rough idle & jerking on freeway?

[theredmonster]

This is my first post here on the forums. I am not a mechanic but i am pretty good with my hands. I went to auto mechanic school when i graduated hs in 02 but never started to work in the field. Just basic repair and maintenance on my car as well as friends and family for extra cash.

so i purchased my 1993 toyota camry used with 187,000miles about 3 years ago. It now has 290,000 miles on it. When i first purchased the car it wouldnt start on cold winter days. It would turn over start and die. I would have to keep my foot on the gas until it warmed up and it would be fine. I dismissed it since the car is so old and had so many miles. As time went on during these colder days it started to idle roughly, Jumping from 400-750RPMs. I still did nothing since the car worked and it didnt do this all the time, just on cold mornings and cold starts. The car started fine and idled fine once it warmed up.

About 2 years and 60,000 miles later the rough idling started to happen during the warmer days and warm starts. Now the car does this all the time, even after it has warmed up. It idles rough first thing in the morning, at red lights, and basically whenever the car is at a stand still. if i step on the gas and bring the RPMs a little shy of 1k the car idles fine. During cold starts if i dont keep my foot on the gas the car will die. once it has warmed up it will not die but idles rough.

Another symptom but im not sure which other symptom this may be related to. The car is slugish to accelerate from a dead stop. When i am at a dead stop and push the gas it puts along until it gets to speed, it accelerates fine once its about 35mph, but theredmonster takes its time getting to that speed. it feels like it doesnt matter if i slowly accelerate or go wot it get to 30 mph whenever it feels like it.

Different symptom but i believe it is unrelated to the rough idle. But i could be wrong im not a mechanic. The car jerks when i am coasting on the freeway. When im driving on the freeway and i start to coast,(when my foot barely pushes on the accelerator to maintain speed usually between 60-70mph) the car will begin to jerk ROUGHLY. It feels somewhat similar to the jerking from a worn out spark plug or plugs. The check engine light came on and the codes i pulled were exhaust is rich and engine knock sensor.

When reading on forums most of the threads point towards the EGR valve for what i believe to be similar symptoms. Before i shell out 150+ i want to make sure i exhaust all other options first.
Yet i've also read that rough idling can be caused by a faulty tps, IAC valve, pcv,or distributor cap and rotor.

Any suggestions on what to test, or what to clean? And if there are multiple things to test and clean, what order should i trouble shoot these issues? I figured i would post a thread first before i start spending my weekends taking out, testing, cleaning, and replacing parts. I recently did a tune up on the car at 270,000 but i did not replace the distributor cap or wires. any suggestions would be great.

[zythr]

Originally Posted by theredmonster

This is my first post here on the forums. I am not a mechanic but i am pretty good with my hands. I went to auto mechanic school when i graduated hs in 02 but never started to work in the field. Just basic repair and maintenance on my car as well as friends and family for extra cash.

so i purchased my 1993 toyota camry used with 187,000miles about 3 years ago. It now has 290,000 miles on it. When i first purchased the car it wouldnt start on cold winter days. It would turn over start and die. I would have to keep my foot on the gas until it warmed up and it would be fine. I dismissed it since the car is so old and had so many miles. As time went on during these colder days it started to idle roughly, Jumping from 400-750RPMs. I still did nothing since the car worked and it didnt do this all the time, just on cold mornings and cold starts. The car started fine and idled fine once it warmed up.

About 2 years and 60,000 miles later the rough idling started to happen during the warmer days and warm starts. Now the car does this all the time, even after it has warmed up. It idles rough first thing in the morning, at red lights, and basically whenever the car is at a stand still. if i step on the gas and bring the RPMs a little shy of 1k the car idles fine. During cold starts if i dont keep my foot on the gas the car will die. once it has warmed up it will not die but idles rough.

Another symptom but im not sure which other symptom this may be related to. The car is slugish to accelerate from a dead stop. When i am at a dead stop and push the gas it puts along until it gets to speed, it accelerates fine once its about 35mph, but theredmonster takes its time getting to that speed. it feels like it doesnt matter if i slowly accelerate or go wot it get to 30 mph whenever it feels like it.

