94 Taurus Engine stalls after a long trip, why?, Please Help!

please respond to me directly, thanks neil

Why would you want people to respond in email? the idea of this newsgroup is to have things posted publicly, so that others can also learn and/or use the information.

yes I fully understand that, I don't always have acess to this newgroup and a response is very important to me at this time. If they want to respond to both, so much the better.

If it is that important to you, you will obtain access to the newsgroup. You can access it at google groups. And your local library should have computers connected to the internet.

Jeff

It could be overheating.

I had the same problem when I forgot to put coolant back in my old 289 after putting a different pair of heads on it. The heads had large chambers so compression was lower and I expected power to be lower. So I ran the car for a week with virtually no coolant. The overheat light never triggered because I accidentally broke the sender (it was a bad day). Anyhow, running on teh highway it was gutless. Stopping for a toll booth it stalled and didn't wanna start. Took me a minute to get it started again and then it ran alright once I got moving again. Finally I remembered I forgot to fill the coolant system so I pulled over and filled it. Problem solved. More power and didn't run rough or stall. Of course I had gone a few hundred miles with no coolant already, but no harm was done. Those 289s sure are tough little engines!

So, make sure your coolant system is full and your thermostat is working. Also, you may wanna check that your temp sensor is working and your overheat light bulb is not burnt out or otherwise non-functional.

An engine can overheat for several reasons other than that, such as retarded timing, malfunctioning fan, malfunctioning EGR valve, I suppose O2 sensors could cause it as well.

Anyhow, it's just something that may be worth checking.

Cory

cory explain how an egr o2 sensors could cause itvto over heat

lmfao

hurc ast

Bad catalyic convertors can cause the engine to overheat because most of the heat is removed by the exahuast, and if the exhaust gas doesn't leave as fast, the heat stays behind.

Jeff

If the exhaust does not leave the engine can not take in fresh air. Because of the lack of oxygen fuel does not burn. Because fuel does not burn no heat.

That sounds good on paper but it's not really true in the real world. Think in terms of really bad efficiency, throttle at 50 or 75% just to maintain speed and the trans will probably be in 2nd or 3rd instead of OD. Soon things are smoking hot. Bob

I apologise. I was not clear enough. I meant if the catalytic constricts the flow of exhaust without completely blocking the outflow. The heat doesn't leave the engine as fast, causing overheating.

Jeff

It will still not overheat the engine, simply because there is less oxygen fuel is not burning completely, less heat. If the cats can still do there job some what they may get real hot but the engine is starving and will not. The engine will be simply very low on power and act very much like it's running out of fuel at higher RPM's and under load.

The engine even wide open will act just like it's running out of fuel. You wont go any where. It's not only good on paper but it's a fact because of the basic laws of science.

(...)

That's news to me. A bad catalytic convertor doesn't cause the fuel to burn incompletely.

I believe you are the resident troll, but I don't recall so I'll explain anyway. A malfuctioning EGR system can lean out the mixture. A malfunctioning O2 sensor may result in giving an false rich reading, the computer will compensate by leaning out the mixture. A leaner mixture burns hotter, raising combustion chamber temps and thus the temperature of the entire engine. Also, an excessively lean mixture can burn holes in pistons and do some real nasty damage.

Cory

The EGR gasses displaces the oxygen, so in effect the mixture is not lean. There is less oxygen to support combustion.

The mixture that the ECM provides will never get to that point.

It's very simple. If the exhaust pressure is high the cylinder can not expel all of the exhaust. If the exhaust system is plugged, where is the exhaust going to go? No where it stays in the cylinder. Meaning you can not take in more fresh air because the cylinder is already partially full or full. An engine in that condition will have low vacuum and will run like its running out of fuel under load and higher RPM's. It's basic science.

And the heat won't be leaving the engine in the exhaust, either. It is basic science.

How do you burn fuel with out oxygen? A plugged exhaust will not cause an over heat.