97 Chev Cavalir Runs Ruff

Home  \  Repairs & Maintenance  \  97 Chev Cavalir Runs Ruff

{hugs}

posted by  sskula

so come on guys give me a hug 8)

posted by  Unfedfat

Saying I like to waste my money what do you think. How many people do you think like to waste there money? When did I say I did? I didn't. If I like to waste my money I would take it to a dearlership and waste it there. That is why I have been searching for someone to help. Maybe you shouldn't put words in people mouths. Look at what you wrote. Talk about no being nice.

posted by  sskula

Well if that's your attitude then how's this for a reply. Go piss up a rope jackass.

posted by  vwhobo

No codes, we have done checking with no good, and we replaced both O2 sensors because that was the only thing on the computer that was bad, so no jerk, I don't like wasting my money, that is why I am asking here.

posted by  sskula

Have you checked for codes and looked at the data stream? It sounds like the answer is no. Always start at the begining, it makes things so much easier. Unless you enjoy wasting money which it looks like you do.

posted by  vwhobo

Ok guys, I have a problem with my 1997 Chev Cavalir, when I first start the car it runs ok(in a open loop), then it starts to run ruff(as soon as the car goes into a closed loop). I have replaced the spark plugs, both O2 sensors, EGR valve with no luck. If I disconnect either O2 sensor the car will stay in an open loop and everything runs good. My guess it is a sensor. But what sensor would be the problem? Or any help would be great.

posted by  sskula

Okay Ace, let's start at the begining.

1. Your first post you stated that you replaced seven items (1 EGR valve, 2 oxygen sensors, 4 sparkplugs). The number of four sparkplugs is another assumption because you gave incomplete information. You also never stated that you downloaded any codes. I guess you want people to help you without giving them all of the information.

2. Your second post you act like a jackass by calling me a name. You also state "and we replaced both O2 sensors because that was the only thing on the computer that was bad". No codes tell you ANY component is bad unless you are performing beta testing for OBD III systems. All OBD II does is point you to a system then you have to be smart enough to isolate the defect. Apparently you do not meet that criteria.

3. When someone doesn't have the experience or knowledge to deal with a problem of this nature it's more often than not cheaper to go to a qualified tech. Looking at your shopping list of parts you've already spent in the neighborhood of $350 and haven't fixed shit. I can almost assure you at any one my shops you would have been diagnosed, repaired and out the door for about 50-75% of that cost. So yeah, it looks like you like to waste money to me.

4. I haven't put words in anybodies mouth. I had to make a judgement call based on more of your weak information. Ya see, today my crystal ball is in the shop so I can't use it. And I never talk about being nice.

Moral of the story. Those who help themselves are much more likely to get help from others. One more thing. Read my signature block, which are you?

P.S. If Adam wants a hug he should try snoope or ock. They seem to be traveling that direction based on some of their latest posts. :D

posted by  vwhobo

HAHAHA
that's what i was thinking :mrgreen:

posted by  Unfedfat

There's nothing wrong with good manly hug P All you have to do is ask lol

posted by  snoopewite

Oh baby, can we please? :twisted:

posted by  vwhobo

don't act like a dick to people and maybe they would give you all the info you need. But when you make rude comments like you did first, people are going to treat you the same way you treat them.
I don't do this forums things everyday so if you needed more info all you had to do is ask.

posted by  sskula

Okay moron except there's one fly in your ointment. You're the one who started the thread. You are the one who gave insufficient information in that first thread.

As for what you consider to be a rude comment, that was an observation based on your post. Notice that through all this you still haven't explained the things I've asked or refuted what I've said about diagnosis. Or the price of the parts you've wasted your money on.

One more thing. I don't have to be a dick until somebody is an idiot. Today that person is you.

posted by  vwhobo

All you had to do is ask, not assume what I did. Very easy to say could you explain more. You assumed and started this is an assumtion. If you would have asked for more info about my first post you would know more.
And I haven't explained like you said because you continue to want to fight and be rude.
A simple post asking for more info is what a normal person would do.

posted by  sskula

Here, try this. Look at the very first sentence in my very first post in this thread. It has a question mark at the end so I thought it was a clarifying question. You told me "No codes, we have done checking with no good, and we replaced both O2 sensors because that was the only thing on the computer that was bad, so no jerk, I don't like wasting my money, that is why I am asking here."

So not only did you contradict yourself (it said the sensors were bad but there were no codes?) but the scan tool doesn't shoot down the sensors anyway as previously covered.

As for fighting and being rude, you were the first person to call names so... That doesn't seem like a very good way to befriend the only person here that is likely to help you.

