93 22re PU Apply Brakes Engine idle drops/stumbles through range...

[JJVonHemi]

Gentlemen, 93 22re pickup idle drops to rough also stumbles through rev. range/new plugs/ TPS/ No pedal fade on Brake Booster, could defective power brake unit have a vacuum leak without pedal fade? can't seem to locate any vac. leaks around intake/throttle body...WHAT AM I MISSING? PLEASE HELP , THIS IS MY BEST FRIENDS ONLY TRANS TO WORK,40mi. one way! Family guy he needs my/our help desperatly...Thank you so much for any assistance/tech advice you may offer...Peace.

[subliminaltrips]

hey man i have the same issue i have a rough idle so i adjust the timing and the screw on the throttle body out till it smooths out but when the engine is smooth it runs great until i apply the brakes. if i run the ac i notice if i turn the screw on that has 2 vaccum lines running to the intake it will idle higher and lower but the brakes do the same thing untill i turn the idle down to where its running rough its like a fine line too low idle runs rough too high the brakes bog the truck and it goes vrooom bahhh vroom bahhh. i saw another post about this but forget what the problem ended up being i think i might check the tps or something. also when accelerating i hear a suction sound kinda which does sound like a vacuum leak but i have tried starting fluid arround where it would leak and it doesnt race up.????? wtf

[JJVonHemi]

Man I really appreciate you takin the time ! Your situation sounds like a carbon copy of the time I'm havin! like I said the trk belongs to a great friend and I'd really like to whup this one for him!!! I've already replaced TPS @ $80.00 and I'm not one to piece by guess piece it back to operating status!!! Have also performed vac leak chk around throttlebody/intake area...could diaphragm in brake booster unit be at fault...? I'm not one to usually have these type of situations, I try to do my homework, Know what I mean...wtf! Do I need to learn to speak japanese? Thanx again look forward to hearin' from you in the future...I'm here if ya need me...JJVonHemi........

[fj40Dave]

It sounds like your vacume to the brake booster is leaking. Take a pair of vice grips and clamp off the line to the booster - that will trouble shoot it for ya.

Before ya go and replace the booster, make sure the line is not leaking.....cheaper than the booster and a lot easier

[subliminaltrips]

yea man ive been told its one of 3 sensors , tps, o2 , and map sensor. i dont know but i think im gonna call a mechanic and ask him. as soon as i figure it out i will let you know brother. and if you figure it out first let me know man, i really appreciate it , i know a few guys who are toyota guru's or so they claim so maby they will help . oh yea where the hell did you get a tps for 80 bux ours here run 108 bux and the 4 wire o2 sensor is 138 bux. so where ever you went up in ga is alot cheaper than the head busters down here in slow cala.

btw the booster isnt effecting mine because i did try this and nothing changed and if i push the brake pedal in it bogs but as soon as i push the switch for the brake lights back in or even remove the brake fuse it goes right back to idle steady. but the thing that is bothering me is why is the engine idling rough at the rpm its supposed to (750 to 800) so if i crank the air screw out to where it picks up speed it smooths out a bit and doesnt shake as radically but once its warmed up it starts to do it. it does not doo it durning fast idle at cold start up and it only does it after i drive the vehicle a bit but if i hit the gas pedal and quickly hit the brakes it goes down to a lower rpm than it does if i hit the gas and just let off . ?? ?? ?? so im stumped and im determined to get this thing to purr like a kitten. as far as power its one of the best 4 bangers ive driven then only engine ive worked on or driven from that year was a nissan ka24e and for a 12v valve engine with the same displacement the yota engine with only 8 valves is very close to the nissan. but anyways im fittin to whoop this yota. if you could decribe your symptoms and troubleshooting it would be a great help to me also. hope this helps you.

[rentz]

I have a 94 truck that is doing this exact same thing, its been driving me nuts for months, having tried everything to narrow down the problem. I'm glad I am not the only one going through this.

[subliminaltrips]

Originally Posted by rentz

I have a 94 truck that is doing this exact same thing, its been driving me nuts for months, having tried everything to narrow down the problem. I'm glad I am not the only one going through this.

what its everything just wondering if maby i forgot something? was it the o2 sensor tps or map sensor?

[body]

Maybe, just maybe the EGR syst needs some attention, could be dirty or clogged and not closing fully..Just something more to ck.

