hi just wanted to know why my tj magna takes so long for the idle to drop in the mornings,, have to warm it up for a while cause the ilde wont drop from 1000rpm when cold please help me
what can it be???:tired:

Sounds normal to me.
I suggest 30-60 seconds is sufficient time to idle a cold motor and then just drive it gently until it has reached normal operating temperature. Driving it gently will warm it up quicker rather than idling.

This is built into ECU, it will idle above normal while engine is cold..... It will drop to normal pretty much as soon as your temperature gauge starts to move up.

My tj idles at 1200 with climate control off for atleast 1 minute then settles about 600.

What can it be? It can be normal! lol

Mine does 1,500 rpm at start on a cold morning. I usually drive off straight away, idle is normal at the first traffic light I stop at. Waiting for the idle to settle to normal is just wasting petrol and time.

Wonder why a cold idle is so high? Simple! Any slower will cause condensation of the fuel onto the cold cylinder walls, and the engine would stall when you lift off at the first corner you come to. Then you have no power steering, and possibly no brake boost. Not fun.

[A lot of people never drove a car with a manual choked carby, evidently.]

Always drive off as soon as starting a car if possible, its not ideal to leave a cold engine idling for a while before intending to drive it

Always drive off as soon as starting a car if possible, its not ideal to leave a cold engine idling for a while before intending to drive it

Good idea. Petrol condensation washes oil off the cylinder walls, best driving straight off and get the engine up to working temperature quickly (but gently) to reduce wear.
My TJ runs down the road at 25 KPH (downhill) just on the cold idle speed. I'd be wasting that petrol if I just sat there warming it up. With my TJ the reverse and first gear engagement are quite gentle, even at the higher cold idle. My TS in comparison engages with a thump, I usually wait 20 to 30 seconds before I drive off.

Is that true? Dam I've always waited 20 seconds before driving off to let the car settle

Is that true? Dam I've always waited 20 seconds before driving off to let the car settle

Horses need to settle before you set off, cars don't. lol Start it, seat belt on, off you go (gently).

No, honestly, "warming up" a car was done in the old days, to get the low pressure oil pump to push the thick oil to the top, and to prevent stalling when you drive off. Not needed anymore.

Nostalgia time: I used to start my old HX Holden up with full choke, then push it in gently as the engine ran smoother and the revs went up. Even with a warm up, pushing the accelerator too far down would cut the engine out altogether. It was a 202 red motor, first of the emission controlled engines. Enough said.

I had a carby fiesta with manual choke too lol

Horses need to settle before you set off, cars don't. lol Start it, seat belt on, off you go (gently).

No, honestly, "warming up" a car was done in the old days, to get the low pressure oil pump to push the thick oil to the top, and to prevent stalling when you drive off. Not needed anymore.

Nostalgia time: I used to start my old HX Holden up with full choke, then push it in gently as the engine ran smoother and the revs went up. Even with a warm up, pushing the accelerator too far down would cut the engine out altogether. It was a 202 red motor, first of the emission controlled engines. Enough said.

Yep, manual choke lol

Couple a pumps of the accelerator, choke fully out for crank, choke half way in immediately after engine roars into life, down to the end of the street & push choke in more, after about a minute or 2, push choke all the way in. I miss the old days... lol

I had a carby fiesta with manual choke too lol

Them were the days! None of that fancy EFI, ECU stuff in those days! And only RICH people bought automatics! Driving was a real skill then! lol

By the way, remember buying and replacing IGNITION POINTS on a regular basis? lol (No, if you are under 50 you won't. lol)

My first mod: putting a BOSCH BLUE coil on my '64 VW. Extra 10 HP at least! lol

Youre not wrong. Sometimes the only "power-everything" was me pushing the ****ing thing down the street to jump start it. Those were the days.

