Toyota Idle Problems

[dbkimber]

i have a 1991 toyota pickup with a 22/RE an i have a problem with it i cant seam to figure out would appreciate any help

my problem is that when i step on the brake the engine starts to hunt (the idol will drop off to all most nothing then come back up then drop off again rapidly) the only way to stop it is to let off of the brake or to shift the truck into 4 wheel drive (with or with out the huns locked) any ideas of what is going on

 

[toyotafan]

When you step on the brake the engine will drop RPM and the idle will bog down? Is this in-gear or in-park?

 

[dbkimber]

yes the rpm drops and returns rapidly and continuously. i doesn't mater what gear im in just whenever im stepping on the brake at an idle unless i pull back on the 4 wheel drive shifter to put in to 4 wheel or i take my foot off the brake

 

[tbplus10]

Start looking for vacuum leaks, this is a classic symptom of a vacuum leak either in the brake booster or one of the vacuum lines.

 

[dbkimber]

is ther a vacume linked to the 4 wheel drive shifting because id i shift into 4wd it will stop

 

[GearHead]

is ther a vacume linked to the 4 wheel drive shifting because id i shift into 4wd it will stop

Anyone have an answer to this question? I agree that it sounds like a vacuum leak, but not sure why the 4WD would change anything with it. OP, did you figure out your problem? I'd like to know...

 

[dbkimber]

i cant figure it out its been in 4wd for the winter so havent bothered with it in some time but i have been chasing it since i got the truck in 2007 but have rean out of ideas on how to find it and where to look next

 

[1 bad tacoma]

try a tune up if that dont fix it try looking for the vacuum leak they are a bitch to find somethimes but thats what it sounds like

 

[tbplus10]

Vacuum leaks arent hard to find if you have an industrial size can of carb or injector cleaner, just start spraying the vacuum hoses if you've got a leak in one of them you'll know it right away.

 

[Techy855]

tbplus is right, not hard. Can be time consuming, but if you are thorough you will find the leak. I don't think the 4WD matters, could be a coincidence that it happens that way, or something about when you switch to 4WD shifts a hose around. Not likely cause it should do it either way, just a thought for why it would matter.

 

[TruckRider]

Hi dbkimber any updates on your toyota pickup issues? What causes the problem and how you solve it?