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jonathanhead 04-28-2010 08:18 AM

Can someone help me with my Jeep....
I Have a 97 Jeep TJ. When I first start it it immediately idles high and then drops. If it is cold it will stall unless I give it some gas. If it goes to rough idle I give it some gas and it pretty much smooths right out. It remains smooth after this. I wonder if anyone could help me figure out what the problem is. I have added fuel injector cleaner. That is pretty much it so far. Your advice would be appreciated.

Bobthegod 04-28-2010 04:27 PM

Well how long has it been since you did a complete tune up? I'd start there. The a new fuel and air filter. These are all easy to do and you possibly could use them anyway. Then see how it runs. Check the timing too.

jonathanhead 06-13-2010 09:38 AM

Re Jeep Wrangler
Here is what I have done...
*Changed air filter, spark plugs, distributor
*Had a cleanup done on fuel injection
*Used Sea foam
*Changed cam shaft position sensor
any other ideas?

dkswift 06-13-2010 09:52 AM

I was just going to say "Welcome to Jeeping"
My 97 does about the same stuff. 197 on the 2.5. Now when I go to take off after a cold start (is when it's worse) or after having parked for about 20 minutes it runs like someone with a stutter trying to say "tickle king" but only at about 10-15 mph and only once. Then she runs fine. Oh, and it doesn't do it if I run out the clutch (which will have its own problems in the long run)

firefighter777 06-13-2010 10:24 AM

sounds to me like your engine is having trouble getting gas to it. i would check all of those components.

harleyharv 06-13-2010 11:23 AM

No error codes? Mine kinda did something like that when my throttle postion sensor was going out, wandering around for idle then would work fine after driving awhile.

TJ Terry 06-13-2010 12:41 PM

I would start by cleaning your Idle air control valve and throttle body with carb cleaner.

KBR97 06-13-2010 12:52 PM


Originally Posted by TJ Terry (Post 653700)
I would start by cleaning your Idle air control valve and throttle body with carb cleaner.

x2...mine did the same exact thing. Take the air intake tube off the throttle body opening. Get a old toothbrush with a little cleaner on it and scrub a little on the inside of the TB opening.

Dont buy or replace anything until you clean it.

doclouie 06-13-2010 02:31 PM

I have heard this same problem on many Jeeps that had a bad coolant sensor. They are easy and cheap to replace. If the sensor thinks it is warmer than it is then less gas is put into the cylinders. There is a way to check the sensor with an ohm meter, but do not have the specs right now. I am sure it is in the forum. If not let me know and I will look it up for you.

jonathanhead 06-16-2010 09:36 AM

Re Jeep Wrangler
I am having the coolant sensor replaced today. I will let you guys know how it goes. Thanks

nater344 06-16-2010 10:15 AM

My 97 TJ did that as well...turned out to be the TPS.

I also started by cleaning the IAC and throttle body before spending the money on the TPS. Ended up buying the TPS anyway.

Good luck...let us know.

jonathanhead 06-16-2010 03:09 PM

Re Jeep Wrangler
The error code that showed up was the cam shaft position sensor. So we replaced that. I am going to change the coolant sensor tonight. I have cleaned out the throttle body really good. I put through two bottles of seafoam and am only using high octane gas. I have my fingers crossed for the coolant sensor. Do you guys ever get squeaking in you jeep while your driving? The squeaking is like plastic moving squeaking sound?

Indy 06-16-2010 04:31 PM

Squeaking sound might be from your ujoints. Get under the jeep and check the drive shaft (both) joints. Lift one tire (front and then rear) and rotate it and then listen for the sound where it is coming from.

jonathanhead 07-03-2010 09:33 AM

So here's the latest guys. I replaced my coolant sensor and my Cam shaft sensor and I saw some improvement. Almost immediately after replacing these two sensors my catalytic converter fell apart. No correlation I am sure. After replacing the cat, the jeep is running well. My thoughts are that the cat was dying, and because the O2 sensor is in the cat, I was getting a bad message to the computer. Does this make any sense. I will keep you updated.

jonathanhead 07-12-2010 08:18 PM

Ok guys... unfortunately the cat was not the answer. I had my tps changed today and voila we are in business! That was the problem. I couple hundred bucks and a couple new sensors later we are in business!

MarkP 07-18-2010 07:14 AM

Rough Starting Fixed
I had a similar problem for about the a year. Its 1998 Jeep Wrangler and it would start fine then after 5 mins it would idle poorly. If I ran it down the road it would spit and sputter. Then, shut it off, turn it back on and it would run fine all day long until the engine got cold again. I did a lot of research on this forum so I thought I would give back by posting what I found. Maybe it will help someone in the future.
In my case, it was the upstream O2 sensor which is right off of the bottom of the exhaust manifold. I replaced it and it runs great now but what I found is that are about 6 or 7 different parts that could cause the problem. Each part is about 60 bucks. I did not get any testing codes so I just started swapping parts. I went through 3 parts before I hit the right one. Here is the list of the problematic parts. I abbreviated them but you can look them up anywhere in this forum. The parts are TPS, CPS, MAP, IAC, Coolant Sensor, Upstream O2 and Downstream O2.
First start by spraying out the throttle body with TB Cleaner. Next, do a tune-up (rotor, cap, plugs, etc). If none of that works then start swapping parts. On my Jeep, I did Downstream O2 then TPS then Upstream O2. The TPS helped a lot but the problem did not go completely away. In hindsight, I see a lot of O2 sensors getting replaced on these forums so I would start there. Also, that's what the dealership told me too. But, if you want to keep from paying $70/hr in labor then just start swapping parts. Most of them are easy to get to and unplug and swap with a couple of screws. I hope this helps someone! --- Mark

Vroooom 07-18-2010 08:10 AM

Gratz on finding the issue.

bigguns027 07-18-2010 01:19 PM

have you tried changing the coolant temp sensor? or maybe the air idle control sensor? or it could be that your jeeps computer needs to be flashed! so it can recalibrate itself! also maybe check your Egr valve to see if it maybe stuck! one way to check your codes on that is to: turn the ignition on&off three times but after the third time you turn it off then turn it back to the on position, don't start the vehicle! the check engine light should come on and stay on for about 1 min or less ! then start to flash in series! for example, if it flashes 2 times and then stops and flashes 4 more times, then that code number is 24! it will flash those two numbers like three different times to make sure you have it wrote down! just keep an eye on the light!

TerrorJ2001 07-18-2010 04:38 PM

sounds like the idle control switch needs to be replaced. I had the same problem on my old XJ.

jonathanhead 07-21-2010 08:38 AM

Hi Mark P.
I would agree with you.... switching all of these parts has led to a better running vehicle. My TJ is running pretty well, but still not perfect. I get a little hesitation when I first start it. She runs smooth like butta after that. This is definitely something I can live with although I am still wanting to get rid of the small hesitation. I think the o2 sensors are my next change. I will let you know how this goes.

jonathanhead 07-29-2010 04:48 PM

Hi Guys,
I was wrong. After a couple weeks of driving the issues are still there. I start the jeep and it revs up a then the revs come idles poorly....I give it some bogs... warm it up and it runs fine....Does anyone have any ideas?

Indy 07-29-2010 05:09 PM

Have you reset the computer yet after changing the sensors? Your computer might be tuned to old sensors so may need a reset. Leave the battery disconnected overnight to completely reset it. See if that helps.

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