97 camry, 4cy, automatic - warm start problem

[brawndo]

Hello all, I've been lurking and reading for a while, trying to solve my problem - figured I'd go ahead and ask before I drive myself crazy.

Once I have driven the car around for a while and park, this is when the starting / idling problem begins. I'll come back (30+ minutes) and crank the car, it'll start fine. It idles right around 1000 rpms. Once the engine reaches temperature (according to the guage), the rpms drop well below 500, the engine shutters and sometimes cuts off, but most of the time, the rpms then shoot up to around 2500 for about 5 seconds, then the idle will return to 1000 rpm or so when in park.

Occasionally, if I return to the car after a shorter amount of time (5 minutes or so), I have to give it some gas to get the car to start.

I have no codes whatsoever, not even a "pending" code right after this happens.

What I have done / tried so far:
I have tested the Idle Air Control Valve, the coils, and engine coolant temperature sensor with a voltmeter and all checked out both hot and cold according to the haynes manual.

I have thoroughly cleaned the throttle body and Idle Air Control Valve (off of the car).

I have replaced plugs and wires.


Thanks in advance and let me know if there are any other questions that would help out.
Brawndo

[Mister_Perkins]

Do you have a CEL on ? If so what is it?

Have you cleaned the EGR tube and Valve ?

Have you checked for vacuum leaks when the car is at operating temperature?

[fenixus]

seems like car has a problem with maintaining proper revs at warmed up idle.

how does it behave when driving and e.g. you have to stop at red light (in driving gear at full stop)?

[brawndo]

Forgot to add earlier that I have also replaced PCV valve.

To Mister_Perkins: I haven't done anything with the EGR system yet. Is there a how to on cleaning the EGR valve? I can see how to clean the filter in the EGR Modulator, and I'm also not 100% sure what you are referring to when you say EGR tube?

As far as the vacuum system, haven't gotten there, but I will go there next.

[Mister_Perkins]

the EGR and EGR tube are on the drivers side behind the intake manifold. You will need a large wrench or crescent wrench to remove it. I think its a 21mm ??( i could be incorrect ).

There are two bolts that hold the EGR in place. they are 12mm.

You will need to purchase a new EGR Gasket from the parts store. should only cost you a few dollars. Possibly need to buy it at toyota if the parts stores dont have it.

You remove the two 12mm nuts, Unplug the EGR Harness, unscrew the nut holding the tube to the head and pull it out. Then use Sea foam or some cleaner to clean it out. A lot of times the tube gets all clogged up, and the Vacuum port gets clogged up too.

Heres a thread showing the EGR clogged. You can also see the tube attached to it.
Clogged Egr Porn

TO remove it, you will have to remove the intake piping as well

heres a picture of one with the harness , you can also see the bottom of the tubing where you disconnect it from the motor:

[brawndo]

For the most part, once the car starts driving, it's ok.

Thanks for the of of EGR, would have been my guess for what to pull.

Today, car was parked for about 2 hours, wouldn't start very easily, lots of oil and gas smell coming from exhaust once it started - possibly the rings?

[JohnGD]

Maybe it's getting the fuel but not the air.

Did you clean the IAC by disassembling it and make sure the rotor turns freely? If you only spray into the vane ports it won't clean out the carbon at the bottom that cause it to stick.

Do this:
5sfe IAC Removal (lots of pictures)

Another thing to check is the engine coolant temperature sensor. It's the 2-wire sensor on the water outlet pipe (upper radiator hose outlet) on the driver side. See message #47 of this thread:
ECT switch, sensor or sender ? planning to replace

Originally Posted by brawndo

Today, car was parked for about 2 hours, wouldn't start very easily, lots of oil and gas smell coming from exhaust once it started - possibly the rings?

[brawndo]

I have cleaned the idle air control valve already.

Tonight, the car started fine but died at a stop light 2 times. I had to pop it in neutral to keep it running when stopped. Once home, I turned the car off For about 1 minute, when I re-started, it cranked right up but rpms sat at 2200, did not budge. I reved the engine a little bit thinking it would come back down but it stayed up around 2200.

Next move will be cleaning EGR valve and replacing engine coolant temperature sensor. I've read enough about the ECT now to not trust a one time resistance test.

Oh, and still no check engine light...