Or the auto station search on the tape deck

By the way, remember buying and replacing IGNITION POINTS on a regular basis? lol (No, if you are under 50 you won't. lol)

Bah! Who needs an electronic distributor lol


Or the auto station search on the tape deck

You had a tape deck... now that's high tech. AM radio if you were lucky!

it take maybe 3min to get it to at least to 1000rpm
i can never just start it and go i have to sit on it for a while and then it s a bit smoky

Good idea. Petrol condensation washes oil off the cylinder walls, best driving straight off and get the engine up to working temperature quickly (but gently) to reduce wear.
My TJ runs down the road at 25 KPH (downhill) just on the cold idle speed. I'd be wasting that petrol if I just sat there warming it up. With my TJ the reverse and first gear engagement are quite gentle, even at the higher cold idle. My TS in comparison engages with a thump, I usually wait 20 to 30 seconds before I drive off.

great info

thanks amigo let u know after i give a go tomorow morning,,, thanks :)

Warming up prior to driving does have a benefit, oil flows better when hot thus flowing better through the engine, when you drive your rpms are generally higher then idle, hence you get more rotations of the engine with colder oil = more wear on start up, i had my car 11 years now, never drove it cold.

While yes whether effect of such wear might not show itslelf for the life time of the car never less warming up does have a merit.

Warming up prior to driving does have a benefit, oil flows better when hot thus flowing better through the engine, when you drive your rpms are generally higher then idle, hence you get more rotations of the engine with colder oil = more wear on start up, i had my car 11 years now, never drove it cold.

While yes whether effect of such wear might not show itslelf for the life time of the car never less warming up does have a merit.

You could argue that low rpm means the oil isnt curculating as fast around the engine when its idling...

You could argue that low rpm means the oil isnt curculating as fast around the engine when its idling...

I agree, it might be, really no way of knowing, like i said effect of such wear probably will never show anyhow so really it doesnt matter

10W-40 weight oil is really thin when cold, and with the high pressure pump on the Magnas, the oil gets to the top of the engine - rockers, cams - real fast. Take the oil cap off the engine, shine a torch down there, get someone to start the cold engine, and count how long it takes for the oil to start spraying around. It's only a second or so.

Now with an old engine, with 30-40 grade oil, it is a different story.

I prefer to warm the car up if nothing else on a cold day to get the heater nice and warm and on a hot day to get the cold air circulating. Either way it wont hurt the car.

Horses need to settle before you set off, cars don't. lol Start it, seat belt on, off you go (gently).

No, honestly, "warming up" a car was done in the old days, to get the low pressure oil pump to push the thick oil to the top, and to prevent stalling when you drive off. Not needed anymore.

Nostalgia time: I used to start my old HX Holden up with full choke, then push it in gently as the engine ran smoother and the revs went up. Even with a warm up, pushing the accelerator too far down would cut the engine out altogether. It was a 202 red motor, first of the emission controlled engines. Enough said.

Not quite. The main reason pod motors were warmed up was because the technology with metals etc was not great, it allowed for more even and slower expansion

With the magna, the fast idle when cold has nothing to do with the ecu, it is controlled by the air bypass valve on the tb, similar to a thermostat,as the motor warms up the passage closed and less air means slower idle

Again has jack to do with stalling and condensation, is because a warmer motor burns cleaner thes fast idle willbwarm up the motor faster thus less pollution

Speaking of idle, I usually fire it up, find my sunnies, chuck some chewie in the mouth and break out the chap stick before chucking it in drive. This is about 60 seconds or so depending if I'm in a rush.

I have read that it's not a good idea to race the engine when cold which seems fair enough. However, after pulling out of my driveway, there is about 100 metres of road before you have to turn onto a busy 80km/h road. Now, unless I'm really early or running crazily late and have missed the school rush, my only chance is to punch it into traffic, between 50% and 100% throttle and hope for the best. (not quite litterally but you get my drift)

I'm doing this every morning unless theres a huge ass break in the traffic and I can dawdle up to 80. Am I going to cause expensive damage by throttling on cold? It's garaged every night so it's (hopefully) not full of condensation or anything.

Nah I doubt you'd be doing any damage, the internals warm up fairly quickly. Those 60 seconds and the 100 metres of road should be sufficient enough to move the temp gauge? As long as you're not flogging it past 5000rpm straight out of the driveway

I've always thought to warm the engine up first. I do it every morning for about 10 minutes (unless I'm at the missus house and need to gtfo before her dad wakes up). My theory was that the engine does fewer revolutions at a lower idle, hence not running cold oil through a fast rotating engine.

