jeep is running weird 1998

    Ok, so over the past year this tiny little problem with my Jeep has progressively gotten worse. About a year ago I noticed that sometimes immediately after starting the Jeep up it would sputter - it would sound like it wasn't hitting on all 6. All I'd do is put in the clutch, wait a few seconds, then drive like nothing happened. As another example, last year while down at the beach, I'd fill up at the gas station, then while leaving and turning left onto Rt 1. to go back north, it started sputtering. It barely limped through the intersection. I kept my foot on the gas and after about 10 seconds everything was normal - it got all its power back. Last winter I noticed that it wouldn't idle right over the rocks in low range, the RPMs would get low and then the engine would kick it back up to ~1k. This made it difficult to control but simply turning off the heat fixed the problem. This most recent summer the same problem came back but didn't go away even with the heat and a/c off. This season I've already driven it down to the beach and driven on the sand without issues, except that when it sputtered after starting up it started to buck with a lot more force and lasted longer than before. I've replaced the TPS, removed the throttle body, IAC, and MAP sensor and sprayed it all down with sensor cleaner and re-installed: no difference. I am unsure of where to start trouble shooting and what good a shop will do in diagnosing it. Any help is appreciated.



    Thanks a lot for reading,



    Sal

    Cps worth replacing too?

    1997 TJ 4 banger 5 speed, 4.88's, detroit tru track in the front d30, RE 3.5,OME shocks, JKS 1.25" BL, 33" BFG A/T's, Llama bumpers tire carrier, Hi lift

    Kind of a pain in the ass to check, but the sock/screen on the fuel pump could be clogged up. I think Ian had this problem once, if i remember correctly, that sucker was practically melted causing it to run like poo. Have you given it a tuneup lately? I change the plugs, wires, cap rotor and use dielectric grease on everything. I know just a tiny bit of moisture seems to reek havoc on both my xj and tj. Dielectric greese helped alot of electrical quirks. That all i got.....

    2000 Sahara, All custom...
    2000 Cherokee Police package, Beater....


    I may be slowest and the stupidest

    I had very similar symptoms a couple years ago on my '99 when the fuel pump was failing...degraded to the point of stalling out completely, having to let it sit for a minute, ran fine for a few minutes, then lather-rinse-repeat. I ended up swapping out for a new f/p and all was well. Rather inconvenient but when experiencing issues check your fuel pressure, mine would drop substantially and 'flutter'


    --Ian

    U might also want to check the ground for the fuel pump.. That can cause the pump to falter.

    Nobody belongs anywhere, nobody exists on purpose, everybody's going to die. Have a beer.


    Jeeps Owned... 89YJ, 81CJ-8, 99XJ, 93XJ, 00WJ, 05LJ, 22Bronco Badlands !

    We drove it around for a bit and it seemed to be running normal. As he was leaving (after trailing the rest of the oil that was sitting on his skid plate down my driveway and halfway out of the development =]) he said it kinda did it again but seemed normal. We let it run for a while longer and everything seemed cool. I didn't talk to him after he got home so I dunno what the final word was. It's possible he froze to death with the doors/top off and is just now dethawing. :)

    Well I was gonna give it a couple days of driving to get a better idea before I posted but here's what happened. Changed the plugs, wires, cap and rotor - and used dielectric grease (mileage wise it was ahead of schedule but time wise it's been a while). Also changed the oil - which introduced another factor - as everytime I change the oil I let it idle for a few minutes and in the past I generally start it up and drive right away. When we started it up in the garage it didn't sound like it sputtered (but a few times the idle hesitated) and after several minutes of warming up a quick drive down the street indicated no problems. As I started up to get back home I let it idle for a few minutes again, but this time I noticed the idle drop down to 200rpm then it kicked itself back up over 1k all by itself and sputtered for a while. I let it idle until it sounded normal for a few minutes and I had no issues driving home.

    Although I didn't experience any bucking the sputtering problem has only happened after starting it up and hasn't come up so my long drives down to the beach or wherever haven't been affected. I intend to drive it a few days and check the fuel pressure next time I start it up.

    Also, no check engine light. When I run my scanner, the persistent code that comes up is probably referring to the fact that my fuel gauge hasn't worked since a year after it was driven off the dealer's lot. Sometimes that things shows completely full and sometimes completely empty ... even when I fill it up :)

    One intermittent problem I had a long time ago that seemed to fix itself sounds like what Ian was describing. On a trip home the Jeep arbitrarily but slowly lost its power ... as in I'd be driving on the highway, it'd buck once or twice and the Rs would slowly die down and stall. The first time it happened I pulled over on the side of the road and it started right up again. After that, if it started to die down, I'd throw it in neutral, shut it off, downshift to 4th (as my highway speed was decreasing), start it with the key, and continue driving. I remember that the duration between each subsequent occurrence was shorter than the previous and ended up hovering around the 9-12 min mark. This was about 5 years and 40,000 miles ago and to this day has not re-surfaced (in the same form at least).

    I had bought a cheap kit to check the fuel pressure back then so I just have to find it now. The Jeep's always started and driven me everywhere ... it treats me better than I treat it.

    It's a K&N so I purposely did not replace it. I have the cleaning solution and intend to hold off until the weekend before I do anything with it. Again, thanks a lot for Glen and Geoff's help, it's always nice to have a few extra hands.

    As far as my stumbling issue goes, there are a million unresolved threads on various websites if one does a search for "idle stumble" or the like. I've been letting it warm up and the issue is nearly non-existent, I'm unsure if I'm just being too anal retentive - I figure a good mall crawling session is in order to test it out :) . Last time I was letting it warm up, while it was hovering around the 680-750 mark, I noticed a slight vibration through the pedal/Jeep, and then the engine responded by slowly raising the Rs to about 1,000. Then it slowly lowered them to the 750 mark and repeated this a few times slowly. Unsure if having intermittent issues is a blessing, maybe my Jeep's just mad at me for not being my daily anymore :)

    Thought I would bring this to the top, as my issue isn't gone.


    To recap:


    Replaced spark plugs and wires and used dielectric grease.
    Replaced TPS
    Replaced IAC
    Replaced MAP sensor
    Checked fuel pressure and it's fine while the engine sputters.


    My issue isn't as bad as it was before but I don't want it to start getting worse again and leave me stranded somewhere. Or you know, go off roading and not be able to control the RPM one day. To note, the IAC was black and looked like burnt toast when I replaced it. I have only driven it ~200 miles since and I intend to see if the new one looks anything but new in a little while.


    Thanks for your help.



    Are you running a K&N filter or the stock panel one ? Just curious

    Sal ,I just had a problem like this and it was the heater on my O2 sensor . Replaced it and the problem is gone , like you said it was always better when you let it warm up . Just a thought .

    Have you checked for bad vacuum lines?


    My '03 Ranger started throwing a code for "Lean condition both banks".


    Researched on the web and based on the info first cleaned then replaced the MAF sensor. Didn't help.


    Got progressively worse to where it wanted to stall at idle, but still ran fine on the highway.


    Was ready to replace the IAC when I found a post on a Ford forum where they mentioned they had found that one of the radiator hoses rubbed through a vacuum line.


    I lifted the hose on mine up and sure enough. It was actually a rubber elbow that joins 2 metal tubes.


    Crappy picture but you can see the huge gash right in the middle.



    Wrapped it up good with electrical tape and it fixed all the problems.



    Anyway, point is after 8-10 years in an engine compartment, rubber and plastic parts start to fail and often aren't real obvious.


    Might be worth giving a good look over.


    Quite often the hardest problems to find are the simplest ones.

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