2.8 "Dieseling" When Turning Off

[ford4wd08]

So, I went ahead and installed a 160 degree lower thermostat this morning. Been meaning to it for a while.

I pulled a plug from each back just to see how the tune is. Seems to be great.

I've lowered the idle down for now. I believe that is the majority of the issue.

Did out a little water down the carb, I don't have a cat, so no issue there.

I'll keep an eye on it, just for reference what should idle be with the AC running? Assuming I have a solenoid to raise it?

 

[19Walt93]

Why a 160 thermostat? The Thermostat controls the lowest temp the engine will operate at, not the highest. I'd like to see at least a 180 in there.

 

[ford4wd08]

Why a 160 thermostat? The Thermostat controls the lowest temp the engine will operate at, not the highest. I'd like to see at least a 180 in there.

It was recommended on here a while ago. That sets operating temp to 180ish because it is a lower thermo stat housing on the bottom hose of radiator.

I ran a 180 in the lower and it was running a little hotter than I liked with AC on in the summer. Hovering over 200. Probably not the worst, but I like it to operate lower.

I can always change it back to another temp if I need too. I wish they made a 170 I could find. I would prefer it.

 

[ford4wd08]

We covered the stat location and temp back in this thread.

Temp Gage Quit Working

If you have the IR temp reader then test the upper and lower hose, should be about a 20deg difference, after warm up And test it with RPMs at say 1,500 and at idle

www.therangerstation.com

 

[ford4wd08]

Haven't had any trouble since I turned the idle down with Dieseling, hopefully that will keep it at bay.

In the mean time I've done a little more research on solenoids for the carb.

I found what looks to be what Ford used on the 2150 carbs as "idle stop" so I went ahead and bought one on eBay.

MOTORCRAFT 2150 CARBURETOR SOLENOID & BRACKET FORD CARS TRUCKS MERCURY V8 ENGINE | eBay

Curious if Ford used it as an actual idle stop or as idle increase when AC was activated. I hoping I have enough adjustment that I can use it to only work when the AC is on to hold the idle up a little more. Any idea what I should target for idle when the AC is running?

Also found a quick note on another site about the 2150 and better picture.

Motorcraft gurus?? - Full Size Jeep Network (fsjnetwork.com)

I know the full size jeeps guys had motorcraft/autolite carbs on a lot of their v8's from the factory.

 

[RonD]

This is a good read, with pictures, on the 2150's: http://grantorinosport.org/bubbaf250/carb/carb02.html
Look at both pages

 

[ford4wd08]

This is a good read, with pictures, on the 2150's: http://grantorinosport.org/bubbaf250/carb/carb02.html
Look at both pages

I forgot about that page. I have looked over it in the past. I'll look through it again.

I guess I never realized you could have a dashpot and solenoid in the same assembly like in the one pictured on that page.

 

[superj]

back to the carbon build up. i just put the hose in the carb/throttle body. you can also use transmission fluid, or whatever cleaner you want but you will be fogging out the whole neighborhood and killing all the mosquitos down wind.

alot of jeep guys switch to 2100 and 2150 carbs on the 4.2 jeeps also. i tried them but never had great success so i went to a holley four barrel from a 65 mustang. your motorcraft might even say holley inside the bowl somewhere.

 

[ford4wd08]

Why a 160 thermostat? The Thermostat controls the lowest temp the engine will operate at, not the highest. I'd like to see at least a 180 in there.

Decided to check the upper radiator hose today after driving home with the AC on and letting the bronco idle for a minute in the driveway for a bit. 76 degrees outside.

I'm pretty happy with around 190 degrees and can only imagine it will be slightly warmer when the temps are up in the summer.

It did tend to run warm when I would be in a Drive thrus and all before, so maybe this will help with that too.

Anyhow just thought I would provide data for anyone with lower thermostat still (all 3 of us lol)

 

[RonD]

If it runs warmer at idle and then temp drops down when driving above 25mph the radiator is OK but the fan is not, or water pump impeller blades are very worn

Fan's sole and only purpose is to pull air thru radiator when under 30mph
And the shroud, shroud prevents fan from pulling air in from the sides, so all air comes thru radiator, cooling it


Ford's temp gauges are set for approx. 205deg at 1/2 way
Just below 1./2 is where it should be after warm up, and then just above 1/2 pulling a load or going up along grade
1/4-1/3 is too cold, you are wasting money on fuel, same as running with the Choke on
185-195degF is a good coolant temp, it means engine metal is getting hot enough to clean the oil as it passes thru the system, burns off "fuel", condensation and other contaminants


SAE(society of automotive engineers) did a study in the late 1960's, 1970's, they found that, yes, 185-195degF was best temp for engine efficiency and oil cleaning
That was when car makers switched to 190-195deg T-stats from the "standard" 180deg, that were used for so long

Nothing wrong with 160deg or 180deg t-stats, just costs you more money in fuel and shortens the life of the engine

 

[ford4wd08]

If it runs warmer at idle and then temp drops down when driving above 25mph the radiator is OK but the fan is not, or water pump impeller blades are very worn

Fan's sole and only purpose is to pull air thru radiator when under 30mph
And the shroud, shroud prevents fan from pulling air in from the sides, so all air comes thru radiator, cooling it


Ford's temp gauges are set for approx. 205deg at 1/2 way
Just below 1./2 is where it should be after warm up, and then just above 1/2 pulling a load or going up along grade
1/4-1/3 is too cold, you are wasting money on fuel, same as running with the Choke on
185-195degF is a good coolant temp, it means engine metal is getting hot enough to clean the oil as it passes thru the system, burns off "fuel", condensation and other contaminants


SAE(society of automotive engineers) did a study in the late 1960's, 1970's, they found that, yes, 185-195degF was best temp for engine efficiency and oil cleaning
That was when car makers switched to 190-195deg T-stats from the "standard" 180deg, that were used for so long

Nothing wrong with 160deg or 180deg t-stats, just costs you more money in fuel and shortens the life of the engine

I have a feeling the water pump might need to be replaced at some point, but the flow seems to be ok for now. I have a NOS one on the shelf, but have yet to install it.

The radiator is new as is the fan clutch. Shroud is in place.

I'll drive it for a while see what happens. I'm getting terrible mileage from my short commute to work as it is.

It is slower to warm up because of the lower temp thermostat of course, but seems to be working well.

I always assumed and thought I was told the cooling system on the early Bronco 2 and Ranger was marginal at best from the factory.