Runs good for 20 minutes, then dies and won't start until the next day

[jdmccright]

Check the ECT sensor, EGR and IAC valves, and look for vacuum leaks.

[toyota2]

i had a similar problem with my truck. im prety shure that your alternator is going out. you should take your alternator out and take it to autozone and have them check it. they do this for free.
your truck will run on the juice from your battery antil their isnt enough juice to fire your spark plugs in turn leaving you without enough juice to start your truck antil the battery has had enouph time to regain a little charge. this is why you have to wait till the next morning to start it again. and if you drive it to offten this way your battery will go bad on you as well.

[tblake]

Originally Posted by whoaskew

...I did notice that the passenger side valve cover has an opening in it where something obviously is supposed to be sticking in there. Would that be for the pcv valve? Could that be related to the engine dying on me?

I would look into this as it could be a large vacuum leak if it is the PCV system. Do you have a picture you could get for us? It sounds like the PCV system to me.

[whoaskew]

Originally Posted by tblake

I would look into this as it could be a large vacuum leak if it is the PCV system. Do you have a picture you could get for us? It sounds like the PCV system to me.

Here is the picture of the passenger side valve cover with the air cleaner removed. Do you know what goes in the hole? Could that be related to the engine dying on me?

[whoaskew]

Originally Posted by whoaskew

Here is the picture of the passenger side valve cover with the air cleaner removed. Do you know what goes in the hole? Could that be related to the engine dying on me?

The guy at the auto parts store told me that was for the PCV valve, so I bought it and put it in, but the car still died after 20 minutes.


My tailpipes are kind of rusty, so I guess the next thing I will do is take the truck to the muffler shop to get chrome tailpipes extentions. I figure while I am there, I can have the guy check to see if the catalytic converter is clogged, like the other poster suggested I do.

Is there anything else I should try to do myself first?

[tblake]

That hole is for the PCV system on my 97 for sure, and I am pretty sure it is the same for yours.

Here is a picture, you are missing a vacuum hose off the bottom of your throttle body, and the PCV valve.

This is the best picture I could find. Thanks Google Images.



Missing these parts would cause a HUGE vacuum leak at the base of the throttle body.

I'd just like to know where they could have went.

[tblake]

Never mind, I see in your picture that the PCV hose is there, its just you are missing a PCV valve and a 90 degree elbow. Either way it will cause a HUGE vacuum leak and needs to be fixed before we try and diagnose any further on this die/no start when warm issue.

[whoaskew]

Originally Posted by tblake

Never mind, I see in your picture that the PCV hose is there, its just you are missing a PCV valve and a 90 degree elbow. Either way it will cause a HUGE vacuum leak and needs to be fixed before we try and diagnose any further on this die/no start when warm issue.

Yes, I went ahead and purchased a PCV valve and installed it. Unfortunately, I didn't notice any difference as the truck still died after 15 - 20 minutes.

[whoaskew]

I sat in the driver's seat today and noticed the temperature gauge was in the red even though the key was not in the ignition. In fact, I haven't even started it today. It did not overheat yesterday when I ran the truck after putting in the PCV valve.

jdmccright suggested my problem may be the coolant temperature sensor. I went ahead and purchased it since it was only $11. I think I will be changing it first before I try anything else, as soon as I can find a diagram to show me where to find it.

[jdmccright]

It is screwed into the intake manifold just to the left of the upper radiator hose water neck with a 2-wire connector.

The missing PCV would not cause a no-start. It would cause the truck to run rich...and make a messy valve cover.

[whoaskew]

Originally Posted by jdmccright

It is screwed into the intake manifold just to the left of the upper radiator hose water neck with a 2-wire connector.

The missing PCV would not cause a no-start. It would cause the truck to run rich...and make a messy valve cover.

OK, just changed the coolant temperature sensor, started it up, and it still died after about 15 minutes. Any suggestions on what to try next?

[whoaskew]

Originally Posted by 2000CAYukon

I wonder if the cat is plugged. You should remove the 02 sensor from the exhaust manifold and try to start it.

//2000CAYukon

I think I narrowed down the problem. I removed the oxygen sensor as you suggested and it ran for over 20 minutes without dying.

Of course, error code 13 popped up since I had the oxygen sensor unplugged, but that was expected.

I put my hand near the tailpipe and felt warm air blowing on it, so does that mean the converters are not clogged?

I already bought the O.E. Bosch 02 sensor from Autozone for $20, but the engine is too hot right now to put the new one in, so that'll have to wait until the morning.

[2000CAYukon]

Is the PCV hoses connected to the front of the TBI unit? Hard to tell from the picture.

The cat could be clogged or you are having an issue running in closed loop.

//2000CAYukon

[whoaskew]

Originally Posted by 2000CAYukon

Is the PCV hoses connected to the front of the TBI unit? Hard to tell from the picture.

The cat could be clogged or you are having an issue running in closed loop.

//2000CAYukon

Yes the PCV hose is connected to the TBI. There is a plastic tube with hoses on both ends of it. One of the hoses is 90 degree angle hose going from the plastic tube to the bottom front of the TBI, and the other straight hose is going from the other end of the plastic tube to the PCV valve.

[whoaskew]

With the o2 sensor unplugged from the electrical connector and unscrewed from the exhaust manifold, the truck ran over 20 minutes without dying.

Today I installed the new o2 sensor in the manifold and plugged it into the electrical connector and started it. The truck died again after running for 20 minutes.


When the truck dies, I know that the injectors are still squirting gas, and I still have spark at each wire. Remember that I have no check engine codes on the dash, except of course when I unplugged the o2 sensor. I believe that my problem is either a clogged catalytic converter or I suspect that the computer is incorrectly adjusting things which makes the truck die when it goes to closed loop.


My new plan is to keep the sensor installed in the manifold, but unplugged from the electrical connector. I believe that if it will run like that, without dying on me after 20 minutes, that would indicate that my catalytic converter is not clogged up.

Then, I will at least know if the problem is exhaust related or if it is something else.

Any other suggestions?