Different symptom but i believe it is unrelated to the rough idle. But i could be wrong im not a mechanic. The car jerks when i am coasting on the freeway. When im driving on the freeway and i start to coast,(when my foot barely pushes on the accelerator to maintain speed usually between 60-70mph) the car will begin to jerk ROUGHLY. It feels somewhat similar to the jerking from a worn out spark plug or plugs. The check engine light came on and the codes i pulled were exhaust is rich and engine knock sensor.

When reading on forums most of the threads point towards the EGR valve for what i believe to be similar symptoms. Before i shell out 150+ i want to make sure i exhaust all other options first.
Yet i've also read that rough idling can be caused by a faulty tps, IAC valve, pcv,or distributor cap and rotor.

Any suggestions on what to test, or what to clean? And if there are multiple things to test and clean, what order should i trouble shoot these issues? I figured i would post a thread first before i start spending my weekends taking out, testing, cleaning, and replacing parts. I recently did a tune up on the car at 270,000 but i did not replace the distributor cap or wires. any suggestions would be great.

Here's a serious, suggestions, retire, theredmonster. It is probably "tired" of highway and city street driving, and just wants to be left alone. If that is not the case, have you checked the fuel injector(s), have they ever been cleaned if you know?

[Stillrunning]

Originally Posted by theredmonster

But i could be wrong im not a mechanic.

You think we are one?

Any suggestions on what to test,... I figured i would post a thread first before i start spending my weekends taking out, testing, cleaning, and replacing parts.

Any suggestions we make will be to the, "testing, cleaning, and replacing parts". No magic solutions.

Have you ever done a compression and vacuum test? The car is 19 years old with almost 300k miles, they do eventually just die you know.

[theredmonster]

@zythr i have not cleaned the injectors nor do i know if they have been cleaned before i got the car. i will definitely look into that. If i ran fuel injector cleaner for the next couple full tanks, will that help/fix clogged injectors?

@still running i know not everyone on this forum is a mechanic but i was hoping that some seasoned gear heads would have a better insight than i have. I also know that all replies would be to test, clean, or replace. I was hoping to find an answer on what to test and in what order. I also have never done a compression or vacuum test on this car because i do not have the tools to do so. But maybe this will give me an excuse to go blow some cash on new tools

thanks for the quick replies. I will be testing the voltage on the tps to make sure it is in spec, as well as test the iac valve. If the IAC passes i will continue to clean it out. Plan on replacing the fuel filter (less than 20 and probably needs it), PCV (less than 5) and distributor cap and rotor (less than 25) this weekend. Ill reply this weekend to let you guys know how it goes. If the car is still idling rough, ill probably end up shelling out the 150 to get a new one. happy wrenching guys.

[BMR]

V6 or 4 cylinder motor?

I recently did a tune up on the car at 270,000 but i did not replace the distributor cap or wires.

What, exactly, was done in this "tune up"... plugs, air filter, PCV valve??

So you bought it at 187k?... it's most likely due for new cap, rotor, plugs, and wires; 100k miles is the recommended interval. Even if that doesn't fix it, it certainly wouldn't hurt.

Also, cleaning the IAC would be another good thing to do. Doesn't cost anything, and it's a common source of the problems your car has. Especially the erratic idle RPM problem.

[theredmonster]

@BMR it is a 4 cylinder. i had changed the belts, air filter, oil change, plugs, coolant swap, transmission fliud flush, brake fluid flush, powers steering flush. I had also replaced the air intake housing because it was cracked. Thanks for the advise as well. I will let everyone know how the fixes go and what symptoms are gone

[Slaz's92Camry]

Wow this sounds pretty similar to what my car does at idle and when coasting on the hwy please post if u find a solution! hopefully all goes well

[zythr]

Originally Posted by theredmonster

@zythr i have not cleaned the injectors nor do i know if they have been cleaned before i got the car. i will definitely look into that. If i ran fuel injector cleaner for the next couple full tanks, will that help/fix clogged injectors?

