviews, obd link *android based* also make a semi professional tool. A test light, a decent scan tool, a dvom and a few pressure gauges are primarily my go to tools daily. There are issues that can't be confirmed with out high end tools such as an oscilloscope but with the basics you can do a good bit of the work required to diagnose a modern automobile. I'd really recommend a load pro lead set for your dvom, it's really a time saver!
Once you have a tool, I don't mind a bit to help with a diagnosis. It's data -less guessing that drives me nuts lol.


Sent from my SM-N910V using Tapatalk
 
GotWood said:
So what kind of scanner does a home mechanic need to get?
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Test light, paper clip and a random DVOM will tell you a ton!
I'll be glad to walk you through some tests.

Do the gauges move when you turn the key on? Volts, fuel, etc. If not, the 5v reference circuit is FUBAR. If they move like they should, we can move on to verifying spark and fuel.

The CPS is an AC voltage generator. I'd have to see if it is making voltage as it cranks.

Is the connector end of the cam sensor (where the dizzy used to be) pointing to the firewall, with the connector parallel to the block? If not, the oil pump drive may have seized and killed the sync signal.

Also, check fuel pressure with a gauge.

Check those and post up. We have some members here that lime to help.you diagnose.
 
Jody Treadway said:
Test light, paper clip and a random DVOM will tell you a ton!
I'll be glad to walk you through some tests.

Do the gauges move when you turn the key on? Volts, fuel, etc. If not, the 5v reference circuit is FUBAR. If they move like they should, we can move on to verifying spark and fuel.

The CPS is an AC voltage generator. I'd have to see if it is making voltage as it cranks.

Is the connector end of the cam sensor (where the dizzy used to be) pointing to the firewall, with the connector parallel to the block? If not, the oil pump drive may have seized and killed the sync signal.

Also, check fuel pressure with a gauge.

Check those and post up. We have some members here that lime to help.you diagnose.
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Well it was the damn CPS like always! She's now for sale!

01 Jeep Cherokee XJ 2wd
 
Jmccracken88 said:
Why are you selling ? If it were 4wd I'd buy it from you
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I bought it to sell. Don't see low milage Cherokees very often and this makes a nice one. I will buy another one but I prefer one that is not in this good if shape.

And if you want it to be 4wd I'll convert it for a grand!
 
GotWood said:
I bought it to sell. Don't see low milage Cherokees very often and this makes a nice one. I will buy another one but I prefer one that is not in this good if shape.

And if you want it to be 4wd I'll convert it for a grand!
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Thats a darn good price for a 4wd conversion...
 
mysterync said:
That I know of, there isn't a pcm or engine computer that can't be tested in vehicle!

Sent from my SM-N910V using Tapatalk
Click to expand...
Passenger kick panel area I believe is the location. OBD II connector under the steering wheel?
 
ahh yes. been a while since I worked on the xj. I think the trans computer is in the passenger footwell area.
 
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