It is a '99 right? Metal sensor threads directly into the manifold. Later models went to a plastic sensor in the intake tube.
About to give up
- Thread starter Gasman1979
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It is a '99 right? Metal sensor threads directly into the manifold. Later models went to a plastic sensor in the intake tube.
Like I said, the vacuum leaks aren't your issue. In fact, you'll probably see your fuel trims go further into the negative once all these little vacuum leaks are fixed.
Fix the purge valve code. I doubt it is the issue, but it isn't helping. Also, I pray to god you're chucking quality parts at this problem. Not a bunch of AutoZone crap.
Did you ever unplug the MAP and ECT sensors with the key on? That would explain those codes.
Fix the purge valve code. I doubt it is the issue, but it isn't helping. Also, I pray to god you're chucking quality parts at this problem. Not a bunch of AutoZone crap.
Did you ever unplug the MAP and ECT sensors with the key on? That would explain those codes.
Only MOPAR stuff my good man. I don’t buy shit. I never unplugged the sensors while running. I said I haven’t worked on stuff this old. I didn’t say I wasn’t a decent wrench turner. I did sort out one of my performance problems this evening. I figured out the passenger front caliper is binding like the brakes are lightly applied. It’s not enough to make it pull hard…well it is after a lot of braking, it gets progressively worse. I released it with the bleeder and gave it some space with a big flat head and the jeep whizzed down the road like everyone says theirs does. So that’s something at least. Gonna replace that caliper and line tomorrow.
Bake to the fuel issue. A new development happened tonight when the wife and I were on the way back from our rescue kennels cleaning out kennels and feeding everyone. It won’t idle. At all. Foot off gas to turn, it dies, without steady peddle it won’t run. I’ve cleaned that IAC over and over. I’m not gonna study it much. The new TB is coming with all new sensors…so I have extras now
. The STFT has corrected to what it should be. + or - 2 at all times. The LTFT is perplexing tho. It’s staying steady in the negative 20’s. The only code that has come back so far is the purge valve after I drove it a good 20 miles. So tomorrow I’m going to test the wiring to the valve and verify ground loop open when the scanner says it’s the valve should be closed and also verify that is has 12v and clean it. see if it corrects. If not I’ll buy a new one. I know that can cause the motor to suck major gas when it’s faulty. Still plugging away. Ps. Just so you know I am capable of testing all the stuff I replaced. I’m just lazy and replace with known good part was the easiest route.
It’s a 97 but sweet. I thought that was it but someone eluded to it being in the intake tube. Which I didn’t doubt because on newer cars that’s where it is. That seems a horrible place to put it
. Looks like it would be better in the intake tubing. Looks like it would leach heat from the engine and get shitty readings.It's anything BUT perplexing. You either have a rich condition, or, you have a sensor lying. The fact that it won't idle makes me lean towards it being a false rich condition. The computer is removing fuel as it thinks it needs, and ends up starving itself and dies.
The TB won't fix anything other than a tiny vacuum leak.
I’m well aware that it won’t fix anything but the small leak. I’m also well aware that it’s NOT running rich like the computer believes. I also understand that the MAP, O2, IAC and ECT all play a role in air fuel adjustments. I made the statement “perplexing” meaning…that’s the problem, I know that’s the problem, and I’m trying to sort out the why. I’m NOT a noob or a shade tree mechanic. The fact that I have replaced all but one of those sensors, the codes didn’t return, and the lean condition still exists is PERPLEXING. If you don’t agree with that statement by all means tell me what the problem is and I’ll gladly fix it. If it were a wiring issue the codes should have returned…if it were the sensor(s) the codes would have returned…..they have not. I will admit my strong suit is definitely NOT vacuum controlled shit. It’s old, outdated technology that I have little experience with. Hence why I am here…asking people who KNOW more than I do so that I can learn. I’m being as thorough with my information as I can. I cannot share freeze frame because the codes haven’t returned, so I have no freeze frame to share.
The long term remaining negative when the short term has corrected does confuse me. I understand LT is a trend and requires miles to correct…but it’s barely moving after 20+ mile trips. The trend it sees should begin to move it to the nominal zero it wants to see in a perfect world.
I’m hedging my bets right now on the EVAP purge valve being stuck in the open position. That would cause the influx of extra air introduced under the MAP so it wouldn’t be measured and accounted for in the air fuel ratio causing the lean condition.
