Hello all-

2001 Cherokee Sport (it's super tight, Black ext.w tan and black interior, gray seats) (Super tight) (also have the 10 hole wheels, I've only seen one other Cherokee in Atlanta with these shoes)

Initially I had a crank/no start/occasional start/backfire through intake/loss of power/bad shifting issue which I resolved with some help. the issue was handled by replacing my fuel pump. There was a loud roar coming from the intake, which made me think there was a vacuum leak somewhere.

i checked my spark plugs, regapped then back to .035

I checked my injectors which are upgrades (4-hole) that I bought from a guy on these forums, don't remember the name.. Something with a J.. Anyhow there was no leak on them, o rings looked good as well. No fuel leaking anywhere in ignition systems. If you want injectors, message that man. (I'll edit this later to include his name). Cost me about $100... Worth it!!

I tested spark, air, and fuel... Starter is good, no visible vacuum leak, that left fuel... Unfortunately there's no code for fuel pump so it took me a minute to figure it out. Ultimately we sprayed some non-chlorinated brake free all around the engine bay with it running and the only change in idle happened after spraying directly into intake. Idle returned to normal and the noise subsided. Once we replaced the pump I was able to hear the pump priming upon KOEO. (Video attached for noise reference)(maybe not because my phone is a total proletariat with it's .mp4 that I cannot upload it to this .mov pleeb forum)

I unnecessarily replaced my TPS as initial research steered me in that direction. The Jeep threw the TPS code but probably because I was messing with it. it's almost a 20 year old car. I'm not worried about losing money on a new sensor here.

I cleaned the TB and replaced the gasket as well. Gasket was fish food (flakes).

So the Jeep runs now but I still have several codes

P1491 - radiator fan circuit
P0443 - EVAP solenoid circuit
P0130 - b1/s1
P0136 - b1/s2
P0705 - transmission range sensor

P1491 - the harness side connector for the fan looked a little blown like some fluid got in it so I replaced it with a spare, I spliced a new plug on it. I know it is regulated by temperature on the 2001 so it is rather difficult to troubleshoot for me. Fuses are good. (Try googling 2001 xj and see how often you actually get info on the 01, &#128514 I know 97-01 are similar but in 00 and 01 they got antsy and made changes...

P0443- solenoid circuit... Fuses all look good. No visible chaffing around the Purge canister... Kind of stumped here.

P0130- B1/S1 o2 sensor- from what I understand of o2 sensors they simply read data and help make compensations to the performance based on data they read.
P0136- B1/S2 o2 sensor- same deal, I'm not going to rush to replace these yet because I believe they are just reading some bad data... I don't need to get emissions done until June so if I have to by then I will replace them.

P0705- Transmission Range Sensor - I looked at the NSS/TRS plug, the gray one next to transmission dip stick... Plug looks good... Again no fuses looking bad.

These are all related in some way by relays or fuses...

I am having a hard time understanding how relays work or how to test them. And why so many things are bundled together like that. My knowledge of cars is limited to the work I've done on this particular vehicle. Electrical Gremlins and old cars go together like love and marriage... Interpret that how you will.

Today (2-14-20) I cleared codes again, and got 2 new ones n addition for a total of 7 codes.

P1492- ambient batt temp too high (I'm working in the sun, and had everything unplugged from pcm, not worried about this one)
P1698- no bus. I had something unplugged from pcm. No problem there.

So as it stands I have 4 incomplete monitors:
EVAP, O2 sensor, O2 heater, catalyst. I'm going to take a drive right now with codes cleared and begin a new drive cycle. It won't finish until a cold start and some extra miles happens tomorrow but I'm guessing the 4 EVAP codes will come back rather quickly.

I have looked around this forum and others trying to figure this out, but unfortunately all the threads with this issue never get finished. They just end. I did see one thread that was completed but I don't remember where I found it, ain't that some ****? Hopefully this can be a great thread for future car morons like me who kind of know a little bit yet definitely do not know a damn thing 😂

Any help is appreciated. Thank you for taking the time to read this. I plan on finishing this thread through with answers and solutions when they arrive, and how I got there.

