VAPOR LOCK

Thanks for the update TOMMY47. Great ifo. for others having the same issue.

:B

Good news, so far. Drove up I25 from Colorado Springs through Denver to Loveland.
Had a few long hills where I was in 2nd gear with the engine whining away and the temp gauge creeping up--No issues at all. Later at a traffic light in Loveland the temp spiked real high--again, no issues.
So far, it looks like the reflective tape shielding is doing its job.

Well, I don't have the expertise to start dismantling things 1500 miles from home, so I am not pulling filters now. I did wrap the fuel lines with a metal reflective tape that is supposed to prevent 90% of the heat from reaching the lines. Tomorrow, I'll find out.

j-d wrote:
Does that filter look like one of the ones in this pic? Proabably the uppoer one?




...snip...T-Bird, with early TBI, did not have a Mass Air Flow Sensor. It did have an Air Charge Temp Sensor in one branch of the Intake Manifold. It's a Thermistor, and a Cold Engine caused a High Resistance, which increased the Pulse Time to the Injectors, like Choking a Cold Engine. This was happening on the road, and the car would slow down, sometimes stop, in a cloud of black smoke. So rich it couldn't keep running. Not saying this is happening to you now, but it's a condition I ran into that sapped the engine's power.

Tbird didn't have MAF, but did have a MAP sensor with its speed density system. The ACT alone is not enough to throw serious fueling issues like what you are talking about. ACT is a "modifier" for existing fuel/spark tables and can only sway things a little each way...

Irregardless, I do agree with your comments about the fuel filter and it's ability to flow air when blowing through it. It was probably gummed up pretty heavily...

ReelTime wrote:
Tommy,
There was no overflow radiator tank on my unit and the water level in the radiator was (with the radiator cap removed, engine cold) around 2 inches from the top when full. The radiator itself was the expansion tank for that year model.

The "expansion tank" subject appears to have various opinions and different set ups on various vehicles.
Any cooling system benifits from haveing an expansion tank more accuratly called a coolant recovery system. It's possible that aftermarket body prep/rv vendors fail to reinstall the tank when thier work is complete. In any event you should make certain one is used even on older vehicles and stationary engines. If yours doesn't have a tank or has a tank where coolant level doesn't rise when hot and fall when cool,check the radiator cap. The cap must have a gasket rather than metal to metal where it contacts the filler neck. For best preformance,the tank should mount near level with radiator cap and of course be connected by leak proof hose. The tank automaticly purges air (same as manual proceedure explained above by Simplygib) on every heat cool cycle. Just add water if tank is less than 25% full when cool.
The benifit is less pump cavitation,no air bubbles insulating between liquid coolant and metal of engine and radiator which henders heat transfer.
I don't think this is the issue with Tommy's rig but is simply a link in the chain of cooling events that some might not be aware of.
However,I believe the overheating should be addressed first. The lose of power may very well clear up becaues we know a hot engine doesn't perform well.

Since you found the filter below the driver did you replace it?

Take it off and try to blow through it. Those filters were supposed to last 100K miles per the manual but mine was blocked with 11K miles. The big issue was not mileage but years. Most folks don't put many miles on an rv and they can get plugged just like carbs due to fuel varnishing.

I chased the same problem for a couple of years before the in tank fuel pump finally really started acting up and I had to replace it. Found that fuel filter plugged so bad I couldn't blow through it.

Hot days, hard pulls, both would cause vapor lock symptoms.

Does that filter look like one of the ones in this pic? Proabably the uppoer one?



The upper is "early model" like our 84 TBird and 97 Aerostar use. The lower one is from our 02 E450. Just as a note, either will replace the other, but the connections are different. Lower to replace Upper is OK, but Upper won't allow access to the disconnect tool (shown at right) once it's installed in a newer vehicle.

I took one of the old-type filters off the T-Bird and about couldn't blow through it. Red in the Face and enough air came out to blow a few bubbles. Tried a new one at the auto supply and I easily blew dust around on the floor. I can't prove it but I believe a restriced filter can wear down a fuel pump.

T-Bird, with early TBI, did not have a Mass Air Flow Sensor. It did have an Air Charge Temp Sensor in one branch of the Intake Manifold. It's a Thermistor, and a Cold Engine caused a High Resistance, which increased the Pulse Time to the Injectors, like Choking a Cold Engine. This was happening on the road, and the car would slow down, sometimes stop, in a cloud of black smoke. So rich it couldn't keep running. Not saying this is happening to you now, but it's a condition I ran into that sapped the engine's power.

If that canister does not have a filter installed in it, there should be a dip tube in its place that reaches down near the bottom of the canister. Make sure the dip tube is in place, or it will have a tough time drawing fuel up.

TOMMY47 wrote:
Also noticed that the last foot or so of fuel line was pretty close to the engine. Someone put about 1 inch of heat reflective tape on the line near the engine. I'll get enough reflective tape to cover that whole area and see what happens.

I would wrap this entire portion of the fuel line with some type of foam. Maybe some foam insulating wrap for a copper water pipe.