I have a '99 4Runnner 3.4 V6 with 62,000 miles that over the last year or so has become more and more difficult to re-start when it is at full-operating temp. If I drive 15 or 20 minutes, stop and the truck sits for 20-30 minutes, when I attempt to restart, the truck wont unless I use the gas pedal to get it to go. If I don't slightly depress the gas pedal, the truck will not start. This only happens when it's hot, once running it runs great. No issues with cold starting.

I’ve replaced the O2 sensor, cleaned the MAF, new fuel filter, spark plugs and air filter. All factory parts. Problem is still there any suggestions?

 

I have the same problem - been that way for probably 3 years or so, though I notice it when my truck sits for 5-10 minutes... like after I fill up at the gas station, or after I pickup my kids from day care... truck is at normal operating temp, I turn it off to fill up/pickup kids/whatever, try to start it, it cranks, catches, starts, then dies immediately, so it's nto like it's a starter/battery problem... more like a feul delivery problem. If I pump the gas pedal a couple of times (like I used ot have to do on my old carb'd car), it starts no problem.

I also have no problems with cold starts.

Here is a similar thread/problem from the Toyota Nation site... hopefully someone around here will be able to offer more/better advice than they did.

 

If you try starting it with the gas pedal fully depressed will it start fine?
If so you may have a leaky injector.

 

I've thought about injectors, but if I had a leak down problem I should have cold start problems also, correct??

Sometimes I have to hold the throttle about half open to get it to start and stay running.

Are all 3.4 injectors the same?

Thanks, Scott

 

Try cleaning your throttle body. It might be dirty which you had to release some power from the throttle body.

 

i have the exact same problem that yall are having also. mine has been doing this for about six months and i really do not understand it. i got a mechanic to hook it up to a computer thingy and it said that nothing was wrong with it. if you figue out how to fix it please let me know.

 

Same problem here too but I am also am having a problem when at WOT and I let off the gass the engine stalls out... like on the freeway... Needless to say I havn't stepped on it hard lately but could this also be related? I'm gonna clean the MAF, throttlebody and IAC this weekend probably and check back.
Kevin

 

Exact same problem here!!

Cold starting is fine... I drive it around a little bit, turn it off for 5-15 minutes and when trying to start I need to press the gas pedal down and rev it so it doesn't stall out!

Do all you guys have automatic or manual? Auto here.

 

My 2001 has hot/start problems sometimes. I suspect a vapor lock type problem. Some say it's not a problem with Fuel injection but I think it can be.
I am going to look at places where the fuel lines are close to heat etc.
Read this about the fuel pump/vapor lock.
http://www.forparts.com/ICtoyotafuel...rvice11.00.htm

 

i have an automatic

 

Auto here also. Has 122k on it and the only mod if it counts is a K&N. I could have overoiled it so I am gonna clean out the MAF first. There are a few threads that I have searched here but there doesn't seem to be a resolution. Maybe a bad TPS... which i might replace anyways. Idle is about 600ish
Kevin

 

clean your throtle body. i had the same problem couple month ago. then i went to the dealership, and they told me it was dirty throtle body. they wanted 130$ for this. I cleaned it by myself. It cost me 4$ and 20 minutes. after that no more problem with starting the engine.

 

Auto, Idle is around 600, I also had a K&N, cleaned the MAF and it seemed like it helped some but the prob is still there . I'm going to clean the TB tomorrow and see if that helps. If not I guess its a MAF. I've got no black smoke when it startes so I dont think its an injector leakdown.
Thanks for the help, I'll keep yall posted

 

Usually you would see some extra smoke with a leaky injector. It could be vapor lock but even that is not likely with a fuel injected motor because the fuel is held at a much higher pressure than with carb setups. I would also clean the throttle body well, check the function of the TPS, clean the MAF and clean the IAC valve.

 

I never had that type of problem but I would think you guys have a problem with TPS.
Should be easy to check with a service manual.
Just my $0.02.

 

I had this problem and after doing a ton of research, I found that the IAC is clogged. Once you take it and clean it the truck will start and stop fine (unless your IAC is damaged). I cleaned mine after I was having these same problems and my problem has gone away. The reason that you need to press the gas down in order to keep the truck running is beacuse the IAC can not adjust the ilde because it is dirty. I would suggest that you clean the IAC (which is located under the TB) and see if that helps the problem.

 

IAC? Not familiar with that term.

 

I think it is Idle Air Control it is located under the TB. Search IAC and you should find a ton of info on cleaning it.

 

It is the green piece in this pic under the TB:

 

never heard of it either.

is it circuts in there or what? Should you clean with electrical parts cleaner or what kind of cleaner?

That sounds like the right diagnosis for my truck too.