Idle raising and dropping.....SR-20

[Graphix1]

After driving for a while and then go into traffic the idle raises to about 1500 and the drops to about 500 over and over..it only happens when the engine is at operating temp for a good while...

the only way i get it to stop sometimes is to rev and release aggressively...

i checked and changed vacuum hoses,i took apart the iacv valve and cleaned it,the piston inside is moving freely i also cleaned the tb....

I can't think of anything else...

[QG]

Ahhh that sounds like a Mass Air Flow sensor problem.

Use CRC MAF sensor spray on the MAF just to give it a lil cleaning!

If it doesn't solve check into your spark plug wires, listen to hear if your car is mis-firing.

[Back2Studio]

500rpm is too low for standard idle of an SR. All you have to do is take a screwdriver and adjust the idle screw till the rpm reads about 750 or 800...also there might be oil on your #1 spark plug.

[Graphix1]

cleaned air flow,no oil on plugs...

Normally it idles at 750 at op. temp. it only fluctuates after a drive say from town to nestle...then stop by a light...or go into traffic.

[X_Factor]

do u notice if the fan comes on or off while the temp drops?

[Graphix1]

nah....fans click on when really hot,never saw it come on below op. temp.

[ddog]

U try adjusting the TPR. U cud get some guides on the net for that. I think u sup to get 4.5v across two of the sensor wires on WOT.

We had the exact prob years ago with a SR. Adjusting the TPR helped a little (it was off on our engine) but the source of our problem was a bit retarded. We converted to non electronic tranny and forget to disconnect the original tranny brain. So the ecu was getting some messed up signals i guess....

[*$kїđž!™]

so ecu may be the problem then?

anyone know how to reset the ecu?

[Graphix1]

took out the plugs,discovered oil on all of the threads,washed them out with gas but the problem still persisted

[*$kїđž!™]

.....Graphix--does the car ever wanna cut off also?

[Graphix1]

yea.....when its fluctuating it drops low enough to almost stall..

it does this every time i drive but it only cut off once in d past 3 mths it doin this...

[*$kїđž!™]

well my car doing the same ---RPM dropping to cut off and then bam shoots up before car cuts off....It does cut off at least once for the day when the engine is heated........check lights blinks also

[krack korn]

known as "hunting"

research it on sr20forum

nigson a scan may help u

graphix it may help you too, but assuming you dont have a temperature sensor problem you need to do the set tps, timing, idle speed, routine

which sr20 u have high port or low port?

[nismaniac]

guys had this problem before...vacuum leak around the mass air flow just remove a nd clean maf with electrical cleanaer and put a thin film of silicone(not on the silver part just to make sure that there is no leak) and replace. It can also be that the maf connector is not grounded properly just make sure it is connected to the maf properly(when you get symptom just come out of your car and shake the maf connector and see if problem goes away).

If you from south and you want me to check it no problem..492 3628.. Dale
Let me know if you get through..definitely vaccum leak somewhere and an easy fix dont stress.

[nismaniac]

yeah and dont interfere with your idle just yet it wouldnt help

[Graphix1]

my first thought was exactly that.....bout 2 mth ago i realised the vacuum hose on d intake was collapsing with heat so i changed but prob still reoccured ill try re grounding d maf and putting a silicone gasket on it

[*$kїđž!™]

i need a mech to help me out here...can you guys recommend any.......

[dbaby]

I could help you check your pm