I read this a few years ago. Dont know if you guys have ever herd him talk, but he knows his stuff. I trust him.

http://www.abc.net.au/science/articles/2007/09/27/2044311.htm

Nah I doubt you'd be doing any damage, the internals warm up fairly quickly. Those 60 seconds and the 100 metres of road should be sufficient enough to move the temp gauge? As long as you're not flogging it past 5000rpm straight out of the driveway

Oil temp has nothing to do with coolant temp. always drive for 10-15 minutes before giving it a bootful. Revving a cold engine hard is a realy easy way to shorten its life span.

Most new cars reduce the rev limit to 4000-5000 rpm until its warmed up enough.

Oil temp has nothing to do with coolant temp. always drive for 10-15 minutes before giving it a bootful. Revving a cold engine hard is a realy easy way to shorten its life span.

Most new cars reduce the rev limit to 4000-5000 rpm until its warmed up enough.

Plus 1 for this!

I was reading the owners manual for our 96 pajero the other day. It says when cold, the gearbox is limited to 3rd gear until its warm.

I read this a few years ago. Dont know if you guys have ever herd him talk, but he knows his stuff. I trust him.

http://www.abc.net.au/science/articles/2007/09/27/2044311.htm

Great article, thanks.

Further to this, a number of user manuals for all variety of cars state "always drive a car immediately after it is started, never let it idle from cold". Pretty sure my dads Outlander user manual states this clearly. The V6 in it is closely tied to the 6G7x series engines so i imagine it would also apply

Plus 1 for this!

I was reading the owners manual for our 96 pajero the other day. It says when cold, the gearbox is limited to 3rd gear until its warm.

I read that the Magnas do this to? Might have been the manual or service manual or maybe I was dreaming. All I know is I went for a drive and it dropped into 4th happily ???

Some comments in this article though..

"You might have noticed a vapour coming out of the exhaust of some cars in the early morning. That vapour is not the oil vapour of a worn engine, but the normal water vapour from a cold engine. So the longer you idle the engine, the longer it will take to warm up, and so more water droplets will be deposited inside your exhaust system – making it rust sooner."

The vapour is not from the engine!!!! Its the condensation in headers & exhaust!!! (just like on your windows in the morning). Hence why vapour doest come out straight away, since it takes time for exhaust to warm up & begin evaporating deposited water.

"Idling also drops the temperature of the spark plugs, leading to dirty plugs, which can worsen your fuel consumption by some five per cent."

Yea probably, but 5 percent claim is outrageous, so what i warm up my car everyday now my consumption will be 5% worse then someone who doesnt? What a load of crap, yes dirty spark plugs might cause bad consumption but ive been warming up my car for over a decade & never had to change a plug prematurely, whats more i never noticed any difference in fuel or idling when new plugs were put in during service.

Again im not advocating for warming up the engines, just saying that this person who claims its bad for your car, really got few fundamentals wrong.

No,
The vapour is not the exhaust, it is from the result of heating up air during combustion and the water comes out of the air, this also mixes with oil and degrades the oil. A classic example is some of the cars I have here, in winter if I do not give them a long run each week (as opposed to just starting them, back them out and shut them down) the oil goes milky as if there was a blown head gasket.

Of course your fuel consumption will increase if you warm up your car, just like when stuck in traffic as most measure consumption compared to milage done, if oyu are stationary you are not doing any mileage thus when you do your calculations you will have traveled less distance for more fuel

Its obvious that warming will decrease your fuel consumption, my comment was in regards to spark plugs. I used to drive 600ks a week for over 8 years, idling for 3 minutes everyday is negligible as you spend a lot more time idling at traffic lights. I never noticed any difference in idle or consumption once new spark plugs were put in, which brings me back to my point that idling does not damage plugs enough to show any fuel consumption difference.

Yes car will produce steam on start up until exhaust system warms up. Hydrocarbon (fuel that we burn), hydro component is hydrogen obviously, once burned will produce water, this water will condensate on cold exhaust piping, once exhaust start warming up this creates steam, once exhaust is hot enough condensation no longer occurs & vapor becomes invisible (bit it still there).