[fenixus]

it sounds just like sticky IAC valve.

measure resistance on IAC valve connector terminals (check below DIY), it could be out of specs.

if resistance good then get it removed together with the TB and unbolt IAC valve for thorough cleaning like in DIY:
DIY removal & cleaning of IAC

EGR valve will not react to in drive or in Neutral gears, IAC will (computer operated and affecting both idle speed and start up speeds).

[JohnGD]

How did you clean the IAC valve? Spray into the ports or disassemble?

Also, loosen the throttle position sensor and gently rotate it a little bit. It may be the idle pad area that's worn out and not making good contact.

Originally Posted by brawndo

I have cleaned the idle air control valve already.

[brawndo]

Disassembled iac, put new gasket in there as well. Will check tps when i get a chance.

Im starting to feel likethe dirty iac may be a symptom of something else. 2 weeks ago, i "cleaned" it by spraying through throttle body. Car ran fine for about a week. Then i removed throttle body and IAC and did a benh cleaning, car was ok for a few days. Could something be causing the contamination to come back that quickly? I know there's a good chance it wasnt thoroughly cleaned the first time, but the second time it was spotless, the valve was moving very freely, and it checked out during the resistance test.

[brawndo]

So....I removed the EGR valve as pictured above, and I was eagerly anticipating it being extremely clogged, but there was only a little build up. I kind of figured when I was able to remove it without PB blaster.

I'm going to pick up a new gasket tomorrow and clean, then re-install. One question, mine did not have an electrical harness. No connector or anything. I assume this is ok, but confirmation would be nice...

Also, as I removed the lower nut, I noticed "wet" oil around the coil, not just burned off sludge, but wet, like off the dipstick oil. The car has been sitting for almost 24 hours now. Could a leaky valve cover cause the coil to go bad? It tested ok according to the Haynes Manual with my multi-meter, but so has everything else, and the car still runs like crap at times.

Still no check engine light.

[fenixus]

gen4 do not have the electrical harness on EGR. ECU uses MAP readings to actuate it.

MAP rarely goes bad, but it might be also worth checking if it's good, you will need multimeter, some spare wires, paper clip, tiny alligator clips and hand vacuum pump with tight flexible tubes to do that. all can be checked at the MAP sensor connector, no need to check it on ECU end (tricky task, requires special thin mini lead probes) unless you suspect wiring harness problem.

pic not working.

check all rubber hoses of EGR and PCV, literally all thin (EGR) and thicker (one from TB to EVAP VSV by air box and 2 more being PCV breather hoses) vacuum lines around engine if all are not torn, cracked on ends or hardened, AND allowing air to pass through AND if all can hold vacuum (up to 25 on gauge) for at least 30 seconds.

checking large intake hose for cracks and tight fitment everywhere might be wise too.

it would be wise to also confirm if the timing belt alignment is good.

the oil leak you described sounds just like a leak from badly sealed/worn/cracked distributor plug, it's located right behind the coils, under the valve cover. pics in this thread:
5s-fe distributor plug leaking?

Originally Posted by brawndo

So....I removed the EGR valve as pictured above, and I was eagerly anticipating it being extremely clogged, but there was only a little build up. I kind of figured when I was able to remove it without PB blaster.

I'm going to pick up a new gasket tomorrow and clean, then re-install. One question, mine did not have an electrical harness. No connector or anything. I assume this is ok, but confirmation would be nice...

Also, as I removed the lower nut, I noticed "wet" oil around the coil, not just burned off sludge, but wet, like off the dipstick oil. The car has been sitting for almost 24 hours now. Could a leaky valve cover cause the coil to go bad? It tested ok according to the Haynes Manual with my multi-meter, but so has everything else, and the car still runs like crap at times.

Still no check engine light.

[dave255]

For what it's worth, I had a virtually identical problem to yours several years ago. Reading this thread was some serious deja vu. I spent a lot of time painstakingly removing, cleaning, testing EGR, IAC, and everything else I could think of. It really drove me crazy and took up a lot of my free time for several weeks.

It turns out it was just the ECT sensor. Removed the old, screwed in the new and the problem was gone forever.

[JohnGD]

^+1.

Also check the engine coolant temperature sensor, the two wire deal but you need a digital multimeter to check the resistance. See message #7 above.