Camry is driving me nuts

[genso]

I have posted this problem before and I thank all those who gave me advice but the original problem exists and is driving me crazy. 1995 2.2 starts fine and idles swell, until it warms and enters the loop. Then it acts like it don't want to accelerate right. At idle this is only annoying but in gear, automatic, it stumbles like it's trying to die and would if I didn't goose it and brake. it's dangerous when trying to stop and go in traffic. I've replaced coolant temp sensor and upstream o2. taken egr and iac off and cleaned as well the throttle assbly. I've followed suggestions and check resistance and voltages to the various sensor. I have retimed it and replaced coil and cap and rotor. new plugs and plug wires. run seafoam thru the fuel system and directly thru the throttle. new fuel filter. I have searched the web for similar problem with final solutions but, so far, still am stumped. I am not a novice and used to build and race stock and street chevys and fords but they had engines in them that didn't take a techy to work with. Anyone who has any helpful ideas would be greatly appreciated.

[icepickjazz]

Which sensors did you check? Bad MAP Sensor? I know you cleand some components but I recall someone suggested replacing your map sensor MAP sensor in earlier post. Saw a few posts on suggested similar problems being resolved by replacing MAP sensor. Bad TPS sensor?

[genso]

Thanks for the reply and yes I checked those as well along with every single vacuum line in system...is there a transmission sensor in this car? could that cause this problem?

[Trioxide1]

Did you bridge terminals TE1 to E1 in the Diagnostic Port to see if the idle is increased temporarily for 5 seconds ?

When you took off the throttle assembly, did you THOROUGHLY clean the idle air control valve/door? Did you verify proper operation of the little door/valve by applying battery voltage ... to see if the door fully opens and fully closes ?

When you put back the Throttle Assembly, did you put back the bottom 3 hoses (2 coolant, 1 air) in their proper location ??

Did you verify proper operation of the VSV for EGR and/or the EGR gas temperature sensor (not sure if you have this sensor sticking out of the EGR valve -- like an electric wire coming out of the side of the EGR valve) ?

Do you have a TVV (Temperature Vacuum Valve) ? It is screwed in onto the water manifold that has the ECT sensor, coolant sender unit, and then the TVV...in a row..one after another. See below:



If you have a TVV, verify operation

Verify EGR modulator? (Disk-shaped device next to EGR)

[genso]

I'll try those suggestions thanks

[icepickjazz]

When you remove the IAC check the coolant hoses running to the IAC for blockages. I think is was a problem on older 5S-FE engines, but might want to check. I have seen a couple of postings on TN and other places that these coolant hoses become blocked and cause idle problems when warm. How's the coolant level?

Read more: 93 Camry rough idle when warm - JustAnswer http://www.justanswer.com/car/09tar-...#ixzz2HTZoow4i

[icepickjazz]

Originally Posted by genso

Thanks for the reply and yes I checked those as well along with every single vacuum line in system...is there a transmission sensor in this car? could that cause this problem?

Dunno if there is a transmission sensor in the car, but using a scan tool would tell you if the car was going into limp home mode after warming up. See this video for more detail. Yes, it's a Ford, but the concepts is similar.

You Tube

You Tube

[LE PEW]

You've already checked so many things I'm wondering if you gave your EGR system a once over. If it hangs open or opens too soon it could cause what you're describing.

Just a wild @ssed guess ... good luck.

[BlackOmega]

A couple of other things you may want to check. The PCV valve and grommet (and other vacuum hoses) and lastly your fuel pressure regulator.

I recently ran into a no start/poor idle/dying 1994 Camry V6. Turned out that the PCV valve was broken in half and the rubber grommet that sits in the valve cover had hardened up causing a HUGE vacuum leak.

Check those. If the grommet is no longer pliable (rubbery), replace it; and while you're at it, replace the PCV valve too.

I couldn't believe that this caused so many headaches on my GF's car. The car would barely idle and would usually die, and it also wouldn't stay running.

Also the fuel pressure regulator, if bad, will also cause poor running issues. Easy check on the FPR, pull the vacuum hose and smell for fuel. If fuel smell is present, FPR is bad and needs to be replaced.

It also couldn't hurt to check the fuel pressure inline.

[genso]

you guys are amazing. I will recheck the items suggested and the others as well...I'm not sure about the vacuum hose you referred to on the regulator though.

