Let's play "Name that sensor"

[XJourney]

What sensor would?
1 Miss during idle,and through full driving range
2 starts to cut out with full throttle when above 2800 rpms
3 Can't run above 2800 rpms while driving

The jeep is a '01 XJ with 41000 miles

Can't get a code from it "too new"
Have to use a code scanner.
The only parts stores we have are NAPA and Schucks
Schucks "Can't test because their program has a faultly upgrade and they can't do Imports and chryslers.
Napa doesn't do it

Any help would be appriciated

[eric91xj]

i'd bet on a faulty TPS, also though at 41,000 miles your about due for a full tune-up if ya have'nt already done it.

eric

[Scott Mac.]

My first guess would be the TPS as well. All those symptoms are throttle related.

[XJourney]

Well I tested the TPS sensor the ohms moved smoothly through all throttle positions. Is there any easy way to check the plug and wiring?
I changed my spark plugs (it is distriubuterless ignition),and cleaned my air cleaner. So not much else to do?

When I disconnect the battery and rest the computer it runs like normal for a few miles (15?)
oh one other thing the check engine lite blinks when revved (like driving)
but not at an idle(just constant on)

That was a quick response. No wonder I am a Naxja Addict
Thanks

[martin]

I'd also look at the Manifold Abs Pressure (MAP) sensor. The tube could be disconnected or partially connected.

[Scott Mac.]

How many miles are on it. Have you tried cleaning your throttle body lately? If so did you pull off the TPS and the idler motor?

[Anthropy]

OK, stupid question. Fuel filter?

[XJourney]

Don't think it is the fuel filter. Resetting the computer fixes the problem temporarily.
I have 41000 miles.
I checked the MAP sensor last night it was working fine within spec. it is a throttle body mounted one so the hose is real short less then a inch. It looked good.

Keep the ideas coming this is great:)

If worse comes worse I will bite the bullet and Take it to a mechanic.

[Bones]

Check the wiring to the CPS and to the O2 sensor(s). Sounds like something goes bad when the computer tries to go to closed loop mode.

Bones :skull1:

[MJR]

I would have the dealer make sure the cam sensor is sync'd properly (like a distributor adjustment). The dealer will have to do this on the DRBIII while in the adjustment screen as it can misread while in the view sensor screen. They have had some problems with the lock bolt not being tight enough and the shaft housing walks. Also make sure the shaft isn't starting to sieze up (another problem seen before).

[XJourney]

Well I broke down and bought a code reader(which put a HUGE dent in my driveshaft fund):(

It gave me two codes
P0203 Injector Circuit Malfunction
P0303 Cylinder 3 Misfire Detected (i asssume caused by injector malfunction

So what would cause a injector to not fire?
Wiring,PCM,Faulty Injector

So the jeep runs fine from a cold start but if i only leave it parked for a hour or so, when i restart it , it misses through the whole driving range.

Also will not rev about 2800rpm It acts like it has a rev limiter

[trailrunner]

check your wire to #3 injector,rubs on throttle bracket an grounds out,maybe a def. injector

[MJR]

Well there is a TSB for rough idle after a hot restart and misfire cylinder #3. It says this condition can be aggravated by use of high ethanol content fuel. It has you install a insulating sleeve (56028371AA) around the #3 injector for a vapor lock condition. I have done this on a friends and it helped a little. Also if you have not had the B06 Intake Manifold Debris Shield done that may help as well. There may be a updated flash available for the engine controller as well that may fix some issues. If you are out of warranty then you would have to pay for these repairs other than the recall.

[XJourney]

I have the debris shield and the pcm has a sticker that reads
"Engine Control Update 56041801AF 11/08/01"

But don't have the insulating sleeve.

So where can I read more about the TSB?

[XJourney]

You guys are ssssooooo awesome

Thumbs up all the way around

Way to go NAXJA

I guess i will head to the dealer and get the insulator Monday
And an injector O ring kit too. Can I get that for a parts store?

[MJR]

Originally posted by PNW01XJ
I have the debris shield and the pcm has a sticker that reads
"Engine Control Update 56041801AF 11/08/01"

But don't have the insulating sleeve.

So where can I read more about the TSB?

There isn't much to the TSB. You get a sleeve and cut it into 1" long pieces, wrap then around the #3 injector.

