Cold Start Issues - Toyota Nation Forum : Toyota Car and Truck Forums

[SMAN] · 12-19-2005, 02:44 AM

Ok so I'm having an issue where if I leave my car long enough so that the engine cools down, when i go to start it back up, it kicks in and turns over, but the idle and stuff doesn't stay high enough to keep the engine running so it stalls after like 1 second. I did a bit of searching and was thinking it might be the coolant temperature sensor, except that my temp guage on my dash is working fine. Another thought would be that it was the themostat. My dad says that we had this problem fixed a few years ago (I guess it's back again) and that they replaced the cold start injector, but after doing a bit of research i've learned that my I4 doesn't have one of those. So any idea what they might have replaced and how easy it would be to replace again?

JerryR · 12-19-2005, 08:20 AM

Try cleaning the Idle Air Control valve.
To access it, remove the air intake hose from the throttle body , on the lower surface of the TB you will see a square opening, Spray an Oxygen sensor safe solvent into it, (you may have to do it a few times) hopfully it will disolve the crud that is in there, to permit the valve to move freely.
HTH
JerryR

[SMAN] · 12-19-2005, 10:56 AM

I don't think that's it. The car works fine when the engine is warm, and occasionaly (1/50 starts) the high idle will catch and keep the engine running. Otherwise i have to give it some gas to keep it running.

[SMAN] · 12-19-2005, 04:26 PM

Ok so i went down to the toyota dealership today and got the repair history for the car. Aparently, what was replaced last time was the Idle Air Control Valve because it was scored and was sticking. I guess this is haveing the same problem again. I'm going to try and take it out tonight and see if i can clean it or something. If not a new one of these is $250. Aparently it's not the temperature sensor because when those die, the check engine light comes on.

noodlerooney · 12-20-2005, 02:46 PM

94 Cam LE I4: Many people have replaced the IAC only to have the problem reappear a year later. Most say clean it, I have also heard that some also lubricate it after cleaning. Seems that there is metal to metal contact in the valve that benefits from lubrication. Having the same problem myself. Have tested the valve many ways as per the factory repair manual and everything checks out ok. Only have this problem if the car is sitting for more than 10 hours, less than that it cold idles ok. Will have to try the lubrication of the valve, if only it wasn't so damn cold out.

[SMAN] · 12-20-2005, 04:32 PM

what kind of lubricant did they use?

bigrichbx · 12-20-2005, 07:57 PM

clean the throttle body also! if its really dirty then it might not be getting enough air in when u turn it on. worth a try.

[SMAN] · 12-20-2005, 09:17 PM

I plan on cleaning both the throttlebody and the ISC tomorrow. I'll let the car cool down all night then start on it in the morning. I picked up a new gasket from the dealership for a few bucks today and some STP throttlebody cleaner from autozone. I'll use a toothbrush or something to clean the whole thing and i feel pretty confident on taking it apart.

noodlerooney · 12-21-2005, 07:57 PM

94 Camry LE I4: They used a lubricant used for motorcycle drive chains, forget the brand name. I'm going to try a little silicon spray and then cycle the valve open and close by pulling the plug and putting +12 volts to the center male terminal and then alternately ground the bottom(open) male contact and then ground the top(close) male contact. I have made wire leads that I can use that are insulated(used a butt connector flattened out a little for the female part of connection) at the contact points so I don't short out anything. I have cycled the valve before and it performs ok. I figure it has to be binding somehow when sitting for a long period of time. This valve is a real pain in the a** for a lot of people. If this fails to work, I might have to test the output from the ECU itself. This test is the only one the factory manual doesn't say to do. It says to test all the way to the ECU, but not the actual signal output from the ECU. It say if all tests are ok, replace the ECU. I think I'll test the output of the ECU first, thank you much. I noticed that the valve goes to mid position(800 rpm) when the plug is unpluged from the valve. I would have guessed that it would have stayed at its last position before being unplugged. I have also checked all the other sensors involved with the performance of the IAC, specifically ECT, IAT, etc. Except for the over 10 hour cold idle, it performs perfectly.

***Knailgun*** · 12-21-2005, 08:03 PM

Jeez SHawn, I'd hope you'd have a winter car by now......but the throttlebody is my guess man, see ya in the spring...hopefully

[SMAN] · 12-21-2005, 09:03 PM

Well i pulled it all apart right now. Not too muh gunk in there, but the deposites look like crudded oil. Probably not oil. So i used some cleaner and some pipe cleaners to try and clean everything out as best i can. The throttlebody is really nice and shiney on the inside now. But i feel like there wasn't enough crud in there to really be blocking it or making it stick. So i'll let it sit for a little bit and dry out, and i'll try making those test leads you made and see if i can't get it to turn properly and then put the whole thing back together and see if the car starts. I doutbt it's the ECU because if it was, the check engine light should be on.

redleg1one · 12-21-2005, 09:42 PM

My car would not start one day after it got real cold. It would kick over real strong, but would not start. Anyway, with a little help narrowed the problem to be the coil. Once I replaced it, it started right away.

[SMAN] · 12-21-2005, 10:28 PM

Nah the car starts but then instantly dies. I tested the solinoid for the ISC, it seems to be working ok, except that it doesn't FULLY fully close, there is like a sliver when i have it connected on way, a bit more when it's at rest, and it fully opens when i connect it the final way. So i'm going to package it all up and put it back together and make sure the hoses are on real tight anse see if it cold starts. Otherwise i might just have to drop it off at the dealership and see what happens.

[SMAN] · 12-21-2005, 11:20 PM

IT'S ALIVE!!!!!!!!!

Ok after putting it all back together, things must have worked cause the engine started 4 times in teh dead cold of this 17 degree freezing temp. The true test will be tomorrow morning, but i'm feeling optimistic. Thanks for the posts and to the outher countless threads that allowed me to peice together what was wrong.

Mike Gerber · 12-22-2005, 10:47 AM

Quote:

Originally Posted by [SMAN]

IT'S ALIVE!!!!!!!!!

Ok after putting it all back together, things must have worked cause the engine started 4 times in teh dead cold of this 17 degree freezing temp. The true test will be tomorrow morning, but i'm feeling optimistic. Thanks for the posts and to the outher countless threads that allowed me to peice together what was wrong.

Glad that your problem was solved. I just had the same problem on my 94 4 cylinder. Just yesterday I removed the snorkle to the throttle body and sprayed the square opening to the idle air control valve with throttle body cleaner. It was 18 degrees here this morning and the car started right up and held the idle at 1500 RPM. That little bit of oil you saw in there can get really thick and tacky as the temperature drops down causing the valve to stick. These deposits are actually a combination of oil and dirt. The EGR system recirculates the combustion gasses through the air intake plenum so that they can be reburned by the engine. This results in some oil and dirt being deposited into the plenum and the throttle body. That's why it's a good idea to clean the throttle body about once a year. I would like to caution the people who are spraying silicone into the idle air control valve that silicone can ruin the oxygen sensors. JerryR said it best; "Use an oxygen sensor safe solvent" only. You can use throttle body cleaner or carburator cleaner. They are designed to remove these types of deposits and are oxygen sensor safe. IMHO.

Mike