16 valve engine surging

[nutter]

Hi guys Ive got a 16 valve that was running fine on sunday now its surging it idles at 2000 then drops to 1500 then back any one come across this & how did you fix it

[Rotazuk]

Check it has water in it . I had a 4age that would do that when it was low on water . Temp guage always indicated normal . The ecu temp probe was in a different place and out of water .
never had it on a zuk motor .

Chris

[nutter]

I have checked that there is water in it & there is I have had one guy say check for air lock how do you do that ?

[graemec]

Do you have aircon?
I had similar symptoms when the aircon was binding a bit.

cheers

[nutter]

yes I have aircon ( its getting riped out) but its not that I removed the belt for a few seconds still did it

[dvszuk]

my 8 valve single point injection does that sometimes. and a mates toyota 3gse does that till it gets up to temp but dnt no what is making it do it.

[Steve_t647]

I had this once I suspect you have an idle speed solenoid that will pull up the idle when it thinks the engine is under load (ac comes on cold start etc) this could be on the way out.

I went to an aftermarket computer running a map sensor so never looked for the problem but prettu sure this will be the problem, disconecting it will stop the surging but can cause the car to stall doing anything from idle (drive off, ac comes on)

Good luck

[rolly]

Hi guys Ive got a 16 valve that was running fine on sunday now its surging it idles at 2000 then drops to 1500 then back any one come across this & how did you fix it

hi nutter i have this problem as well and i dont have ac but im runing a link computer.

[nutter]

Hi rolly I went through all sorts of things in the end I unpluged the choke plug & bingo runs well