My 99 auto starts up but it runs like it has no gas. If i don't hit the gas it will stall. If I hit the gas it just keeps it running but its extremely rough. If I spray starting fluid in it, it will run better and start easier. One in a blu moon it will idle and rev fine for a couple mins. Any ideas?
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99 xj wont stay running. runs like no gas
- Thread starter abc20abc
- Start date
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
Getting a CEL? Pulled any codes?
Just for grins, mark your relays in the PDC and then try switching them around one at a time to see what happens.
Just for grins, mark your relays in the PDC and then try switching them around one at a time to see what happens.
birchlakeXJ
NAXJA Forum User
- Location
- Melrose, MN
#1. Verify battery with a LOAD TEST. A marginal battery can give the engine management system fits, even though it might be strong enough to start the engine.
#2. What is the status of tuneup parts? Plugs, wires, cap, rotor. Always a good idea to review and replace this stuff if it has been a while when symptomatic.
#3. Verifying fuel pressure at the schrader valve on the fuel rail is never a bad idea. For your 99, you are looking for 49.2 psi plus or minus 5 psi.
Good luck and let us know what you find!
#2. What is the status of tuneup parts? Plugs, wires, cap, rotor. Always a good idea to review and replace this stuff if it has been a while when symptomatic.
#3. Verifying fuel pressure at the schrader valve on the fuel rail is never a bad idea. For your 99, you are looking for 49.2 psi plus or minus 5 psi.
Good luck and let us know what you find!
- Location
- Rainy side of Washington
X2 on all above. PULL CODES! I overfilled my gas tank (thinking the backflow sensor in the gas station's pump was just acting up again) due to these exact same symptoms and it ended up being my upstream O2 sensor.
That is not to say you should replace the upstream O2 sensor, it means you should check the codes and find out what the ECU is unhappy about, then fix it.
That is not to say you should replace the upstream O2 sensor, it means you should check the codes and find out what the ECU is unhappy about, then fix it.
its840
NAXJA Forum User
- Location
- Louisville Ky
pull you iac valve and see if its stuck..
Hickboii
NAXJA Forum User
- Location
- McChord AFB WA
i have an 86 with the 2.5l that has the exact same problem. let me know what you find out.
I did a lot of work today. I started out with a scan.
2 codes:
p0107-manifold absolute pressure barometric pressure
p1296-No 5 Volts To MAP Sensor (read on.. i changed the whole throttle body today)
-i didnt get a chance to switch the relays but i got "new" ones at the junk yard so i'll do that tomm.
1. The battery was crappy so i just bought a brand new one. Only made it start easier. No affect on how it ran
2. Today i replaced the whole throttle body with all the sensors. Idled a tad bit better (not in any way good though lol)
I then went on and replaced:
distributor cap
rotor
the sensor below the rotor
plug wires
plugs
ignition coil
It idled a little bit better than before. Still stalls down or bucks half the time though. Pressing the throttle makes it buck like hell (although sometimes it seems to rev fine but that will only last for a few mins)
3. i can try that but i have to find someone to help me
could it be that if i dont get any o2 sensor codes?
I changed the whole throttle body today(with iac, map and tps sensor)
Now since i did all this work.. what else could possible be wrong? crank position sensor? cam position sensor? manifold gasket?(the previous owner mentioned it needed one but idk if that would make it run like this?) i dont know what to do next
P.S. I greatly appreciate any input. Thanks
and hickboii i'll deff post in the thread what the problem was.
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- Location
- Rainy side of Washington
Hate to break it to you but an 86 with the 2.5L and a 99 with the 4.0L having the same symptoms will provide you very, very little info most likely. The systems have very little in common.
OP, I don't think it's your O2 sensors - it sounds like the computer is pissed about the MAP sensor, yeah you changed everything but you need to make sure the MAP sensor is getting power and putting out a proper signal. Check for wiring harness damage anywhere between the MAP and the ECU.
Ok thanks thats another thing i can check. Thanks. I also picked up an extra ecu just incase that's the problem. I found a really nice xj at the u-pull it yard today
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
You can have o2 issues without EVER getting a code. 60k to 80k and they should be replaced.
