Toyota Carina 1989 G Reg High Idle Speed Solution Required

[M.Iqbal]

hi

I have a Mark 2 G reg Carina 1.6 GL (carb) with 52000 miles on the clock. Over the past few weeks the warm engine idle speed has risen gradually and now it ticks over at 1500 rpm when the engine is hot. I have check the air intake and all seems fine. I have also tried to adjust the idle speed but this makes no difference at all.

I was wondering wether anyone can make a suggestion as to the possible solution to this problem and wether its an expense fix if done at the garage.

thanks in advance

miq

[gazza1286]

How have you tried to adjust the idle speed?

[M.Iqbal]

How have you tried to adjust the idle speed?

hi

i tried it by turning the white headed screw at the rear of the carb

regards

miq

[gazza1286]

Well that is the correct adjuster?????

You say that turning this had no effect on the idle speed? That can't be right!

Is it possible that the plastic cap is just turning on the shaft and the shaft isn't moving??

Is the choke flap fully open - you should be able to check this by removing the air-filter cover after the engine has warmed up. The flap in the centre should be fully open.

[M.Iqbal]

Well that is the correct adjuster?????

You say that turning this had no effect on the idle speed? That can't be right!

Is it possible that the plastic cap is just turning on the shaft and the shaft isn't moving??

Is the choke flap fully open - you should be able to check this by removing the air-filter cover after the engine has warmed up. The flap in the centre should be fully open.

hi gaz

thanks for the previous replies - i can confirm the adjuster is working because if i turn it the opposite way the revs go up but no matter how much i turn it in reverse the revs do not fall below 1500 - i dont want to turn it too much because it starts feeling loose. I have also looked at the flap and yes it is fully open so im afraid im still lost on this one. I have just put a bottle of carb cleaner in just clear things out but no difference.

regards

miq

[gazza1286]

The idle setting is meant to provide a fuel mixture to the engine with the throttle plate fully closed. If the adjuster cannot reduce the amount of fuel going to the engine I think that the throttle plate MUST be slightly open!

Three alternatives here:

(i) The throttle plate is sticking slightly open at the carb. Solution - WD40/oil the spindle and spring to get full movement. You will need to undo the throttle wire at the carb (see (iii) below)

(ii) The accellerator cable is jamming on itself or the return spring has come loose or is weak . Again check and lubricate

(iii) The throttle cable adjuster needs resetting. At rest there should be a reasonable amount of slack at the carb end of the cable. Enough so that the accellerator pedal has to move about 5-10mm before it begins to move the throttle lever at the carb. The adjuster is the two nuts on the carb where the outer sleeve is mounted.

My money is on the third option. Any adjustment will obviously mean that the idle mixture screw will need to be reset again.

Good luck