[Bryan C.]

When the check engine light flashes, it indicates a major misfire that may damage the catalyst. I would suggest you park it untill you resolve the problem.

Trailrunners post said to check the wiring to the #3 injector, good advice. When the B06 recall is done the wiring has a tendency to get caught under the bracket for the throttle cables.

Most likely it is just a bad injector. Since you bought the code reader, try swapping the #3 injectoer with one of the other 5 "good" injectors and run it to see if the code resets or travels to the other cylinder. If the code changes then replace the bad injector.

The injector sleeve sounds good in theory, but I have yet to install it and have it make a difference. Maybe those in the high heat areas of the country could tell the difference, I live in Northern California. This is just from my own personal experience.

Good luck, Bryan

[XJourney]

I checked the wires on #3 injector tested then for resistence to the PCM and the ground
Both came back as 0.1 ohms(which is the lowest resistence my Multimeter can do)

And it only acts up on hot starts, I took if for a 20 mile test this morning and no code came up. Then I shut it off for 30 minutes and restarted it and right away I had a code.

I understand how that injector gets so hot, I burned myself last night on the throttle bracket.
Also I just recently switch my gas to Safeway from Chevron. For price reasons. (Ethanol?)

Is there any problem with switching the injectors around when in put the sleeve on?

Thanks alot

[Bryan C.]

Well, I decided to look at the TSB again to make sure I wasn't talking out of my @ss as usual. The TSB makes no mention of a P0203 injector fault code, only a P0303 misfire code. You can try the sleeve and see what happens, might just be a good idea to have it on there anyway. Try the injector swap and see what happens. You could do both at the same time.

Bryan

[MJR]

I suppose someone could cut the injector wires by doing the B06 Recall but if it was chances are the JTEC will be damaged as they do not take kindly to shorts to power or ground depending on the wire. Of course if it was unplugged with the key on it would trip the code and store it.

Swapping injectors is relatively easy but I doubt that would be the problem.

[XJourney]

Well so I switched the number 3 injector with the number 1 injector. And the problem followed

Now I get
P0201 Injector malfunction cylinder 1
P0301 Miss fire cylinder 1

Sound like the injector to me

So some of the symptoms of a bad injector can be
1 miss through driving range on hot starts only
2 not being able to rev above 2800 rpms

So tomorrow I will replace my injector(s)
So can I replace 1 or should I replace all of them?
What brand is a good one? (price is a concideration)

Thank you

[MACH90XJ]

Good job,that's some damn good trouble shooting you guys did.Fiveomotorsports.com has injectors at the best price I have seen so far,and as far as quality I havent had a problem with the mustang injectors I put on my '90.You can e-mail or call the guy there and he will answer any questions you might have,very helpful people.

[MJR]

Before I would pay for a replacement injector I would see if the emissions warranty (if still in, depends on selling state) is good and covers it. Since it's a problem like you have and no leaks then you can replace just the one.

[XJourney]

I am not sure if I am going to mess with warrenty. They will have to do their own tests/diagnoistics(time that I don't want to waste). And I am going camping this weekend:D
The rest of my injectors looked great(well i guess the faulty one looked great too:confused: )
I will be a cheap bastard and replace just one injector for now and then look into ford injectors, 23pounders right. And maybe buy the insulator too.

Thanks to everyone that helped.
You all can come over for beer and cookies if your in the neighborhood.

[MACH90XJ]

I dont think you want 23lb,its more like 19 lb.Its not the poundage upgrade in mustang injectors its the spray pattern.Something like 30 degrees versus 60 degree,1 hole versus 4 hole.

Ordered injectors on internet,2 days later there on my doorstep with o-rings already on.Not sure if they sell singles.

[MJR]

Originally posted by MACH90XJ
I dont think you want 23lb,its more like 19 lb.Its not the poundage upgrade in mustang injectors its the spray pattern.Something like 30 degrees versus 60 degree,1 hole versus 4 hole.

Ordered injectors on internet,2 days later there on my doorstep with o-rings already on.Not sure if they sell singles.

19.7lb are for the Renix 4.0L's. The poundage has changed three times on the 4.0L mostly due to fuel pressure increases. The newer style injectors have different connectors.