Hickboii
NAXJA Forum User
- Location
- McChord AFB WA
true i know there are a diferances but for the most part they need the same things to run fuel air and spark. but they both have computers and alot of the same sensors. and his symptoms are exactly what mine is doing so for me at least it's a place to start.
JJacobs
NAXJA Forum User
- Location
- Fort Collins CO
No, not really.
- Location
- Rainy side of Washington
I could be wrong but I think an 86 2.5 is gonna be either carbed or TBI, and it'll definitely be RENIX vs OBD-II, with a completely different diagnostic system and fuel pressure requirements... but this is just gonna distract the whole thread if it keeps going this way.
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
I'm with the others. You need to start your own thread, cover your symptoms and what you have replaced/repaired so far.
Hickboii
NAXJA Forum User
- Location
- McChord AFB WA
wow all this from let me know what you find out. well, i still want to know what he finds out. thanks for all your help tho guys. maybe your time would have been better spent keeping your mouths shut and letting me live in my own little world. i just didn't want to start yet another "my xj won't stay running" thread to add to the already 15 or 20 that i have found on the first 20 pages of threads. i'm thinking it's got to be some common part since i have seen the range from 86's to 99's with the same problem. as of yet i haven't seen any of them fixed, but i am still reading. you can keep telling me to start my own thread but i won't. thanks tho
- Location
- Rainy side of Washington
Look, we're not being meanies or something. What you're doing is almost the same as saying your motorcycle won't run well in some guy's thread about how his weedwacker is malfunctioning. Sure they both have engines and they both are failing to operate in roughly the same manner... but they are set up completely differently.
And you're confusing the crap out of the original poster's thread with your insistence on not starting your own. I'm done... responding only to the OP's info from now on to avoid confusing this further.
If yours was anything from a 97 to an 01 you'd be justified, but you're comparing things that really only share the fact that they are jeeps and have cylinders, valves, and a fuel pump. Nothing else is the same really.
And you're confusing the crap out of the original poster's thread with your insistence on not starting your own. I'm done... responding only to the OP's info from now on to avoid confusing this further.
If yours was anything from a 97 to an 01 you'd be justified, but you're comparing things that really only share the fact that they are jeeps and have cylinders, valves, and a fuel pump. Nothing else is the same really.
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JJacobs
NAXJA Forum User
- Location
- Fort Collins CO
With this logic, why don't you drop in on some Subaru forums, or GM, or.. because they're all fuel injected engines, don't they all work the same way?
To the original poster, since the computer has told you there's an issue with the MAP sensor circuitry, have you looked closer at it? Looks like you're in the middle of a parts slinging festival. Put that on hold, get out the meter and check for 5V present at the sensor, continuity to ground on the signal return and continuity to the pcm at the signal wire.
To the original poster, since the computer has told you there's an issue with the MAP sensor circuitry, have you looked closer at it? Looks like you're in the middle of a parts slinging festival. Put that on hold, get out the meter and check for 5V present at the sensor, continuity to ground on the signal return and continuity to the pcm at the signal wire.
yea i just changed all those parts because it was really cheap and the tune up stuff, well thats always a good thing to do. i didnt spend over 100 dollars on parts yet. thats including fender flares and some other stuff. I know a bit about electronics so i can test the map circuitry tomm no problem.With this logic, why don't you drop in on some Subaru forums, or GM, or.. because they're all fuel injected engines, don't they all work the same way?
To the original poster, since the computer has told you there's an issue with the MAP sensor circuitry, have you looked closer at it? Looks like you're in the middle of a parts slinging festival. Put that on hold, get out the meter and check for 5V present at the sensor, continuity to ground on the signal return and continuity to the pcm at the signal wire.
birchlakeXJ
NAXJA Forum User
- Location
- Melrose, MN
As mentioned, verify and confirm the MAP is working properly and get rid of those codes.
Still symptomatic after that, I would want to get a fuel pressure reading with a gauge....
Still symptomatic after that, I would want to get a fuel pressure reading with a gauge....
Yea the codes might be gone. I didnt scan it after i replaced the sensor, but i'll check that all out soon.
About the fuel... can i buy a gauge from a auto parts store? Is it hard to test it? What will this do.. help me figure out if the fuel pump, filter,etc is good?