87 Toyota Camry idle dropping low only when the car is HOT

[david crevenston]

Hello to all,
Okay so my 87 Camry 2.0 5 speed (170K) has a serious problem of (ONLY WHEN THE CAR IT EXTREMELY HOT) when I turn the motor off and let it sit hot for about 4 minutes then it cranks/starts fine then immediately after that it dies. You can here that something is choking the engine even if the engine does start to idle it starts missing real bad and dies. Now to get the car running again all I need to do is give it a lot of throttle/gas when I start it up or turn the key off and let it cool down for a minute and then its good to go. So here is a list of what I have already done to fix the problem...... Inspected visually & physically all vac lines, cleaned EGR, EGR modulator, throttle body, and done complete tune up. I forgot to check the most simplest thing as this same problem happened on my 1990 Honda accord. Only when the car was extremely hot the main fuel relay would have the circuits separate and it would cause the car to crank and try to start but not continue to run. The EXACT SAME THING IS HAPPENDING WITH MY TOYOTA. So hence I think it may be the fuel main relay can someone please advise me as to where and if my 87 Camry has a fuel main relay and how to change it as well. Also there must be someone else on this forum that has experienced a similar problem with their 87-91 Camry please advise me here as I need some help with this one. The car is just not continuing to run after you try to start it when its extremely hot to me this means its being starved of fuel hence why I think the fuel main relay however that was the case with my HONDA and my Camry is different. So please advise me here if you think it might be something else or if the car has another relay for the fuel somewhere and if it is prone to going bad with heat and age please advise me thanks.

I forgot to mention sorry the distributor has been replaced within 1 year from advance auto a new (whole unit) distributor. Well if the distributor is new which it is whats the next suspect that you would check? Let me ask you this what would happen if the fuel filter, fuel pressure regulator, or the fuel pump were not working properly? Would any of these items cause the issues I am having ONLY when the car is extremely hot? Please advise thanks again for all your help now and in the past.
Dave

[RIP]

Maybe the IAC valve: http://en.allexperts.com/q/Toyota-Re...y-Low-Idle.htm

You can download your factory manual from the "Factory Service Manual" thread at the top of the forum.

[david crevenston]

Hello there,
Thanks for all that info. Funny you mentioned that because I just replaced the IAC a few days ago. I went to the junk yard and got a lower milage IAC from a 89 Celica (Same Motor 3fse) so hopefully that will fix the problem. The problem now is I can't test the car until its quite hot out at least 82f for it to duplicate the problem. So once it is hot out and I can test it properly I will report back if that fixed the problem or not.
Dave

[david crevenston]

Okay now I am getting very PERPLEXED HERE.... I tried a lot of stuff still the same problem I am running out of places/things to check on this car. I completed the job of cleaning & replacing the IAC that is NOT THE PROBLEM. The car is still doing the same thing. Now before I do anything else I will be asking many ? 's on here as I have done a lot of work for NOTHING..... Okay so here is my next suspect and question for you guys/girls. Would a dirty/clogged Fuel Filter cause/make the idle drop (only when car is hot) after starting the car when its hot? If a dirty fuel filter would not cause/make the problem with idle dropping then there is not point in checking/replacing it so please advise me on this question thanks. Next ? to all what do I check next I am running out of ideas on here guys PLEASE HELP.
Dave

[RIP]

Ya got me a little confused (not hard to do). In your first post you say the problem is there when the car is hot. In your second post you say you can't duplicate the problem until it's 82 deg out. So are you now saying your problem is dependant on outside temperature and not just the engine temperature???

Fuel pressure? First, I don't fix cars for a living. I fix cars as problems pop up just for the challenge and have been doing it for 30+ years. I don't recall working a hot stall problem. That said, generally a failing fuel pump causes lack of acceleration at speed or hard starts. I can't rule it out as the cause of your problem but there are other things I would look at first. I would connect a fuel pressure gauge and check the pump pressure before spending the bucks and time changing it. The filter? I would vote no but, it's an easy and comparatively cheap stab at the problem that wouldn't hurt either way especially if it hasn't been changed lately.

Before you spend weeks bangin your head on this problem and wish you had checked it to start with, read the factory manual and find the procedure to check for fault codes (if you havn't already). It involves jumpering two contacts on the test connector and watching how many blinks the check engine light gives you. You may not get anything or you could get a code that leads you to the problem in a hurry.

> You say you changed the IAC valve. Did you test to make sure it's getting a command to move from the ECU? Test procedure should be in the manual.

> High on my list would be a vacuum leak. They can be elusive. Take a closer look at the vacuum lines especially at or near the connections and for chaffing along it's length. I once had a leak in a line that could only be seen when pressurised under water. Spray brake cleaner (leaves no film) around the intake manifild gasket area with the engine running. If the idle bumps up when spraying a particular area, you found a leak. EGR is a vacuum hog. You've cleaned it but have you tested it? See the manual. The brake booster hose is often overlooked.

