Blacktops when cold

[rallymazda]

My symptoms just feel like someone someone pulls the handbrake 1/2 on for that rev range when cold.
Not a miss or anything.

yep

[Lanius]

sounds about right.

[demis]

i thought it could be was the nock sensor

any other idears ??

[AceSniper]

un even fuel presure? factory the vacume line on the fpr is off one cyl (unstable)

[dotdog]

Yea it does feel like someone has pulled on the handbrake, and mine isnt a miss its just like the motor doesnt want to go
Ive got brand new trd leads on mine and my plugs are only 15000km old. How do you clean out the t/bs?

[Dell'Orto]

Take it in to Tony and go "Oi, clean these out"


Nah, just take off the plenum and trumpets, and blast em with some carb cleaner.

[Miss_Trueno]

Same symptoms as mine. I've found nothing to cause it, nor has a mechanic. I baby it when it's cold, try to change really low.

[demis]

i still think its the shit fuel we get here

[matt dunn]

Here was the original theroy on the catch can fix.


When the pistons are cold they are smaller, and let more blow by past the rings pistons etc into the sump.
This then enters the engine via the PCV system and enters the combustion chamber where the oil vapours cause detonation.
The ECU senses this ( only in the most detonation prone zone which is the RPM range where this ocours) via the knock sensor and retards the ign timing. This causes the lack of power, or handbrake is still on feel to the car, during that particular rpm range and only when cold.

As said earlier, some have tried catch cans with no effect, so this may or may not be the case.

On my particular vehicle it only really occours in the first 4 minutes of each day then will not happen again untill the next day, or the car is left for more then 4-5 hours to cool. This makes it a bit hard for me to check, as the wife takes the car to work each day, and I am not getting up early to try and checkm it before work.

As I have acess to a scan tool the shows about 50 lines of current data out of the ECU, one day I will get around to it and examine the problem thoroughly.

Matt

[dotdog]

Yea mine is smillar its for about 2 or 3 minutes after the car has been sitting cold for about 5 or so hours.
Has anyone trying retarding the base timing to see if that makes it go away? cause mine is still running the facto 10 degrees

[demis]

apparently the resitance test is not that relible

[gt20v]

i have the same prob except.it only happen from 2k to 3k rpm..after that it will jump and pull hard.........

any info from your test demis?

[Chickenman]

Same thing in Alycia's car but only really noticable in the last month or so (since it got colder... duh! )


It's all good though, shouldn't really be pushing a b/t cold anyway... think of it as a reminder.

I will say, the engine sounds better off vvt at mid range rpm. Then again, we haven't spoiled the car by putting on a fart cannon.. just some pink stickers (no.. it wasn't me).

I saw someone racing his BZR last night (grey levin) after I watched him put 91 in it... don't buy that one

[offensive]

when my car was running with a silvertop ecu, it would hesitate, pop splutter then take off when warming up, and pretty much run really bad. Replaced the ecu with a blacktop ecu and it runs sweet now. throttle bodies were cleaned, TOM'S trumpets and plenum chamber are all thats really been changed along with ecu.

only thing that slightly bothers me now is now the weathers getting colder, it idles at nearly 2 grand in cold mornings

[RAZA]

About a year ago mine was doing it, and there was a thread on here about the same thing.

Everyone seemed to be saying that cleaining the TB's fixed it for them, I cleaned mine and it fixed it on mine.

I see some of the people above have tried it and it hasn't worked for them, but if you have this problem and haven't tried cleaning your throttle bodies it might be worth giving it a go.

[Mr Revhead]

how many ppl having this issue are running washable filters?

[Lanius]

Mines running trumpets, and has the same issue. Not so much a hesitation as a bad flatspot on mine tho. Once shes warm, it completely disappears.

[dotdog]

Ive got a hks foam filter on mine

[B1NZ]

Ive got a hks foam filter on mine

snap

[demis]

mine is running a toyota air filter int the factory air box

the engine is completly standard


cleanded t/b twice dosent make any diffrance
=