@still running i know not everyone on this forum is a mechanic but i was hoping that some seasoned gear heads would have a better insight than i have. I also know that all replies would be to test, clean, or replace. I was hoping to find an answer on what to test and in what order. I also have never done a compression or vacuum test on this car because i do not have the tools to do so. But maybe this will give me an excuse to go blow some cash on new tools

thanks for the quick replies. I will be testing the voltage on the tps to make sure it is in spec, as well as test the iac valve. If the IAC passes i will continue to clean it out. Plan on replacing the fuel filter (less than 20 and probably needs it), PCV (less than 5) and distributor cap and rotor (less than 25) this weekend. Ill reply this weekend to let you guys know how it goes. If the car is still idling rough, ill probably end up shelling out the 150 to get a new one. happy wrenching guys.

Hmm, I'm not sure if the injector cleaner would work. but maybe someone else who may have tried it, could provide some insight.

[liensalebuyer]

I have a 00 Tacoma, same tank of gas for maybe two years. Let a co worker borrow it and he fills the tank up. Running really rough. My other co worker mechanic was telling me valve might have been bent because the design for the 4 cyl taco was poor. I asked him about fuel injector cleaner and he was telling me it might not help, how about selling the truck to him with 60K miles, 2000. Yeah, sure. There was some bottles of cleaner at work (fleet of cars and trucks) and bingo. Ran the truck for about an hour, driving it more than I had in two years. Emptied the tank, put mid grade gas for half a tank. No problems since. Used Ford injector cleaner, I think any will do including Chevron.

[BMR]

Originally Posted by theredmonster

@BMR it is a 4 cylinder. i had changed the belts, air filter, oil change, plugs, coolant swap, transmission fliud flush, brake fluid flush, powers steering flush. I had also replaced the air intake housing because it was cracked. Thanks for the advise as well. I will let everyone know how the fixes go and what symptoms are gone

Ah, OK, the 4 cyl. Here are a couple of DIY threads for cleaning the IAC on the 4-banger. It's best to take it apart as far as is practical to clean it. Sometimes folks spray some throttle body cleaner down it, and it works. Sometimes not.

IAC cleaning thread 1.

IAC cleaning thread 2.

[theredmonster]

THANK YOU BMR! Funny enough i already had both those threads bookmarked and i have been reading them over to "study" a little before i get my hands dirty. I appreciate the links and help. I'm definitely going to keep the first thread open while i work on the car.

[theredmonster]

Well TheRedMonster survived surgery today!!

First off thank you everyone for the suggestion and tips.

I started with cleaning the IAC. To do so I had to remove the intake ducting (or whatever its called). I also had to remove the throttle body because I couldnt reach the clamps on the coolant lines on the IAC. I scrubbed and sprayed with intake cleaner the throttle body, intake manifold, and IAC. That stuff was straight CAKED on. I also wanted to change the fuel filter and that was pretty easy since all the intake stuff was out of the way. I also changed the plugs, distributor cap, and rotor. Easy except the rotor i had didnt fit. All the forums and pictures online showed the rotor with the arm. Once i took off the cap i noticed my rotor looked like a dish that was held on by 2 screw. I had to ride my bike down to the car parts store. What a momentum killer. Put it all back together which is way easier than taking it apart. Started the car and it was STILL IDLING ROUGH!!!ARGGHHHHHH!!!! The car also started kicking out some smoke but i figured as much especially when i sprayed the intake manifold with intake cleaner and scrubbed it down with a toothbrush.

When i was taking the throttle body off. I noticed that the hose located to the left of the 3 hoses, that come out on top of the throttle body came off way too easy. I especially noticed this when all the other hoses were such a pain to take off. Some hoses were so hard and brittle that when i tried to pry some off with a flat head they crumbled. what do you expect thredmonster almost has 300k and is still on its original motor. So i took the hose off and BOOM....... it idled fine. a little high but not rough. YES!!!!!!! i put the hose back on and rough idle. Took it off and plugged the nipple with my finger and fine again. All that and all it was, was a vacuum leak. I needed to clean the IAC anyways, it was REALLY clogged. I took the car on the freeway and..... I CAN COAST AT 65!!!!! WITH NO JERKING!!!!! i contribute this fix to the new plugs, cap, and rotor.

Now i need to unplug the battery to reset the ECU cause the car is still has a CEL. I checked it before and it said that the exhaust was rich and also the knock sensor. I attributed that to the rough idling and jerking on the freeway. Hopefully these fixes fix the CEL too.

thanks again