[JJVonHemi]

Well gentlemen I'm still on this one...heres some mo info chek this s--t out! This truck like will fire & run till warmup then turns ill idle/stumbles when applying brakes...I removed fuse for brake lights and no longer stumbles or rough idle now I high idle around 850-900rpm and an effin' wiring situation...I now need to find a wiring diagram... Yall are just way too much...I cannot thank you guys enough I do hope the lil bit of info I relay might be of assistance to someone....hey sublimimal...go pull the brakelight fuse!!! hell man I'm really not an import kinda fella, I gotta feel that detroit iron thumpin eights!!! Peace...PRAY TO KEEP OUR BOYS & GIRLS SAFE AND BRING THEM ON HOME ASAP...PS.PRAY FOR IRAQ TO HURRY THE HELL UP AN GET THEIR SHIT TOGETHER!!! TERRORISTS PRAY ON FEAR & WEAKNESS....WELL I HOPE I CAN SPEAK FOR EVERYONE WHEN I SAY"WE'RE NOT WEAK AND SURE AS HELL NOT SCARED"!!! JJHEMI, THE SON & GRANDSON OF VETERANS.

[lbyt]

i need some major help have 94 similar problem mine idles high after warm real high, when i step on the brakes it bounces between normal idle and 1800 rpms, occasionally i can bang on the thermostat and it will run fine, i know its not the thermo cause ive tried 4 different thermos also my heater wont work well when it is doing this, any suggestions would help i was thinking it was my temp sending unit oh yah i have adjusted my idle and checked all vacum connections none of the mechanics around here know what to do either

[subliminaltrips]

well i managed to get the truck to stop bouncing idle when braking by adjsting the hell out of the timing and the air adjustor screws. i got the best results by turning the air screw on the throttle body to the right as far as is would go and then i adjusted the timing to a slight retard . i then played arround with the throttle a lil to see where the best idle was and adjusted the idle speed screw and the fast idle screw accordingly. yea i know its kinda brief but it did stop the bouncing idle but it still idles a lil rough , engine shakes a lil more than normal at idle. i think im going to clean the egr valve and try that if that doesnt fix it i think the o2 sensor will be next. im still debating on taking it to a mechanic and let him tell me what he thinks it is and then buying the part myself. im also thinking that the temp sender might be a problem too because when its cold it runs smooth and the idle alot smoother than when its warm. i thnk im just gonna be the guinnea pig and get it fixed.

i also notice when i reve the engine and just let off the gas it comes down to a higher rpm than if i rev and hit the brakes . when i rev and hit the brakes it goes to a lower rougher idle than when i just let off thye gas, even in neutral at a stop. but if you remove the brake fuse is has no effect. so its not vacuum its obviously electronicly controlled. why does it do this? is it the ecu hooked to the brakes so it knows when you hit the brakes ? boggles my mind.

[subliminaltrips]

Originally Posted by subliminaltrips

well i managed to get the truck to stop bouncing idle when braking by adjsting the hell out of the timing and the air adjustor screws. i got the best results by turning the air screw on the throttle body to the right as far as is would go and then i adjusted the timing to a slight retard . i then played arround with the throttle a lil to see where the best idle was and adjusted the idle speed screw and the fast idle screw accordingly. yea i know its kinda brief but it did stop the bouncing idle but it still idles a lil rough , engine shakes a lil more than normal at idle. i think im going to clean the egr valve and try that if that doesnt fix it i think the o2 sensor will be next. im still debating on taking it to a mechanic and let him tell me what he thinks it is and then buying the part myself. im also thinking that the temp sender might be a problem too because when its cold it runs smooth and the idle alot smoother than when its warm. i thnk im just gonna be the guinnea pig and get it fixed.

i also notice when i reve the engine and just let off the gas it comes down to a higher rpm than if i rev and hit the brakes . when i rev and hit the brakes it goes to a lower rougher idle than when i just let off thye gas, even in neutral at a stop. but if you remove the brake fuse is has no effect. so its not vacuum its obviously electronicly controlled. why does it do this? is it the ecu hooked to the brakes so it knows when you hit the brakes ? boggles my mind.

well today i found one thing that definatly contributed to the truck idling high... the air adjustor screw on the throttle body vibrated loose to where the idle was higher than it should be.. as soon as the idle is above a certain point (roughly 1200 ) rpm the truck stumbles under braking but at a stop light i had the thought and quickly jumped out and twisted the screw back really fast before the light changed and headed up i 75 to my exit by the time i got there it was loosened up again... so i got home pulled the screw out and put some teflon tape on the thredz. problem fixed.

that screw turns very easily and will vibrate loose if your experiencing a faster idle than normal this is something i would check.

