acis problem!!!

[lodgeman]

hi can anyone post a pic as the the routing of the vacumn pipes for the acis. i am presuming that when the revs reach 4-5000 then the actuator opens and the acis butterfly goes flat- ie in line with the outer casing. reason for asking is that my acis seems not to be working. have vacumn going to each of the vsv's , vacumn coming from the tank. but no vacumn going to the acis at any rev. if i bypass the switches then it opens . i have replaced the vsv's from the spare ones i had and it is exactly the same! am i doing something wrong? if i remember correctly it was working ok when i had the other engine but it seems not to be working on this engine. can i run it fully open all the time?

[Paul Woods]

al,sounds odd... you need to confirm if the acis vsv is getting a switching signal,wire up a non flashing led onto the two wires on the acis vsv ,+ to + and - to - or it wont work....then route the led into the cabin and take the car out for a drive over 5000rpm....led should light up!

If it doesnt then the vsv isnt being switched by the ecu,maybe a broken wire... do this testicle and report back.

[lodgeman]

is it speedo driven then?or gear box signal? only i did the tps to speed sensor mod some time ago thinking that it was fixed and drove it down the motorway the other day and it still went funny after a while!

[Paul Woods]

its ecu switched,quite how im not sure but presumably the ecu sees X rpm with TPS and AFM signals and looks up a table to decide wether or not to open the acis vsv,thats usually how these things work.

[Paul Woods]

yep,spot on,if you bypass the vsv,effectively joining the tubes together that feed it you will be running with vacuum going straight to the actuator full time,this will keep the acis open under all conditions but may mean a loss of bottom end torque....what do you reckon tony?

[adamh]

it'l roar from low rpm's..... slightly! :)

[foxy-stoat]

Ps, to test for correct acis operation just start the engine and give it a blip on full throttle then release the throttle, the acis should move momentarily then go back to its correct position. :)

hmmmm

my one is stalling rather a lot, say after a drive 50mph+ and when you dip the clutch the thing stalls, release the clutch and bump starts again, dip the clutch and stalls again...etc etc

after stalling it trying to park, got pissed off and bump started it again, reved the nuts off it, then it ticked over fine.

ya reacon this stalling could be contected to a sticky vsv or acis or something like thay, maybe reving it up and moving stuff at higher revs clears the stalling fault?

[Paul Woods]

the stalling fault is directly related to how the ecu is controlling the ISC valve...nothing else,quite simply the ISC is being shut at certain times by the ecu for some reason and theres no air bypassing the throttle when there should be.

Im working on a solution i just need time.

Tony im not sure the acis will open at all when the cars stationery....im pretty sure the vsv only gets opened under load,i'll have to check.

[Paul Woods]

tony a thought crossed my mind,you know the ECT is part of the engine control ecu...what do you reckon powers that up? or integral to the mother board?....i was thinking if we simply power down the ECT inside the ecu (maybe one of the Black/orange wires is for ECT only????) ,thinking here if we turn it off it might give us a manual mode ecu with no need for extra inputs.

All theory and guesswork that one though,just thought id run it by you bud.

We could of course go for a purely mechanical solution,disable the ISC totally,provide the throttle body with a fixed air bypass with a grub screw for adjustability of the hot idle...then provide it some aux air bypass for cold starts and thats job done.

Tony and i are just looking for the easiest and best way forward to hit the problem.

[foxy-stoat]

BAH !! toyota's ecu's are far too over-protective !!! maybe way toyota's engines last farrrr longer than the normal rubbish i guess.

will wait for the fix then ! :)

[lodgeman]

foxy just adjust the throttle stop screw up to around 1200-1500 rpm , need a 8 mm spanner and a allen key. will get around the stalling when parking and gives only a slightly raised idle speed. higher revs for takeoffs as well :whistle: ;) ;)

[lodgeman]

i will be in polegate today with adamh if you want me to do it for you? will be there sometime after 12.30 .

[Paul Woods]

no dont do that al,it lifts the TPS off its idle contact position and makes the ecu use normal driving maps instead of idle control maps...we need the TPS to stay where it is.....i suppose you could then alter the TPS back off its IDL contact but this is a grey area.

[Fizzy]

Just a thought with the whole vsv/icis valve thing. I've noticed on mine that at part throttle it accelerates well, almost fully open pretty well, but when I put my foot to the floor there is a noticable power/acceleration increase compared to "almost on the floor" if you see what I mean.

Guess its to do with the "wide open throttle" mode? Seems almost to be reminescent (sp?) of the auto kick down mode...maybe doesn't kick open the acis valve unless you floor it?

...could just be a drawback of using a 5v signal on the speed sensor?

[foxy-stoat]

i didnt get a notification by email there !!! doh !!!

but i have fitted a 1000amp dry cell battery that i had in my living room running by camry driver's seat ( sad i know ) and since then it hasnt been mis-behaving.

dunno if the extra amps or having the battery disconnected for a while helped out??

but when the revs dropped low before, the lights dimmed a fair bit.

w

[Jiff Lemon]

Its a possible i suppose, but i dont have anything like enough info to say what the results would be.
Im kinda worried about removing feeds especially if we dont know exactly what theyre for.
Id suggest the wiring diagrams for manual and auto ecus need to be studied because ive not found anything to suggest that the wiring is majorly different.
thats my next port of call i think! :)

Just a random thought, but is it worth one of our american cousins finding us a manual ECU to ship over?