> Besides a vacuum leak I'm thinking engine temp sensor, air inlet temp sensor, O2 sensor, MAP/MAF sensor if equipped. They all deal with temperature. Test procedures shoud be in the manual.

> Fuel main relay? You guessed it...check the manual.

> http://www.aa1car.com/common_car_problems.htm Full of good info, includes topics on stalling and vacuum leaks. Also scan through the FAQs thread at the top of the forum. It's full of info. Lots of links to system background info.

I understand your frustration. I've been there many times. The good thing? I've learned a thing or two about cars and how they work in the process of fixing these contraptions. What you learn now will come in handy in spades in the future on any car.

[david crevenston]

Hello there,
Thanks for your help with this problem. Thanks also for getting back to me so quickly Let me clear up some questions for you on here.

No check engine light is on if there were any codes then my light would be on and let me know.


1st off car does not overheat new radiator, new coolant, hoses and is good. Camry have temp guage usually sitting 3/8 or right before it reaches the half way point after the car is warmed up and has been driven for a bit. That is what mine does same as other camry models like mine when it gets hot the dual fans come on to cool it and again the gauge stays near half way point only after the car is warmed up and has been driven some.
The car will do the following problem with this exact example. You drive the car for some time 20 miles for example does not matter city or highway what matters is the car is hot and at its normal operating temperature i.e. guage sitting @ 3/8 near the halfway mark. Then you stop in store come back out in less THEN 5 MINUTES and the car starts up then the rpms drop very low. Sometimes (it did this yesterday) also after rpm's drop the engine will die. This can be fixed by 1 waiting 10 seconds restart car or 2 start car then give a lot of gas. NOTE the car has never done the problem that I am describing above with the fans on. In other words after turning key to run position but before I start the car the fans will sometimes come on to cool motor. When I try to start it with fans on then the motor will not die. I can still hear it missing a bit but rpm's are up higher because that is what the car does anyways when the fans come on. MORE AND MORE I am feeling/thinking this problem is fuel related and is bad. Here are some more ? 's for you sorry for so many but I have no choice.....
What would happen if the engine coolant temperature sensor is bad? I think if it were bad then it may be out of range and not telling the computer the car is hot. This could produce an excessivley rich mixture for a hot engine? What do you think am I correct? If I am correct about above then it should be looked into please advise me thanks.
What does the fuel pressure regulator do? If it were bad could it cause the problem I am describing the car not starting only when hot? Thanks for your help in this matter.
How can I test the system to see if the coolant is circulating in the system?
Thanks for your help in all these questions and with this matter. Oh BTW I changed spark splugs today and one was bad it had the tip where you measure gap touching the plug so that can't be good. Color was okay a little hot (white) but not too bad. Could some bad plugs cause the problem described above? Thanks for all your help
Dave

Originally Posted by RIP

Ya got me a little confused (not hard to do). In your first post you say the problem is there when the car is hot. In your second post you say you can't duplicate the problem until it's 82 deg out. So are you now saying your problem is dependant on outside temperature and not just the engine temperature???

Fuel pressure? First, I don't fix cars for a living. I fix cars as problems pop up just for the challenge and have been doing it for 30+ years. I don't recall working a hot stall problem. That said, generally a failing fuel pump causes lack of acceleration at speed or hard starts. I can't rule it out as the cause of your problem but there are other things I would look at first. I would connect a fuel pressure gauge and check the pump pressure before spending the bucks and time changing it. The filter? I would vote no but, it's an easy and comparatively cheap stab at the problem that wouldn't hurt either way especially if it hasn't been changed lately.

Before you spend weeks bangin your head on this problem and wish you had checked it to start with, read the factory manual and find the procedure to check for fault codes (if you havn't already). It involves jumpering two contacts on the test connector and watching how many blinks the check engine light gives you. You may not get anything or you could get a code that leads you to the problem in a hurry.

> You say you changed the IAC valve. Did you test to make sure it's getting a command to move from the ECU? Test procedure should be in the manual.

> High on my list would be a vacuum leak. They can be elusive. Take a closer look at the vacuum lines especially at or near the connections and for chaffing along it's length. I once had a leak in a line that could only be seen when pressurised under water. Spray brake cleaner (leaves no film) around the intake manifild gasket area with the engine running. If the idle bumps up when spraying a particular area, you found a leak. EGR is a vacuum hog. You've cleaned it but have you tested it? See the manual. The brake booster hose is often overlooked.

> Besides a vacuum leak I'm thinking engine temp sensor, air inlet temp sensor, O2 sensor, MAP/MAF sensor if equipped. They all deal with temperature. Test procedures shoud be in the manual.

> Fuel main relay? You guessed it...check the manual.

> http://www.aa1car.com/common_car_problems.htm Full of good info, includes topics on stalling and vacuum leaks. Also scan through the FAQs thread at the top of the forum. It's full of info. Lots of links to system background info.

I understand your frustration. I've been there many times. The good thing? I've learned a thing or two about cars and how they work in the process of fixing these contraptions. What you learn now will come in handy in spades in the future on any car.