[LE PEW]

Duplicate post .....

[LE PEW]

Originally Posted by genso

you guys are amazing. I will recheck the items suggested and the others as well...I'm not sure about the vacuum hose you referred to on the regulator though.

I think he means the vacuum actuated thingy on the far end of the fuel rail.



Somtimes the diaphragm tears and unmetered fuel is sucked into the motor through the vacuum line. I'm thinking that it would drive poorly hot or cold if that was an issue but it takes nothing to disconnect the vacuum line and sniff it for a gasoline smell. You might also observe actual gas dripping from the vacuum hose connection nipple on the fuel regulator with the engine running.

It's like the way that older transmissions had vacuum modulators that failed, they would suck trans fluid into the intake without showing any external signs of a leak.

Good luck.

[genso]

I rechecked iac ohms and temp coolant they are good I have taken off and cleaned egr and iac and throttle body and checked for blockages and there were none...what does that tvv do? can it go bad? I took it for a test drive and it was actually worse after all the cleaning I did. One thing to mention, I tried checking iac with a 9 volt battery and connecting center to positive and lower one didn't hardly move the valve and the upper one partially closed it. I soaked it in seafoam creep and could turn it by hand... it isn't supposed to go all around is it? It only turns about 3/8 inch or so.

[Trioxide1]

Originally Posted by genso

I rechecked iac ohms and temp coolant they are good I have taken off and cleaned egr and iac and throttle body and checked for blockages and there were none...what does that tvv do? can it go bad? I took it for a test drive and it was actually worse after all the cleaning I did. One thing to mention, I tried checking iac with a 9 volt battery and connecting center to positive and lower one didn't hardly move the valve and the upper one partially closed it. I soaked it in seafoam creep and could turn it by hand... it isn't supposed to go all around is it? It only turns about 3/8 inch or so.

Do you still have the basic scenario problem: okay when warming up...not okay when warmed up ?

About the IAC valve:

that little "door" only moves enough to be able to completely close and open the little opening. So when you turned it with your hand, were you able to completely turn the valve such that the opening was fully closed and opened by the door? Or did you feel resistance and were not able to fully close/open the door with your hand ?

As the factory service manual says:

At low temperatures the IAC valve opens and the air flows through the IAC valve and the throttle body, into the air intake chamber. During engine warming up, even if the throttle valve is completely closed, air flows to the air intake chamber, thereby increasing the idle speed (first idle operation).

When I cleaned my IAC valve, I also used a 9 Volt battery...but it barely moved the little "door" (maybe I got unlucky and had a drained 9V battery), but I hooked up two wires to the car battery. I used the car battery instead of the 9V battery. For my situation, the little IAC door did NOT close all the way. I verified that there was no blockage or debris inside the opening and around the door... So I loosened the two little screws holding the thermostatic spring housing and slightly turned the housing with the screws and re-tightened. Re-did the battery test and verified that the door fully opened and fully closed when the wires were hooked up the two different ways. Which way you have to turn it, it depends...I don't remember which way I turned the spring housing. You can see the screws on the left side of the IAC assembly (by the fingers in the photo below):



That was my scenario...on this forum most people don't mess with those two screws holding the spring housing...people just clean everything and they're good to go!

So I am just telling you this info to keep in mind...

Make sure that the rubber "frog" gasket between the IAC assembly and the throttle body is installed/seated properly and that the 3 hoses (2 coolant and 1 air) are connected in the proper location.

If you have the original ECT sensor, I would highly recommend to change it, even if it seems to be okay. An ECT that is going bad will cause all sorts of problems...so might as well be safe and replace it. It's not expensive and it's really easy to replace.

I am sure more experienced users will provide more info...

EDIT: Oh, and the TVV controls air/vacuum to the vapor canister for fuel vapor based upon if the engine is cold or hot. If this branch is not operating properly, idle/stalling issues might arise. On 1996 and newer, the 4 cyl. i don't think has the TVV anymore...instead it's a vacuum switch. I have a 1996 4 cyl with an electric vacuum switch (hence why you don't see it on my engine...in the photo I posted)

[genso]

I considered trying those little screws and adjusting but was scared after reading that you should leave them alone but my iac don't fully close. what could go wrong with that tvv?