Blacktops when cold

[alamo]

My BZ-R Blacktop has this problem for about 3-4 min when it’s cold. Also my Silver top GT Apex used to do it too.

Just let your car warm up! And only use about 1/4 - 1/3 throttle. You should never hard rev a cold engine.

Don’t worry about it unless it's still there once the car is warm!

[astrae]

My BZ-R Blacktop has this problem for about 3-4 min when it’s cold. Also my Silver top GT Apex used to do it too.

Just let your car warm up! And only use about 1/4 - 1/3 throttle. You should never hard rev a cold engine.

Don’t worry about it unless it's still there once the car is warm!

2000 - 3000rpm is is hardly reving the engine. It become a problem when it won't go over 3000rpm and you are trying to drive in traffic...

Also I've heard a lot of people say leaving your car to sit and warm up does more damage to the engin because it doesn't have as much oil pressure.

I don't have time to sit and wait till its fully warm. Could take 20 mins in these winter temperatures. Mine hesitates when its about 1/4 warm. Not dead cold.

[demis]

wating for your car to warm up everytime you drive it is just not reasonable think of all the wasted time and petrol


they hesatate with the throttal only open a small amount and as said you dont have to be ringing the crap out of it ,it is around 3000 rpm

[malc]

noticed mine does it at about the same amount of revs, seems to be 2700rpm, sometimes a little less sometimes a little more.
Not always when its cold too.

[sergei]

I don't have time to sit and wait till its fully warm. Could take 20 mins in these winter temperatures.

It should take about 5min tops to warm up at any temperature, if it does take that long to warm I would suggest you to look at thersmostat, as it might be jammed half way open (very often happens). Running on half cold engine will generally worsen fuel economy, so by replacing $20 item you would save a lot more in long term (and the fact that windows will defog a lot faster is the bouns).

[dotdog]

When its 2 degrees outside it takes my blacktop bout 10 - 15 minutes to warm up, thats with a brand new gen toyota thermostat, I thought it was too long thats why I replaced the thermostat, but it seems to still be about that.

[NILPSI]

Ok....

I have had this prob ever since i got my car almost 3 years ago, When i got it it was standard all except the HUGE 4 - 1 Cusco extractors, it hesitates anywhere between 2500 to 3000rpm everytime unless you have your foot hard up it, mine does do it when its cold as have all other blacktops whose owners ive spoken too, of coarse the easy fix is dont drive hard till its warm.

I have however noticed that if i unplug the VVT solenoid it stops it and runs really smoothly just with a bit less get up 'n go.

I Have got an oil catch can (doesnt help), i did for a while have a homemade air/fuel ratio gauge in the car, this wasnt the most accurate thing but when i drove at about half throttle it would stay on the scale from the low end of stoich to about half way round rich, as soon as it hit 3000rpm it dropped right off the end of the lean side, then at 4000rpm it came back and hit the top of rich and stayed there!

I also had my codes checked and it seemed to be always throwing the ignition signal fault code? Checked 3 times at 2 week intervals and was cleared every time after they were checked

I have changed:

Dizzy Cap
Dizzy Rotor
Leads
Plugs
Complete Dizzy (was checked by auto sparky before fitting and showed it was fine)
O2 sensor
TPS
Removed the little filter thing in the MAP sensor vacuum line (thought it could have been blocked)
+ more stuff i cant think of right now

Now this problem has anoyed me for so long and im getting kinda used to my car doing it, However it still anoys the f**k out of me so if anybody manages to fix it please get in touch

Cheers

[TRD001]

Has anyone tried the TRD Thermostat?

If so any better?

[AceSniper]

how would that change anything apart from runing it cooler, I have run a cooler thermo but not much point unless hot summer..?
think the best answer is... why are you trying to go over 3k on a cold engine...

[demis]

the engine should run fine when it is cold, saying that you should wate for it to warm up or dont rev it over 3000rpm is not fixing the problem !!!

[astrae]

It looks like I have solved my hesitation problems. touch wood....

My oxygen sensor was giving off all sorts of funny voltages.

New one is in and haven't had any problems since.

Over the past couple of weeks i have done

new plugs
new fuel filter
new O2 sensor.

I'd say the only way people are going to find out their problems is to take their car in and get their sensors checked.

hopefully this is the last time i will have this problem.

[Elmendorf]

Mine doesnt hesitate at all and mines very stock. Only change been made to the engine is a trd panel filter

[dotdog]

Dont you run your blacktop on 91?

[Elmendorf]

Dont you run your blacktop on 91?

Depends on how poor I am. Either way mine runs fine on both

[dotdog]

Nice, mine pings on 98 LOL

[Mr Revhead]

i black top WONT run fine on 91
you will be down on power and getting crap economy

[Chickenman]

Nice, mine pings on 98 LOL

Same here with Alycia's car.

[ribided]

hi just joined a while ago and i've go a 97 bz carib, doing the same thing!done much the same changes as you guys have but haven't changed the o2 sensor yet.

hopefully somebody can figure this one out

[AceSniper]

yea check ya 02, I had weird voltages from mine ages ago replaced it... was all fine but its gone bad again, I dont know why... but the oxy loves to read lean when its bung = lotsa over fuel
I thought maybe it was the heater that was stuffing out but my new one still gets warm but its reading lean 98% of the time when driving

[sergei]

My genuine oxygene sensor on my AE101 has about 4 years, and still going as new. Instead of replacing oxygene sensor look into what is actually making them go rich and clogged up with char.

Clogged up oxygene sensors are easy to fix, with butane torch, also this process is good way to test them. Heat it up until it is red hot, it should output arround 0.9-1.1v at this stage (constantly). If it does not work, continue heating and cooling untill it does, if it still does not it is buggered (probably seen to much oil). Note don't test for resistance, as it might damage the sensors, in toyota usually heater wires are black. Try different combination, untill you get some voltage output on hot with gas on. You can use any hidrocarbon based flame to test that, but flame should be hot (blue), obviously don't use gas welder, as its flame is too hot and will damage the sensor. I've restored a few clogged up sensors like that...

There is a big misconception about functionaly of oxygene sensor: they do not output frequency, they only output voltage in presence of exceess hydrocarbons. What makes them fluctaute the voltage is the ECU operation - it constantly changes the mixture, and with narrow band sensors it is trial and error algorythm - leaner than 14.7 it goes below .45v richer it goes above, with really steep hysteresis.