I still maintain that most of the steam you see is a result of overnight condensation in the exhaust itself.

Its obvious that warming will decrease your fuel consumption, my comment was in regards to spark plugs. I used to drive 600ks a week for over 8 years, idling for 3 minutes everyday is negligible as you spend a lot more time idling at traffic lights.

Yes car will produce steam on start up until exhaust system warms up. Hydrocarbon (fuel that we burn), hydro component is hydrogen obviously, once burned will produce water, this water will condensate on cold exhaust piping, once exhaust start warming up this creates steam, once exhaust is hot enough condensation no longer occurs & vapor becomes invisible (bit it still there).

I still maintain that most of the steam you see is a result of overnight condensation in the exhaust itself.

If you read the article posted above, it mentions about unburnt fuel from idling stripping the oil off the cylinder wall when cold, not sitting at a set of traffic lights. This wont happen if you drive the car from the get-go and allowing the engine to burn as much fuel on each cycle as possible

Yea but you end up with richer mixture (when engine under load) hence even more fuel to wash off the oil, until engine warms up, how is this different to smaller washing effect for a longer period (when idling)?

Yea but you end up with richer mixture (when engine under load) hence even more fuel to wash off the oil, until engine warms up, how is this different to smaller washing effect for a longer period (when idling)?

You are purely speculating this with no hard evidence, whereas the article explains it all well. There is a reason that manufacturers tell you to not leave a cold car idling.

It wont get any richer mate. Dare i say that a stone-cold idling engine will be dumping fuel in at very high amounts

So your hard evidence is an article?

What your telling me is that amount of fuel in the cylinder is the same on idle vs the engine under load (richer is the wrong term, lets talk about amount of fuel)? Simple physics will tell you that more energy is required to move the car, hence you will use more fuel in the same amount of time, if im wrong then please attempt to drive your car without touching accelerator with engine idling. So unless you refer to crawling on idle speed as driving...

I dont believe warming up is required, but to suggest that it will damage your engine is just absurd.

its the same thing i do wait for car to warm up before driving off, i never drive my car cold i just hope im doing the right thing.

its the same thing i do wait for car to warm up before driving off, i never drive my car cold i just hope im doing the right thing.

Read the thread. Every technical article I have read on the web states it is BAD to leave an engine idling for a long time from cold. Get in, drive it. Simple as that.

I dont believe warming up is required, but to suggest that it will damage your engine is just absurd.

Why is it hard for you to believe it? There is conclusive evidence that leaving a car idle from cold increases wear and tear on engine components.

You say that you have always done this and have never had a problem, but your aged engines might not be performing as well as if you had not spent hours and hours over the course of time idling the thing from cold.

Oh FFS you are all right in different ways

Yes a cold idle is very rich, this is to keep the motor running smoothly,stop it stalling when the load starts and will wash the oil off the walls of the cyl

Yes, SOME of the steam is from the exhaust however MOST is from combusion

NOW lets move on back to topic please, all this back and forward BS is why so many people dont bother with AMC anymore, to get a simple answer to a simple question people have to troll through 20 pages of arguements and bullshit often not even related to the initial question

NO MORE OF THIS PLEASE, if you are not answsering the question of the OP which has been answered many times over, move on

hi
it's funny cause i'm more confuse than before!! b ut learn a lot as well.
anyway i had try this morning and drove out without warming it up and the drive was pretty crap,,it felt like it had no balls

hi
it's funny cause i'm more confuse than before!! b ut learn a lot as well.
anyway i had try this morning and drove out without warming it up and the drive was pretty crap,,it felt like it had no balls

Thats normal until its up to temp. Mine is awful when cold

my JDM Diamante limiter is 6200rpm when cold, and 8200rpm when warm. it also wont engage mivec when cold. i do like to start the car and let the idle rise and settle for about a minute. my old carby Isuzu trooper (holden jackaroo) was bad, would idle like a bridge ported rotary till it was warm .... waaaap waap waap. lol

uuhh
well i will start driving it cold!!
all the best