Where does that leave us? You still haven't supplied complete information. You still have spent a pile of money on parts that didn't fix your car. You still haven't addressed statements I have made telling you why you're jumping to conclusions on your car. And last but not least you are the one who needs help, not me. If you want it I'm always happy to give it as many people will attest, but first you have to do your part which you haven't. The ball is in your court. Have a wonderful day.

posted by  vwhobo

Gee, I guess that means you really have no interest in helping yourself. Your loss. :rolleyes:

posted by  vwhobo

I was busy, sorry for not watching this forum everyday.

posted by  sskula

ok here we go, I will try my best.
About a year ago I noticed that when I start my car, about 15 seconds after it my cars RPMs would drop to about 300 then back to 900 and back and forth for about 10 seconds or so. My friend thought the quckest way to fix it was to try new spark plugs. That didn't help.(FYI we didn't have a snap-on computer yet).
We then did some research and there was a TSB that said "77-61-09B OCT 97 Engine - Rough Idle/Miss/Cold Stall/High Oil Pressure ", the car was pushing 100 psi on the oil pressure all the time. We replaced the oil pump and my oil psi dropped to 30 to 60 psi. But that didn't fix the problem.
My car then threw a code that said where was a problem with the EGR valve. EGR was $139 so I swapped the egr with my wifes car that is working perfect and my problem didn't fix itself and her care still runs good. We now have a snap-on (i think the model # is MTG250029999), it did show a problem with the front and rear o2 sensor. We replaced them and the computer showed them working good but I still have the problem.
I hope this explains everything. Anything I left out just let me know. Thanks

posted by  sskula

Okay, let's go.

1. I know I'm working with a Quad-4 now, but only because I chased it down by the TSB number.
2. What code did it throw before you replaced the EGR? Does it still throw the same code?
3. What was the code that made you change the O2 sensors? If no code what exactly was the problem the scan tool was showing you?
4. Your first post says it runs good cold or with the O2 sensor disconnected and rough warm with the O2 connected . Your last post says 15 seconds after startup it goes to hell for 10 seconds. This is a direct contradiction, which is it? One O2 diconnected, if so which one, or both? Cold or hot start? Both?
5. How many miles are on the engine? Any modifications?
6. If you have access to a Snap-On scan tool and TSB's you must work in a shop. What does the drivability tech think it is?

That should give us a good start.

posted by  vwhobo

[1. I know I'm working with a Quad-4 now, but only because I chased it down by the TSB number. ]
[2. What code did it throw before you replaced the EGR? Does it still throw the same code? ]
It said EGR was out of range. I am working with a freind that has this snap-on machine. We cleared the code and it threw it again so I swapped it with my wifes car. It didn't make my car run any better and no codes on mine or her car since.

[3. What was the code that made you change the O2 sensors? If no code what exactly was the problem the scan tool was showing you? ]
We look at the number rnage on the O2 Sensors. it falls(i am doing this from my head becasue I am not over to his house to look at the book) between 80 to 800, wen you give it gas it should go to around 800 then fall back down to the 100 range and both o2 senors would go to 800 and hang there for a few minutes and come back down very very slowly and the snap -on book said the o2 should fall back alot quicker so we replaced then and from what the snap-on computer and book shows it looks good.


[4. Your first post says it runs good cold or with the O2 sensor
disconnected and rough warm with the O2 connected . Your last post says 15 seconds after startup it goes to hell for 10 seconds. This is a direct contradiction, which is it? One O2 diconnected, if so which one, or both? Cold or hot start? Both? ]
If both o2 are connected, I start the car which it is in a open loop for about 5 to 15 seconds, it then goes into a closed cloop and that is when the rpms go from 300 to 900, then back to 300 and then to 900 for about 10 to 15 seconds.
If I disconnect the rear o2 it stays in an open loop and the car runs fine with no problems.

[5. How many miles are on the engine? Any modifications? ] 96,000 and no modifications
6. If you have access to a Snap-On scan tool and TSB's you must work in a shop. What does the drivability tech think it is?
No, he just does side work, he bought this scanner because a freind had one and I am looking the TSB's up on the internet.

Thanks for you help.

posted by  sskula

1. On initial testing of the O2 sensors you said they would drive to 800mv and hang before coming down. Did they go up and down more or less simutaneously?

2. After O2 sensor replacement are they reading the same as one another or are they reading differently? Either way what are the ranges for each.

3. I'm still not clear on the idle hunt. Are you saying it does it for 10 to 15 seconds and stops or it does it every 10 to 15 seconds or what?

4. Still want to know what the EGR code was.

5. Just want to make sure on this one. Disconnecting the rear O2 makes it run okay. What happens if you disconnect the front? If you haven't tried it please do.

posted by  vwhobo

[quote="vwhobo"]1. On initial testing of the O2 sensors you said they would drive to 800mv and hang before coming down. Did they go up and down more or less simutaneously?
On the old one they would go up and not come back down for the most part. On the new ones they come back down alot quicker.