​​​​​​2001 Cherokee Sport (Super Tight edition)

 

Have you checked the plugs at the computer ? are they clean and tight ? are all the ground wires clean and tight ? I found if you checked the o2s and the solenoid are ok then you might have a bad computer .

 

Yes the plugs and grounds are good to go.

I'm currently finishing the latest drive cycle so the codes are not back yet. The reason I thought these codes we're actually a problem is that they kept coming back immediately, even after I cleared codes, when I started the vehicle. Different codes would show up here and there but the only consistent ones were the EVAP codes.

What I think is happening is that the cat wasn't all the way clear so the data was bad. Now that I have gotten the codes to not come back immediately, I decided it was a good time to begin drive cycle. The Jeep is running great, as great as an old car can.

So far so good today, but it's possible the cycle isn't 100% complete and the monitors are incomplete as of yet.

I will reply again if the codes come back. If they don't I will still reply and discuss what I think the solution.

Thanks for your response

 

Jhc7339 is who I bought my 4-hole injectors from.

My Jeep is running as great as it ever was. The Delphi pump I put in seems to be working fine.

I was able to clear the codes and keep them off. As I thought.. They were fall out from the fuel pump issue.

I have 6 monitors complete, 1 incomplete: EVAP.
next up is checking the fuel lines running to the tank and the rubber hoses on side of gas tank to ensure they are not leaking after reinstalling fuel tank.
Maybe a new gas cap is in order

I only have to pass 7 out of 8 monitors in GA. My reader only reads 7 codes (it's a simple MATCO reader I stole/borrowed from a friend). Interesting! But I don't need to pass until June so there's time.

Just recently popped my favorite code p0303 (not related to thread topic issue). Maybe cylinder 3 plug has blown it's gap back after I regapped them all to .35.
I can this code my favorite because it's literally always on, poor cylinder 3 riding hot.

 

Check the battery temperature sensor. If this isn’t feeding a temperature (resistance( range, the monitors will not run. If you never knew this you would likely find out as you say, at inspection. They will go incomplete whenever you disconnect the battery, or clear the codes.
The transmission range code is for the NSS. Most likely the nss is bad. , and boy can they be a royal pain, Just did mine on another thread :NSS Nightmare Safety Switch"
Also known to cause gremlins, is spraying anything down the throttle body, does not play well at all with the TPS.
I am also wary of changing injectors for 4 holes, unless you know how to read fuel trims, and interpret them, and are sure you have compatible injectors. I ended up putting my 170 k old ones back in when mine acted up, and everything smoothed back out. Some will say the o2 sensor circuit can correct for this, but if its out more than about 6 imo it'll cause problems.

 

Why not slap an insulator on the injector?

 

Cause 2001 is on the list:

http://www.wjjeeps.com/tsb/tsb_wj_1803103.pdf

 

or a 6 pack

 

Being an electrician, I used to use the ceramic "**** and tube" tubes from old houses, had tons of them. At one time I had them on every plug on my old s10 blazer. Work like a champ.

 

Those codes have since been cleared and not come back. I cleaned the NSS plugs but I don't think it ever was in real trouble. All the codes from the thread title are gone.

My upgrade 4-hole injectors are running fine. They have been in for almost a year now? .One day when I really understand trim readings I'll decide wether to replace them with the OG 1-hole. Research led me to believe that the 4-hole provides better atomization because the mist from the 4 hole has better spread than a single jet of fuel.

It's possible I might need a new downstream o2 but time will tell. I have until June for emissions.

 

My injectors are covered with new heat wrap that I installed when I made the injectors swap.

P0303 is common and I've always been able to fix it right before emissions
​​​​​​

 

Cool.

Literally.

BTW you got an 0331 head in that thing?

 

BTW thanks for the follow-up. Your comments about unfinished threads is noted, yeah, it's a shame.

 

I'm not quite sure which head is on it but I would put money on the 0331 because that's the most common one I've read about. Ok not really sure where I can find the label for the head and honestly I haven't even looked haha.

Somebody mentioned the temperature sensor earlier- I haven't checked that out. Could you go into a little more detail on that?

It's a shame when the solutions are left in the ether and not typed in the forums. Just trying to do my part

 

https://wranglertjforum.com/threads/...upy-head.8112/