[VULLER]

Hi Guy I Have The Same Truck 2wd Stick, What You Need To Do Is This , Under The Hood Over The Right Fender , There Is A Little Gray Box It Says Diagnostic On It , Open The Box And Under The Lid There Is A Diagram You Ned To Get A Little Wire Stick One End Of It In The Ie Slot And The Other End In The "e" Slot Then Go Into The Car Turn On The Ignition But Dont Start The Car Look Under Your Speeometer And You See Engin Flashing This Is The Code You Need To Count The Flashes And Record Them On Paper You See Short Flashes With Pause In Between Each Pause Idicates A Dash Between Fast Falshes Which Indicates A Number After Looking At This You Will Notice The Pattern Will Reapit Itself. Once You Get The Nubers And The Pauses In Between Recorded You Need To Look This Code Up In Hains Manual Which Tells You What The Problem Corsponding To The Code Is. This The Cheap Way Of Doing It, Also You Should Replace The Plugs ,distributer Cap And The Rotor. Bad Distributer Causes The Similar Low Idel. Good Luck

[subliminaltrips]

Originally Posted by VULLER

Hi Guy I Have The Same Truck 2wd Stick, What You Need To Do Is This , Under The Hood Over The Right Fender , There Is A Little Gray Box It Says Diagnostic On It , Open The Box And Under The Lid There Is A Diagram You Ned To Get A Little Wire Stick One End Of It In The Ie Slot And The Other End In The "e" Slot Then Go Into The Car Turn On The Ignition But Dont Start The Car Look Under Your Speeometer And You See Engin Flashing This Is The Code You Need To Count The Flashes And Record Them On Paper You See Short Flashes With Pause In Between Each Pause Idicates A Dash Between Fast Falshes Which Indicates A Number After Looking At This You Will Notice The Pattern Will Reapit Itself. Once You Get The Nubers And The Pauses In Between Recorded You Need To Look This Code Up In Hains Manual Which Tells You What The Problem Corsponding To The Code Is. This The Cheap Way Of Doing It, Also You Should Replace The Plugs ,distributer Cap And The Rotor. Bad Distributer Causes The Similar Low Idel. Good Luck

hey man thanx for the info but i know how to get obd codes , the only code i get is a steady flash every half second. (no errors) as far as the distributor itself its brand new along with the ignitor /coil i bought from napa . the cap,rotor,plugs,wires, fuel filter,air filter and pcv valve are all new too. what i actually found wrong last week was a huge vacuum leak on the bottom side of my intake manifold. i replaced the gasket and it did help alot but its still running rough at stsrt up. i have tested and adjusted the tps sensor it checks out ok. the o2 sensor is working fine i belive the problem is somwhere in the emissions system ie a vacuum line or something. maby a vsv switch ive been tinkering a bit and hopefully i get it right soon enough cuz the way it runs now at operating temp is great i raced an 04 honda civic with the 1.7 v tech 5 speed and stayed right beside him till 70 mph and he jumped the light. if it would have hooked up it would have smoked him. thanks for the info though man.

[hiwaystar]

I was having similar problems with my 93--seemed like a vacuum leak someplace because idle would stumble when depressing brake. Also blew serious carbon. Went down same path of changing plugs, wires, cap, PCV, O2 sensor, but only helped slightly. Numbnuts at dealership told me it was a faulty air flow meter. Instead of their $550 model, I opted for junkyard version for $90 bucks. This still didn't solve problem. I knew I was getting air flow or exhaust pressure problems, based on Haynes research and this website. Computer gave me a 31, which was either air flow meter or manifold pressure sensor. Through trial and error, finally determined problem to be bad catalytic converter. Changed cat and muffler and problem is now solved. Moral of the story. Never trust the dealership. I would have saved over $400 bucks and would still have my original air flow meter.