High cold idle-shifting into drive question. (1 Viewer)

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Jan 7, 2009
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When the engine is cold it idles around 1800 RPMs for a few minutes then steadily drops to normal idle. I almost always wait for the idle to come down.

Sometimes I am in a hurry though.

Is it hard on the transmission to shift into gear with the idle high? Does it do any damage?
 
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man mine does it too- i have tried o-ring in the iac with no avail- i wish someone knew exactly what caused it and what would fix it-
 
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I thought it was supposed to idle high at startup.

I guess fixing the high idle would be preferrable if it isn't designed to do that.

I was just wondering if it was hard on the transmission to shift into gear when the idle is that high.
 
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a friend of mine has a similar problem. He has a 94 and until the engine is warm his will not shift into overdrive.
 
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Does anyone think shifting into gear while the RPMS are around 1800 does any damage to the transmission or cause more wear?
 
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Centerton, AR
I usually wait until the idle has come down a bit before shifting into gear. It gives the oils time to circulate and avoids having to worry about any possible damage.
 
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this was one of the things that drove me crazy about my truck when I first bought it........I think my cold start was closer to 2000 rpm and it made me cringe every time I fired it up. Had some timing chain slap also for about 3 seconds.

The o-ring mod worked for me, after some trial and error 2 o-rings stacked brought my cold idle down to 1200 and it has stayed that way since. (2 years)

The hardest part of the mod is cracking loose the little phillips screws on the IAC, I used a hacksaw to cut a groove in 2 of them in order to use a slotted screwdriver to finally break them loose.
 

80t0ylc

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One thing that might help for those dealing with high idle before warmed up is when approaching a stop sign or light, I'll shift to Neutral to save wear and tear on brake pads. This thing has so much low end torque that it seems like the brakes are going out till the engine idles down. - My .02
 

ToothDr

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All of these trucks will idle high until they are warmed up. The question seems to be how high of an idle. Mine idles at 1400RPM at cold start. The moment I shift into reverse the RPM's drop to 1000 or so. I have no issues about shifting into reverse or drive when the truck is at high idle.

When we bought our 1994 new, it idled at 1400 RPM from a cold start. 1600-2000RPM's is too high, the previous posters noted some ways to correct that
 
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Imperial Valley, CA
 
One thing that might help for those dealing with high idle before warmed up is when approaching a stop sign or light, I'll shift to Neutral to save wear and tear on brake pads. This thing has so much low end torque that it seems like the brakes are going out till the engine idles down. - My .02
Are you saying you are more concerned about wear and tear on a consumable part(brakes) than you are on the transmission? wut?
 
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Clean that throttle body

All of these trucks will idle high until they are warmed up. The question seems to be how high of an idle. Mine idles at 1400RPM at cold start. The moment I shift into reverse the RPM's drop to 1000 or so. I have no issues about shifting into reverse or drive when the truck is at high idle.

When we bought our 1994 new, it idled at 1400 RPM from a cold start. 1600-2000RPM's is too high, the previous posters noted some ways to correct that
x2......mine starts @1400rpm for a few seconds when cold, and I immediately slam it into reverse (then it drops to 1000rpm because of the trans load) everyday for years with no issues. Slushboxes handle this better than manual trannys, as they are "hydrostatic" to an extent. I agree that 1600+ is too high, and troubleshooting is in order. It is normal for the 80 series not to shift into OD until operating temp is reached.
 

Squash

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I am begining to feel that our issue lies with a coolant temp sensor...this is because when using the block heater because of winter weather she fires up and idles almost perfectly.
If not plugged in then higher rpms.

Cleaning the intake and vaccum hoses help as does removing the IAC, have even stretched the spring which seems to help...maybe a new spring? mind you this is not a dealer item but surely there is a similar spring out there somewhere.
 
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clean your pcv piping in the manifold and throttle body of carbon build up....seems to be the fix for the high idle start ups.
Have you all done this? If you already have then keep on searching but if not then go ahead and keep on wasting your time with o-ring mods and other bulls*** when the fix is right in front of you...but what do i know, im a noob :meh:
 
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Have you all done this? If you already have then keep on searching but if not then go ahead and keep on wasting your time with o-ring mods and other bull**** when the fix is right in front of you...but what do i know, im a noob :meh:
by PCV piping you mean IAC valve piping in the throttle body correct..............yeah did all that and it was the o-ring mod that brought the idle down to where I wanted it, but I guess it was a waste of my time like you said.
 

80t0ylc

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Are you saying you are more concerned about wear and tear on a consumable part(brakes) than you are on the transmission? wut?
Is English your second language?:D How is putting the tranny in neutral while stopping, going to put wear & tear on it? And only for a few stops, while the engine's idling fast, to try and help save brake shoes that wear out much too fast anyway!
 

80t0ylc

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I was thinking about the wear and tear when you drop it back into drive. Wouldn't that put wear on the clutch packs?
Good question! I'm no tranny expert, so if there are any that know, please chime in. Situation: Due to high speed idle from cold engine and concerns not to waste fuel and possibly running late, operator chooses to proceed instead of waiting for idle speed to return to normal. With the 1FZ engine's high "low end" torque, operator chooses to slip tranny into neutral as he approaches stops (signs or lights) to try and save wear and tear on brake shoes. Coasting maybe, 50 - 75 feet, and then slipping back into drive when ready to proceed. Doing this till engine idle returns to normal. Will this cause any problems in tranny? Or elsewhere?
 

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