I would appreciate thoughts on how to handle the goal of getting the engine to warm up faster. I picked up a junk yard airfilter box from an old Cadilac Northstar for the specific purpose of directing heated air into the intake stream when the coolant is cold to help warm up the engine. The box itself works fine, and does the hoped for thing, but the problem is, when it opens up to cool air, it throws the computer into a tail spin. I have to program the warmup enrichment pattern to get richer at 165 degrees, which is apparently when the switch I purchased shuts off the valve that directs warm air to the filter, and opens to cold air.

Pierre gave me the idea of putting a solenoid into the vacuum line which is controlled by the ECM fan control. I could set it at any temperature to open, and at any temp to then close back up. I was t hinking of 195 to open, and then maybe 80 or so to close back up, which would be when the engine had really cooled back off.

The question is, if I have it open at 195, do you think it will still get squirelly when it opens to cold air? Do you think the sudden change in intake air temperature will still cause stumbinling and missfiring until it gets itself adjusted to the new AIT, but now just at a higher temperature, even though the engine is now more throughly warmed up.? OR, do you think that once the engine gets warmed up to it's operating temperature, it will handle this kind of change more gracefully?

Someone suggested that I do away with this warm up feature all together, which would simplify the tuning process. I am certainly open to that if I have to, but the faster I can get this engine to warm up, the more likely I am to drive it to work, which is only four miles away.

It is my understanfing that faster warmup is the reason all the manufactureres used this through the nineties. I don;t know if they do anymore, but I suspect some of them do. What do you think? Is this a silly concern. What do you think is the best way to handle the,apparently delicate transition from heated air to cool air. How do you suppose the manufactureres dealt with this problem? Do you think the engine will handle the changeover better at higher coolant temperatures? I hesitate to put time into another experiment if the bottom line is going to be I remove the control entirely, and draw stright from the cold air. all the time. I will keep the air filter box in any event. I had to cut the fender to fit it into a special boxed in space for it, where the battery used to be, and it wold be really simple to draw straight from under the fender for outside air. Thanks for your thoughts.
Sam

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I can't speak for all makes and models, but my 98 Dakota with a 5.2L ( 318 ) does not have any kind of prefheat for intake air. Air is drawn from the passenger side fender well, filtered and ducted directly to the throttle body. I believe the '05 Liberty is set up the same way.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

With the efi, I really doubt you need the preheat thingie...
But I would at least get it running properly without it first, and maybe figure that out later?

Cant you just rig up some kinda manaul valve (fish tank valve) to test out any possibilities of different temps helping it go threw the transition
( make it open when you want without spending money for test).

I totally agree with Rust Collector, you need to find ground 0 first ( it working properly without this before you try with it).

And if you cant get it to work right and still wish it to warm up quick you can always us timing & fuel to help this. Retarded timing & Rich fuel will build heat quick.


You really dont see Auto makers using this anymore. It was something to help get over a problem they couldnt control any other way. Now with the EFI systems as good as they are they dont have these problems anymore and really dont need them.

Just wandering does the car take a extreme amount of time to warm up. I to like to warm a engine before putting a load on it, it just makes sense that it would help in the wear of parts. But as far as it being able to run down the road before it warms this should not be a problem with the EFI. It should be able to pull out dead cold & drive right all the way threw the temp transition.

If all else fails and you still want this try to make it open slowly so it doesnt shock the system. Maybe some kinda of stepper motor that you could control to move it a little than a few degree latter move it a little more. Like the once on some of the heater control blend doors that have electronic heater controls.

Jess

There seems to be a consensus here that the warm air is not needed. Eliminating this feature would make it very simple to extend a 4 inch inlet right down through the bottom of the box into the open fender well.

It does not take long, for a slant, to warm up, but compared to my 4 banger Toyota it takes about twice as long. The toyota is warm in about 2 miles, and it takes 4 to warm up the slant. The engine probably weighs at least twice as much, if not more. The thing is, it is only 4 miles to work. It is always running cold if I drive it to work.
Sam

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LOL... That's why we always used to start our cars and let them warm up for 10 minutes (or 20 in the dead of winter) before we drove off. Of course, that's when gas was $.65 a gallon and air pollution was not a concern!



