another bloody idle post (but with a new idea!)

[thanuttiscotsman]

hi folks,
i know we have yaked about this for hours but i got a thought the other day i think may work!! now was looking at my spare tb yesterday, which is actually the cars origional. i have already set this thing via tps so the flaps are as closed as possible so to gain the lowest idle speed. now looking in at the ports the flaps dont seem to be at a 90 degree angle to the ports so im thinking maybe they are slightly open and causing the high idle. now on investigation of other possible adjustments i noticed the stop screw obviously set when new to suit the car then and tamper proof capped. i thought what if that doesnt suit the car now because the cars worn out in 16 years. well i went about trying to adjust it to see if the flaps could be closed more but couldnt get the tamper proof out and couldn't turn it with pliers. well as i have a spare tb im thinking of grinding a tiny bit at a time off the stop screw to see if the flaps are then allowed to close more which if they did would defo lower the idle. what do you guys think about my radical idea??? could it work. will be worth me trying as i have a spare and one spot weld followed be alot of sanding or light grinding could always take it back to where it was if the idea fails.

tell me what you think and has anyone tried this before???

cheers rossco

[ollie]

not likely to be the cause of acrappy idle as the AFM measures all the air going in regardless of whether it passes the stepper motor or the Main throttle plates.
The prob with worn TB is not setting the idle switch, tha actual air leakage is irrelevant, as more leak here just means less Stepper action, and too much air = fast idle and thats usually better anyway!! sorry.

Now if it was a Fiesta with a shitty Non adjusteable throttle POT then it would help but not much.....

[Mike E (uk)]

I investigated this last weekend.

A worn AFM could well be the cause of a crappy idle.

The AFM measures the air flow by the simple device of a potentiometer with the wiper fixed to the flap. When the engine runs, the wiper moves up and down on the carbon track, and the voltage from the wiper fed back to the ECU to set the amount of fuel injected.

On my car, the carbon track was worn, which made the idle hunt and misfire, and gave a very smelly exhaust. It also run lumpily at low throttle settings.

You can test for this by removing the AFM lid gently pressing down on the wiped while the engine idles, and see if this smoothes the idle.

I have not put a CO meter on the exhaust yet, but the idle is now very smooth and not smelly since I moved the position of the wiper so it runs on an unworn piece of track.

I found some notes on the web, which suggested I pressed on the wiper near the pivot so the contact was closer to the inner part of the track. I cleaned the track 1st with IPA. Gently does it. Then I adjusted the idle screw for a smooth idle.

It feels like a new engine now.

I will check with CO meter ASAP.

Mike

[MoRtYMer]

Does someone have some good photos of the process of "retracking"?

Luke posted a file with some, but they where tiny so it was difficult to understand what to do...

Cheers,
João Proença

PS: whats IPA?

[thanuttiscotsman]

hi there,
my idle is as smooth as a baby bum!! and very steady, the problem is it sits at 1300rpm all the time. its a bit smelly but not bad. car is generally happy but idleing at 1300 rpm means on idle it starts to overheat so i have to turn it off for a while and also means it burns a shi*load of fuel just ticking over. i mean about a gallon per hour which is rediculous by any standards. my old 1.4 rip would idle for about 4 hours even with a little choke on 1 gallon so i know its a problem. i just cant figure out how to get the idle down. i have a replacement tb on and a re-conditioned afm that cost me 205 quid. and ive still got the problem. one good thing is when you drive her around a bit the water temp goes down to about 75 or 80 and stays there happily.

i know the icv works as every time i start the car it first revs up the 3000rpm then goes half way back down then revs up again itself to 2000rpm then goes back down a bit then same again before it settles on the 1300rpm idle. it does this every time i start it. it almost sounds like its struggling to get a reading from the afm on start up thats why it revs it everywhere till it gets a reading. i have taken the lid off the afm re-tracked it and adjusted the spring tension. now it burns alot less fuel there is no smoke any time from the exhaust and idles smoothly but at high speed.

i have tried all the previous spraying wd40 around everywhere to see if it revs up and all that malarky but there still appears to be no airleak. now something, i am an idiot i forgot to mention, sometimes when she is warmed up and runningaway at 1300 rpm idle sometimes she just switches down to 1000 rpm and idles so quiet it sounds like someone whispering but that only happens for max i think one minute then she runs away again. maybe its my ecu or a sensor not connected wire wise at the ecu end.

this is one of very few niggly faults i have left with the car as i have solved the rest. but it has done this since i got it. but only started it very very occasional switch to normal idle for max 1 minute since i have changed about 1 million parts.

bamboozled and pizzed off wit it, cheers rossco

ps peeps keep thinking im sure someone will come up with a radical idea that will help solve it,

cheers again rossco

[Jezziebx16v]

PS: whats IPA?

International Pale Ale i thought


Jez

[tim leech]

International pissheads association?

[djoptix]

Rossco, I would do a thorough clean of all the electrical contacts you can find, if you haven't already...

[Mike E (uk)]

India Pale Ale is what you want.

[thanuttiscotsman]

hi there,
i have tried cleaning alot of the contacts but with no joy. i think i will try grinding down the stop screw a little. its worth a shot as i cant see it doing any harm and i dont need the car for the next year. if it is any electrical part it is probally the bloody 200quid replacement afm. well i have another year to figure it out at least. but anymore input and ideas are welcome as i will try anything.

cheers rossco

[Toddman]

Indeef IPA is India Pale Ale such as "Flowers IPA" which is a fine pint.

IPA is also Isopropyl Alcohol - just a solvent suitable for cleaning electrical contacts that evaporates.

Retracking is ver simple you just cretae a new path for the wiper to tavel along.

Cheers
Luke

[thanuttiscotsman]

[quote="Toddman"
Retracking is ver simple you just cretae a new path for the wiper to tavel along.
Cheers
Luke[/quote]

hi there,
i thought from what i seen it moves along the same track but just starts at a different point??

rossco

[martyn]

Indeef IPA is India Pale Ale such as "Flowers IPA" which is a fine pint.

IPA is also Isopropyl Alcohol - just a solvent suitable for cleaning electrical contacts that evaporates.

Retracking is ver simple you just cretae a new path for the wiper to tavel along.

Cheers
Luke

Rossco, IPA solvent, or possibly Vodka, & retracking (not recalibrating) is a far better start than attacking a fairly delicate track with abrasives.

Martyn

[daaristieweer,wiedurft]

I said it before, on alfa 155/164 2 liters they used the same AFM, with nr
Bosch 0-280-202-202.
Good luck, i've changed everything, but have the same problems.
I'm using a ignition coil of an XM, but that's a;so not the problem, maybe a leak in the headgasket between cilinders?
Greetings,
C4HDI110
BXGTI16V '88

[jayw]

I said it before, on alfa 155/164 2 liters they used the same AFM, with nr
Bosch 0-280-202-202.
Good luck, i've changed everything, but have the same problems.
I'm using a ignition coil of an XM, but that's a;so not the problem, maybe a leak in the headgasket between cilinders?
Greetings,
C4HDI110
BXGTI16V '88

get a compression guage on it to check before you do anything else. at least its free to do!