Toyota estima, idling problems

dellboy2, Jul 27, 2:17am
Good afternoon gentlefolk.My daughter's 1992 petrol estima suddenly has developed a really rough idle/almost stalling."Seems"worse when warm.I did a bit of googling, and "idle control valve" came up a quite bit, but more for overreving at idle.This car has been pretty good so far, so hav'nt had to look at much.I Just nipped out of work to have a look, but anybody who's had or worked on these, knows things are in weird places.Where the bloody hell is the idle control valve!Or any other suggestions (serious please) welcome.Thanks in advance, for looking/help.

mm12345, Jul 27, 2:23am
I think from my experience with toymota IACVs, while I guess they could result in over revving at idle, normally they get sticky/gummed up close to the closed position, and the result is slow idle, stalling when idling when the car is sitting in "D".

They're normally in the throttle body, as they specifically allow air to be metered past the throttle butterfly.When stuck, the sometimes respond to a spray of carb cleaner down the throttle body and in to the IACV intake, but other times you're gong to have to remove the throttle body to pull the IACV out to clean it thoroughly.

gammelvind, Jul 27, 8:03am
Remove the throttle body, fiddly but you should be able to do it all in a couple of hours. Clean it with a good carby cleaner, remove and clean the idle control valve from the throttle body and reassemble. Put plasters on your knuckles and all is good.
Well thats how it worked for me

dellboy2, Jul 27, 10:32am
Okidoki; well thats my first job tommorow then, after its warmned up a bit out there.Thankyou for your help.Yeah that throttle body could be a bit of a bummer to get off. But hey isnt that what the japs are really good at.must be those tiny fingers!(no insult implied)

the-lada-dude, Jul 27, 8:27pm
i dont think you have to take the thottle body off, might just be 4 x screws holding the plunger bodya i s cto the T / B

kazbanz, Jul 28, 4:20am
i aggree to clean out the throttle body but the afm might be another option

dellboy2, Jul 30, 8:13am
Ok thanks guys for all your advice.Saturday found the aisc after some considerable shagging around got the sucker of the throttle body.Cleaned it all up, sort of suzzed how it works.(at this point, if anyone can tell me what "normal" position should the gap in the valve be, like in its, no turning of the end of the shaft while I had got it off, and in my hand) anyway , put it back on.Even worse, left to idle on its own, engine would stall.Tried a "reset" by disconnecting batttery for 10 mins, still crap, seems ok until driven it just a bit.Just to give me some breathing space, have a fiddle with a screw/allen key/lock nut on what appears to be a throttle stop/idle.Anyway that sort of fixed it for a day or so.Yes I can remember where it was set up!. So I guess its time to remove complete throttle body and clean.Apparantly today it was really bad, and even the electric frypan (is it the catalytic convertor) light came on.So still looking for help.cheers

mm12345, Jul 30, 8:29am
CC light is probably indicative of too rich mixture.Assume that the IACV is okay for now, as the O2 sensor should pick it up and reduce fuel and open the IACV to maintain idle speed. But probably not enough unburned HCs at idle to start overheating the cat if the IACV was the problem.
As Kazbanz suggests, it might be the AFM, but also the O2 sensor, and also spark plugs/cables etc, especially if there's any sign of missing at higher/normal revs. My guess is O2 sensor.I'm sure someone will disagree.

gammelvind, Jul 30, 8:46am
When I took mine off, I removed the complete body. I'm glad I did, was it gunged up, plus the butterfly would stick in the closed position just because of the gunge, this would also affect the idleing.I scrubbed and squirted carb cleaner down all those tiny holes. In the end nice a clean throttle bodyand the butterfly needed just a light touch to move it. Would still be full of sticky gunge if I had only removed the AISC.
There was no need to adjust anything when reassembled as now all was working properly. Hasn't missed a beat since.

dellboy2, Jul 30, 9:26am
Okidoki, a bit of a update; now your gonna think i'm mad. But I try this about 45mins ago.Managed to get the air pipe off the throttle body , squirted a whole loader carb cleaner in, with aid of someone cranking starter, pipe back on.Umm runs like a bag off shit, seemed to settle down, took it for drive, ok for about .5k then, well now its really rough.Poor idle, running really bad, and the electric frypan light was on (red).I don't think I've introduced a problem.I think its just got worse.May have to leave now till w/e and check/test spark plugs and leads.I have not heard of electronic problems with the ECU's for these, I am aware of MItsi ECU's at ths age giving problems.And have fixed a few over the years (electronic tech. by trade.not choice!) I did try to remove ECU so could take covers of in the dry and warm, but just as a cruel twist of fate, the last nut on this poxy bracket is so tight the whole bracket is twisting.Ah F$%K it I thought.Time to catch up with my new mates on TM.And maybe a rum to ease the pain.

dellboy2, Jul 31, 2:20am
Ok what a wasted day so far. Iv'e had the throttle body off, and cleaned it up nicely.I also have front seats out, covers off. and had a check of spark plug leads, and distriubtor.All good (leads all measure a simaler resistance).Plugs were a bit too gapy, so bought some new ones.Bloody hell $128 later.Just tried it.exactly the same.So tell me about oxygen sensors then!

gadgit3, Jul 31, 3:07am
Are you sure the spark plug leads are ok! a resistance test wont tell you if the lead has a fault in the cermic part of the lead. It is a common fault (pin holes in the lead) and will cause the converter light to come on when the engine is pushed as there is a huge amount of over fueling going on in side the converter.

gadgit3, Jul 31, 3:09am
Heres what to do just as a check. Remove the leads and with black eletrical tape layer the ceramic part of the lead from top to bottom on all 4 leads then run up and see if there is a difference.

dellboy2, Jul 31, 10:27am
Hey around the time you were replying to my almighty quest.I was still shagging about with this car, and a just a bit dispondant(to say the least!)Just as a "what if I try this" pulled each plug lead off, and started, ran motor up.Just to see if there was a difference.Last plug lead nearest distributor.Had the plug lead resting on the metal floor.and sparks everywhere.Bingo, just as you say the long hard "plastic" bit was etched with carbon burns.Unfoutunatly no matter what I try, cant contain that spark!So up for some new leads tommorow.Christ there expensive too!Best price $205.worst $256.Only need one though.However, thankyou all for your ideas and thoughts.Some learning curve this has been.But at my age, I'll have forgotton it in a few days!Wer'nt old cars easy to fix! Eh, mind you on a more regular basis.I wouldn't go anywhere without enough tools and bits, to get most cars going again at the side of the road.How times have changed.Thanks again.

thunderbolt, Jul 31, 10:35am
Replace all of the leads, the others wont be far behind the one that has already failed.

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