[Tazbear]

Anyone have the answer to these two questions:

1. Will hot outside temperatures affect a possible failing MAF sensor?

2. Will hot outside temperatures affect a catalytic converter?

Car is hesitating and surging ONLY when outside temp is above 85 degrees. Every sensor (and I mean EVERY sensor) has been replaced, new O2 senors (front), new plugs and wires. Only three things left and that's the MAF sensor, the converters and the fuel pump (dealership thinks the pump may be overheating due to excess temps from asphalt.

Many thanks!!

 

[stodge]

Forgive me for dredging up an old post, but could someone please answer these questions? They may relate to my problems, and even if they don't, I'll still learn something today.

Thanks

 

[Damon]

Hmmm. Ill say what I know.

Fuel pumps are electrical devices and they do get hot. Thats why its always good to not let your gas level go below 1/4 tank, as the gasoline acts as a coolant for the pump, and the coolant helps the pump work less harder.

Usually when a fuel pump is on its way out, it makes a loud humming noise.

Thats all I know, im sure someone else will chime in.

-DC

 

[Nidan]

Originally posted by Damon@Jun 17 2005, 11:48 AM
Hmmm. Ill say what I know.

Fuel pumps are electrical devices and they do get hot. Thats why its always good to not let your gas level go below 1/4 tank, as the gasoline acts as a coolant for the pump, and the coolant helps the pump work less harder.

Usually when a fuel pump is on its way out, it makes a loud humming noise.

Thats all I know, im sure someone else will chime in.

-DC

Ya, what he said... fuel pumps tend to act up more when it's hot and they're wearing out... have the fuel pressure checked when the car is hot, especially after a long drive in hot weather.... that'll tell ya if the pump is crappin out... as for the MAF, i've never really heard of temps makin a difference.. same with the cats.. they get super hot anyway, so the outside temp isn't really gonna have much bearin on them. They in fact are designed to work their best when they're hot.

 

[stodge]

Would a dying fuel pump cause surging, hesitation, performance loss, speed and throttle fluctuations when cruising and fluctuations of all of the above? I thought the cat converter might be clogged but I don't notice any smells.

 

[sfontain]

Originally posted by stodge@Jun 17 2005, 01:00 PM
Would a dying fuel pump cause surging, hesitation, performance loss, speed and throttle fluctuations when cruising and fluctuations of all of the above? I thought the cat converter might be clogged but I don't notice any smells.

I wouldn't think surging unless the surging is preceded by ungodly poor performance, because the fuel pressure regulator shouldn't allow for fuel surges in the engine. But yes hesitation, performance loss, acceleration fluctuation.

You also should change your fuel filter if it's been a while. And when was the last time you had your plugs and wires changed?

 

[stodge]

Yes I have ungodly poor performance, especially uphill and/or when the car is loaded. The heavier the load (2 people, 3 people, 4 people, 3 people with luggage e.g.) the worse it is.

The fuel filters, plugs were changed I thikn within the last 6 months? We've done 5000m in that time.

Taurus 2000SE Vuclan, 54000km.

Unless there's a carbon build up in the engine.

 

[holedigger]

Ah, carbon -- the old scapegoat. That's not very likely, especially with such a new engine.

More likely would be a vacuum leak or fuel problem. Also install a new air filter if that hasn't been done.

 

[stodge]

Could the fuel injector be to blame for my problems? I briefly spoke to a mechanic at a Ford dealership and that was his suggestion. From what I've read, I don't see how it can be that.