-Mac

Ok, seriously, are you using an electric fan or a standard belt driven fan? An electric fan would not turn on at first, so cold air would not be blowing across the block, perhaps shortening warm up time??

Also, along the lines of the "warm up" post, could you now add a remote car starter to it, since it is now an FI car?

-Mac

LOL, that would tend to live man a bit cold. I would expect a turbo slant would warm rather quickly, but it seems its not. Although I take that as a good sign that the engine is running quit clean and having a good burn rate that burns the whole cylinder worth of fuel. But running the timing as low as you can threw the warming transition could help to build heat. Mopar tends to be one that makes heat quickly. But even my big block wagon will not be fully warm in four miles if I dont let it heat some before leaving ( and it dont even have a fan on it, electric or manual) . So I am not sure what you will be able to do that will help more than giving it time to warm before leaving. Although late ignintion timing could help alot but I know you cant do this at idle. One thing I did think of, have you done enough plug reading to know you have the right heat range plugs in it. If they are to cold of a heat range this could contribute to not warming up good. But I would guage them more for the performance side of things than this, but still they could even be to cold for the performance tunning.


Jess

I am using an electric fan. It is controlled by its own seperate thermostat for now. If I forgo the idea preheated air, and go with routing the air directly from the outside, and then I could hook the fan relays up to the ECM output for that purpose.
Sam

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Sam,

Let's say you get rid of the box and just draw in straight outside air (which seems to be what manufacturers are doing, if I read the responses correctly).

That done, is your concern with the fact the engine doesn't warm up fully by the time you get to work...

A- worry that engine will suffer damage (like condensation in the oil)?
B- looking for personal comfort and a defrosted window?
C- all of the above

-Mac

It's just hard on a car to drive it cold. If it warmed up half way to work, then at least two miles of the driving would be spent maybe drying out the exhaust, and with the rings and bearings fitting each other correctly. I don;t have to drive it to work, but I was always proud of driving this old car into the work place. My piano shop is in an indutrial park that shares space with a Heat and AC install and maintenance shop. Those guys really appreciate seeing this old girl roll in once in awhile. Several of them have street rods, and dgrag cars and such, and it gives us something to talk about out in the parking lot. This picture shows the car sitting in front of the piano shop.

The box can stay. It contains the filter. It would just draw it's air right from the outside all the time. That is probably what I will do. I guess that will involve raising the warm up ratios to compensate for the cold air. We will be into winter here before too long, and then the car will just sit while I work on it. I have purchased a Rocky Mountain dash for it, and I will spend the winter getting that put together more than likely.
Sam

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What about a block heater so it's already fairly warmed up to start with?

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Now that is a pretty good idea. Anybody got any recommendations from the hinterlands up north? How about you Sandy? Do you use a block heater in any of your cars? Any brands to recommend or stay away from? Brilliant man!
Sam

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Coming from Vermont, block heaters are a slant's best friend!

I think I like the ones that go into an empty frost plug hole the best. They're simple, cheap, and effective. They're also less obtrusive in the engine compartment than the ones that mount in the heater hose, although those work OK, and some of them actually "pump" the heated water through the engine.

If I remember, much over two hours of preheating doesn't make a difference, so I always used a timer to come on at about 4:00 in the morning, unless it was going to be WAY below zero.

Sure makes starting easier in the winter!

-Mac

I live in minimal-snow-tah (minnesota) and we haven't had a real winter here in years, but I did really like the frost plug engine block heaters.

the pump ones were a great idea, but they went into the lines to the heater core, and it was pumping okay, but there is a ball in the end of its connection that prevents the coolant from going the other direction, so if you put it in according to the instructions (and the sticker arrow on the unit itself) the coolant can't flow to the core in its normal way, so you couldn't heat up the interior! once you realized the instructions were bogus, you could hook it up correctly, but it just didn't work that well. I ended up chucking the thing (it was an old model sold at "big wheel" years ago) and getting the block heater. much better model.