5.0 Idle issues

[monotonorobo]

Question, are the fuel hand and the low fuel connected? Because I’m “low” on the fuel hand but still no light. If they aren’t connected I suppose I’ll drive until it turns on.

[sly]

Basically, but the true E is typically the dot below the E and not the line angled to the E. The light doesn't come on until about 1/8 tank IIRC. And it will flicker at times due to slosh until it's low enough to not trigger above low.

[gadget73]

The light is driven off a module that is connected to the fuel sending unit. Its a bit of a dumb system but basically whats inside there is a bi-metal strip like the turn signal flashers use and its wound with wire. As the fuel level drops that wire makes more or less heat and eventually it closes the contact. I don't remember if it gets hotter or colder as the level drops but its an extremely simple system.

gauge accuracy is all over the place on these. bent arms and wonky senders affect it, but the instrument voltage regulator's output also messes with it. thats another dumb simple device that is exactly like a turn signal flasher. it opens and closes rapidly to get a ballpark average of 6 volts or something. Exactly what it ends up at depends on how tired it is. The gauge operates on heat, current flow through the sending unit causes it to swing one way or the other so the voltage being off or the sending unit being off, and the bi-metal bits being 40 years old all messes things up. They can also read a little different in extreme hot or cold.

If you really look into how these things work its amazing both how janky it is, and how reliable it is despite the jankiness.

[monotonorobo]

When I got off of work I tried to get the cover off but it got stuck on the headlight delay switch and I didn’t wanna break it after pulling it out so I came here to ask what was the right way to get it off. Also, new window motor gears came, anything else I should know before doing it tomorrow? I’m doing the front doors. I got the drill with my bits, grease, the caps that go inside the motor, and some dielectric grease for the connectors to the motors since they seem to act up from time to time.

[sly]

If you don't have a small notch on the back of the headlight knob that you can use a small scredriver to press a tab up into the knob that will release it, you need to press a button on the headlamp switch by reaching up under the dash to release the rod the knob is mounted on. I know the 88 I used to have had the notch so the knobs could be pulled off. The autolamp delay knob (secondary knob) should just pull straight off.

I think you're pretty much set on the window motors.

[VicCrownVic]

My experience is '90+ got the notched headlight knob. None of the pre-'90 cars I've worked on had the notched knob but I added one on my '89 CP.
I'm not sure the right way to reach that button, but I unscrewed the fuse panel and my arms are small enough that I reached up through there.

[sly]

My 88 MGM had the notch. So yeah... rather hit or miss in the later boxes.

[gadget73]

This is a Lincoln isn't it?

remove the woodgrain trim around the headlight switch
pull the screws holding the black bezel to the dash
the whole thing will come out and you can push the button in comfort rather than doing the blood-letting contortion BS.

if its a Ford or Mercury, sorry for your luck, the process is shit.

[monotonorobo]

It’s a 89 Mercury. I also wanted to confirm how much gas I had and when the gauge reaches the halfway point it will tell me how much I have correctly. I just filled up the tank w 9 gallons and the gauge moved to the full mark, and I reckon it’ll go back down to the actual level after a days worth of driving. Like last time.

[monotonorobo]

Was changing the clutch fan because coolant temp was like 218 other day on a hot day with AC on and it was 90+ out, didn’t overheat though. But I came across this. Seems the waterpump pulley is uneven and could have been the whining noise I’ve been hearing.

[monotonorobo]

Another pic… what’s the next step from here?

[Arquemann]

Looks like your belt is still tensioned, it's probably pulling the pulley crooked since you removed the bolts.

[sly]

Yeah... just the bolts being out. The pulley is not part of the water pump.

[monotonorobo]

Got it, heard someone say that the pulley came with the pump on the 302.

[gadget73]

It do

make sure the fan clutch pilots nicely on the water pump snout. It should slide on and have almost no wiggle. Some come with a bushing that you have to install, and if the bushing is missing its basically impossible to center the fan. That will beat the water pump bearings to death, make things vibrate, and will probably destroy the water pump. Scott had one break and send the fan into the radiator from that.