I've been trying to solve this problem for weeks, I need some help.

Here is the symptom, the car drive fine after I just started the car, but after the engine warm up, when I stop in red light, the tachometer start fluctuating between 600rpm ~ 200rpm(the engine is shaking as well) a couple time, then it stop, after a few seconds, the tachometer fluctuate again.

When I accelerated, the tachometer doesn't go up smoothly, feel like the car is lack of power, especially doing even a small hill climb.

The RL is working fine, when the engine is still cold!

I changed the spark plug, air filter, cleaned up the EGR valve, pipe, and have no luck.

I'm not sure what to do next.

I appreciate any input.

 

Pcv

 

Thanks Ken,

I found a crack at the end of the PCV hose, can I just cut out the crack part, it's about 1 inch long, and reconnect the hose back or I have to buy a new one with the exact same length?

 

If there is enough hose length to cut off the split portion of hose you can do that and then just reconnect the hose. No need to replace it.

 

Thanks guys,

I replaced the PCV valve, it's way better now, the tachometer still fluctuate a bit, when I turn on the A/C.
Should I fine tune the idle speed?
Any thing else I should look at, thinking of get the throttle body clean.

 

Yep, throttle body is next. Gotta get all that gunk out.

 

Cleaned the throttle body, flushed the radiator and the idle is steady now, except that as soon as I turn on the A/C, the rpm drop couple hundred and fluctuate. After turn off the A/C, the idle is back to normal again. What should I check?

Thanks,

 

idle air control valve.


you can usually just unbolt and clean out with tb or carb cleaner. sometimes they get stuck with too muh gunk builds up inside them. usually makes the car idle go and and down repeatelty when cold too when theyre reall bad.

that is of course unless your compressor is a having its own issues of course. its frre to clean though if you can do it yourself and whont hurt nothing.

 

I cleaned the IACV, FITV, reset the idle speed.
When I do a cold start in the early morning the rpm will stay at around 500rpm, is it normal?
If I turn on the A/C the situation will get worse sometimes, the rpm fluctuate and drop to around 300rpm, the engine feel like almost going to stall.
What should I check?

Thanks,

 

not normal

How long have you owned this car and did you notice the problem getting steadily worse?


Do you use premium gas?

 

I have it in May. I use premium fuel. The RL is running fine when the engine is up to the working temperature with the A/C is on and Driving gear engage. When I turn off the A/C the RPM start fluctuate down a few times, then it is back to around 500rpm and stay.

I can warm up the engine before I drive, it's not an issue for me, as long as it won't lead to a major problem with a big bill after that.

Cheers,

 

Did a test on FITV again today. When the engine was cold, removed the FITV cap, started the engine. I could felt some suction. the RPM is up to 1300, that is pretty normal. As soon as I used my palm to blocked the hole as the cap did, the RPM drop rapidly.

I know the function of the FITV, but I'm not quite sure how it actually works. Anyone care to elaborate more?

Cheers,

 

i beleive it just goes up and down, making more or less air available as you open and close the throttle body. thats what keeps the idle under control. you can try taking both off and cleaning them real well, or they might just be bad

 

maybe theres air in your cooling system, and affecting the cold idle valve. That would be the cold idle issue but I wouldnt see the ac idle problem as thats controlled by the idle air control valve.

 

Thanks guys for the quick response.

I flushed and refilled the radiator last weekend follow exactly the steps from the service manual, except that, I loosen the air bleed bolt, but I didn't get any coolant run out from it. Maybe there is still some air in the cooling system.

Can I do the coolant bleeding again without reflush the radiator?
If I could, I'll try the bleeding first. If that doesn't help, I'll clean up the IACV and FITV again.

I really appreciate all the inputs, Cheers!

 

yes.

if you hae the srvice manual just follow the instructions on bleeding the air out and dont be afraid for coolant to run out. usually it will gurgle a bit out of the bleed bolt until you get a steady stream.