2. After O2 sensor replacement are they reading the same as one another or are they reading differently? Either way what are the ranges for each.
I will get with my friend and get those numbers for you.

3. I'm still not clear on the idle hunt. Are you saying it does it for 10 to 15 seconds and stops or it does it every 10 to 15 seconds or what?
I will start it and it runs good for about 10 seconds(at this point it goes to a closed loop), then the rpms go from 900 down to 300 and back and forth maybe 3 to 5 times, then it will stay at 900 rpms,after that it will not keep dropping to 300 rpms but will run a little ruff, if I floor the car from a dead stop, it go like there is no problem, just if I leave it idle it runs a little ruf, and I Think I hear some small sputtering out the tail pipe at idle or if I floor the car while not driving i will hear a sputter out the tail pipe when the rpms come back down from 4000 rpms back to 900. just a little, maybe once or twice every minute.

4. Still want to know what the EGR code was.
I will also get with him on this.

5. Just want to make sure on this one. Disconnecting the rear O2 makes it run okay. What happens if you disconnect the front? If you haven't tried it please do.
Shoot, we did it and I forgot if it stayed in an open loop. I know the rear(near the cat) when disconnected it stayed in an open loop and ran good, but not sure on the front(non-heated o2). I will verify this as well.

Thanks for your help.

posted by  sskula

Alrighty then, I'll be looking for it.

posted by  vwhobo

How about the answer to #3, does it help at all?

posted by  sskula

I don't know, I need all the pieces of the puzzle. Remember I can't see the car so that makes it a little (maybe a lot) tougher.

posted by  vwhobo

This sounds electrical in nature for sure...

one little resistor went to the market
one little resistor stayed home
one little resistor burned up and went kaput ,causing the circuit it was part of ,make a 1997 Chevy Cavelier run rough.

posted by  Nemaroller

Okay, I'll be looking for it. And no, he doesn't have any idea.

posted by  vwhobo

Any ideas where?
And vwhobo, my friend will be back on Monday and he is comming over sometime then to explain a little more to you.

posted by  sskula

Not to sound like i know whats going on but could the catalytic converter be stoped up ??

posted by  muddy4x4man

Forgot to have my friend write you back vwhobo. He is comming over tommorow so I will have him post.
No, the converter is good. Two people looked at it.

posted by  sskula

ok, vwhobo, I am the mechanic that has been working on sskula's car, the owner of the mt2500 scanner, and his mechanic.
The obd II code that was set for the egr valve stated that the egr value was out of range, i can not recall the exact number of the code. I will try and look that up. After we had installed his wifes egr valve on his car, found out that didnt fix the problem, we reinstalled his( after visual inspection for pluged or carboned up passages) and since then(about 2 months ago) the car has not set one single code for the egr valve. The O2 sensors at first were sluggish to respond. the rear would stay at around 20 to 100mv for about 5min of the car running, then barley go above 200 during reving of the engine. We replaced that O2(heated) and reading would hoover around 450mv, and bounce between 900 and 100 upon acceleration and deceleration. the front o2 sensor also is functioning ok after we replaced it. The rough idle occurs in a open loop only (engine warm or cold). I assume you know this, but for clarification, if you unplug the rear o2 sensor, it will fool the car and keep it in open loop. the car will run good forever, no matter what the conditions. with the rear o2 sensor pluged in, after the rear o2 sensor reaches operation temperature, it will put the car into closed loop. as soon as it goes into closed loop, i mean like you flipped on a switch, it will idle search and run slightly rough. The rough running is very slight, and causes a slight vibration or roughness. But the idle searching is very noticable. The idle search is amplified if you do a throttle snap (bring it up to about 3000 and let it go back to idle, it will hoover at about 800, the drop drastically to 300-400, the the engine will automatically kick back up to 1100 or so, the keep searching). I have monitored all sensors with the Snap-on mt2500, and nothing is out of the ordinary. It is also not throwing any codes. I have listed to the engine with a "chassis ear" to hear the internal engine, and the valve train, timing chain, lower end, and everything sound great. the car has about 98,000 miles on it. There have been no modifications to the engine at all. I am having a hard time figuring out what sensors/paramaters the closed loop incorprates and starts adjusting for when it switches from open to closed loop. If you need any measurments from any sensors, please let me know, and i'll hook up the scanner and let you know. Just a couple of weekends ago, we installed a new fuel filter because it was the original filter, with no improvement to our problem. Thank you for any help!
--James

posted by  sskula

Okay, let me give it some thought and do a little research. My first reaction is to say give the IAC, IAC passage, and throttle body a spray can clean job and see what you get. It'll only cost $2 and take 30 minutes. And you know I've only got a 50/50 chance of being right. At least it'll take that out of the picture.

posted by  vwhobo

Your Message