Now you get pissy ???? You were “schooling me” rather rudely while at the same time chastising me for not finding an Intake Air Sensor in the intake tubing that DIDNT EXIST. It’s in the manifold. So thanks for the help “dude”
Man I want to see you get your jeep running, but you’ve got to bring it down a notch. There are 2 pages of people helping you, I’m not sure your strong reactions are going to get you the help you’re looking for.
I know. I felt like he was being condescending with several replies. I do indeed appreciate all the advice and help. When I try to help I want the person I’m helping to not only benefit but not feel like I’m talking down to them or being arrogant because I know more. I’m a pretty competent mechanic. Not a pro by any means. Having access to a full repair shop gives me great assets like shop key, Direct Hit, Identifix tech line and about any tool or tech you could ask for outside tuners. I played nice with him and tried my best to provide the info he was asking for to help me. When I got shitty was when he assumed I wasn’t doing things or didn’t know how to do things when I was telling him I was. Lol. It finally irritated me. I do apologize if I can off as an asshole. I try not to be. And I really am at a loss on this jeep. It’s like every time I run down a code and fix the issue another issue starts. The PO hacked up a lot of shit I’m having to repair outside this issue too.
@Gasman1979
I literally just watched a video on the temp sensor and it's location. Is your coolant temp sensor in the thermostat housing or in the block at the back of the engine by the firewall?
I literally just watched a video on the temp sensor and it's location. Is your coolant temp sensor in the thermostat housing or in the block at the back of the engine by the firewall?
Yeah, well, the other people have the advantage of not having a jeep that is in need of forum assistance, so I guess they have the luxury of acting however they like. When you're the guy in need of help, the tone of their responses will mirror yours. ¯\_(ツ)_/¯
And for context, in another thread you insisted you had the right speedo gear when it turned out you read the chart wrong, so maybe less about how much you know. You'll find that everyone here wants to help you get your jeep running, I promise.
Somebody famous once said something about how a gentle answer turns away wrath, but a harsh word stirs up anger. They went on to say that the tongue of the wise adorns knowledge, but the mouth of the fool gushes folly. So do whatever you want with that advice.
ps. Where at in Arkansas?
I admitted to FUBARing the speedo thing. And yeah. I try to be cool calm and collected. But some folks get under my skin quick. And Arkansas is your slightly more attractive neighbor to the east
The 97 TJ only has one in the thermostat housing. The intake air temp sensor was the one that had me stumped cause it was put to me this way “does the piece of crap aftermarket intake you installed still utilize the intake air sensor?” Sooooo I was looking all over for it to be in the intake air tubing. Turns out it was in the manifold. I found that one and knew what it was but was assuming there were 2 or something. It was just bad intel. It happens.
I'm not real informed on the 2.5 so I'm just throwing some data out there for consideration, but glowing exhaust manifolds can also come from a rich condition, or retarded timing. Are there other indicators you are using to determine it's running lean besides the glowing manifold?
Could you have one or more injectors leaking or stuck open? Excess fuel would explain your deeply negative LTFT. Or maybe the idiot PO put higher flow injectors in there thinking it was gonna make more power without realizing they needed a tune to correct the pulse width.
For the 2.5 experts ...Would the 2.5 PCM run without tripping a code if the distributor is a tooth off?
Could you have one or more injectors leaking or stuck open? Excess fuel would explain your deeply negative LTFT. Or maybe the idiot PO put higher flow injectors in there thinking it was gonna make more power without realizing they needed a tune to correct the pulse width.
For the 2.5 experts ...Would the 2.5 PCM run without tripping a code if the distributor is a tooth off?
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The long term adjusts to keep the short term happy and in the center of it's range so it can make quick adjustments in either direction. If short term goes all the way negative long term will adjust itself to make short term get back to near zero so short term can do it's job, short term needs to be able to quickly respond in either direction constantly , so it's long term's job to keep short term in the middle of it's range so it can do that. The fact that your long term stays negative means there is a rich condition, or a perceived rich condition. It's not going to move positive until short term starts demanding more fuel by moving positive itself, which it's not going to do if it's getting info that there is a rich condition.
This is the best video I know of on fuel trims, it's 46 minutes long but well worth it for anyone interested in understanding fuel trims.
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