help... my car is sick on warm up

[gordon77]

hey ppl this morning i start my car and the revs shoot up to 2400 ok so im thinking there is a vacum line the poped off the throttle body (happened before) so i checked that and other vacum lines, everythings there. so i took off down the road and car was going sweet. hit traffic about 500m down the road. i slowed down and stoped and the revs were fluctuating (going up and down) around the 1400 mark (where it normally sits on cold idle) and then i saw something real weird. the temprature guage went from cold to normal temp in about 2 secs
traffic started moving slowley so i just chug along as u do in 1st and the car was jerking (probably due to revs going up and down) so i put up with it and in a few mins the revs droped down to 800 and sat there sweet, as if it had warmed up normally.
i came off the motorway and sat at the lights and the temp went a little higher that it should then went back down when i started moving. i know thats normal but it went a little bit higher this time....

i have also noticed that i have lost a bit of power in the low revs but that could be due to a bad tank of 98 fuel

friggen cars

[RickGT]

i had the same prob mine used 2 idle really high when its cold, dont noe y but i just turned down the idle screw haha

[gordon77]

anyone else?

[Jebus]

So is it fine once its warmed up?

i.e Idle doesnt fluctuate rapidly etc..

[mr pad]

Sounds just like my old smallport 4age. Could be TPS? Try replacing that.

Run some injector cleaner throught etc...

[gordon77]

So is it fine once its warmed up?

i.e Idle doesnt fluctuate rapidly etc..

yeah it idles sweet when its warm.

ill grap some cleaners and run them through and see what happens

[gordon77]

this is the temp that the revs start to fluctuate... when the temp goes up to normal the car behaves properly. anything under that it idles at like 2200

[levin_it_large]

sounds like it happens on all 4AGES...mines been like that for a while ... but temp hasnt changed to much.. i possibly need a new thermostat, within about 2 minutes its back idling at 800.. sound familiar?

[gordon77]

yeah sounds like it. my thermostat is only like 8 months old tho...

[Crucible]

hey ppl this morning i start my car and the revs shoot up to 2400 ok so im thinking there is a vacum line the poped off the throttle body (happened before) so i checked that and other vacum lines, everythings there. so i took off down the road and car was going sweet. hit traffic about 500m down the road. i slowed down and stoped and the revs were fluctuating (going up and down) around the 1400 mark (where it normally sits on cold idle) and then i saw something real weird. the temprature guage went from cold to normal temp in about 2 secs
traffic started moving slowley so i just chug along as u do in 1st and the car was jerking (probably due to revs going up and down) so i put up with it and in a few mins the revs droped down to 800 and sat there sweet, as if it had warmed up normally.
i came off the motorway and sat at the lights and the temp went a little higher that it should then went back down when i started moving. i know thats normal but it went a little bit higher this time....

i have also noticed that i have lost a bit of power in the low revs but that could be due to a bad tank of 98 fuel

friggen cars

This is a common problem with 4ages, Some hondas have the same setup. Your cooling system is either low on coolant, has an air lock in it or the cold start valve is faulty. The cold start system has a wax pellet type thermostat bulb that expands when hot coolant passes it. Located in the throttle body. When cold the valve is open allowing air to bypass the throttle butterfly and as it warms up it gradually closes the port allowing the revs to drop to normal. The valve wont see coolant if low as it is about the same level as the radiator top tank, this will cause it too stay open and the revs will indeed fluctuate. The gauge fluctuating is probably intermittent flow past the temp sender unit (Low Level). Power loss...well it needs coolant flow over the temp sensor so the e.c.u can judge inj/pulse width, and we all know what happens when motors get too hot

Just Check your coolant level and find the leak and or the above...

TNT

[Caveman]

Yep sounds like you have air locks.

As TNT said that would explain the large change in idle, air going through the cold idle up valve under the throttle body.

If you've dont a coolant flush make sure you use the heater on full for a while after filling the coolent again.

[gordon77]

sweet yeah toped it up yesterday. water level was just under the radiator core.

thanks tnt

[gordon77]

replaced the water pump and everything is sweet now. thanks for ur help