Toyspeed.org.nz Message Board

by **dotdog** » Thu May 04, 2006 7:25 pm

Hey all, my BZR levin seems to hesitate alot when its cold, it sorta revs to about 2.5k and then it almost feels like its missing, Is this pritty common? any way to fix it?

Website · by **Rick** » Thu May 04, 2006 7:34 pm

This happens to my mates blacktop no solution yet I think its quite common, where as my blacktop doesnt hesitate when its cold but it has a missfire which which I cant fix just about replaced everything on the dam thing.

by **slammed_integral** » Thu May 04, 2006 7:38 pm

could possibly be a earthing issue, go round tightening up all the grounding points. expecially by the intake manifold, injector area

by **dotdog** » Thu May 04, 2006 7:41 pm

mine has only started doing it in the last 5000kms

by **matt dunn** » Thu May 04, 2006 8:44 pm

Apparantly fitting a catch can fixes it.

Mine does it but have not got around to fitting one yet to see if it does work.

Matt

by **dotdog** » Thu May 04, 2006 8:59 pm

Ill try taking the breather out of the intake pipe then and ram it in to a coke bottle and see if that works

by **Miss_Trueno** » Thu May 04, 2006 9:21 pm

My blacktop does the same, hesistation when cold as does my friends. Never did figure out the problem...

Website · by **Rick** » Fri May 05, 2006 12:28 am

matt dunn wrote:Apparantly fitting a catch can fixes it.

That has been tried but it didnt do anything to fix the hesistation.

by **dotdog** » Fri May 05, 2006 7:52 am

Cool, seems like a pritty common problem anyway, someone must of firgured it out LOL

by **Lanius** » Fri May 05, 2006 10:44 am

Yeh I've noticed the same on my blacktop. When cold / still warming up, it seems to have a pretty bad flat spot just below 3.5 to 4k rpm. Once warmed up, she goes fine (have got a catch can fitted). The engine was very thoroughly serviced (everything short of a rebuild) before being installed, so I don't know if its anything that basic maintenance can fix (such as cleaning throttle bodies etc).

by **rallymazda** » Fri May 05, 2006 11:02 am

mine does it as well
maybe a computer controlled thing so you dont thrash it when its cold????

by **Lanius** » Fri May 05, 2006 11:33 am

Guess we need to hear from someone running a blacktop with an aftermarket ECU

From memory, the Sard ECUs were aimed more at silvertops than blacktops (I stand to be corrected however), so not sure if anyone on TS is using one with a Blacktop ... ?

by **overkill** » Fri May 05, 2006 1:25 pm

i have no real exp with blacktops, but, are the vvti systems oil pressure dependent?

coz pressure/volume of oil would be lower when colder. whether or not this affects an oil pressure sender/switch (or even a faulty one) + vvti at low rpm im not sure..

just a thought. sorry if that sounded stupid.

by **TrouserFxGt** » Fri May 05, 2006 1:28 pm

I would imagine that it has some thing to do with the computer not activating the vvt until there is a certain engine coolant temp.

by **overkill** » Fri May 05, 2006 1:33 pm

TrouserFxGt wrote:I would imagine that it has some thing to do with the computer not activating the vvt until there is a certain engine coolant temp.

yea but

dotdog wrote:mine has only started doing it in the last 5000kms

by **sergei** » Fri May 05, 2006 3:16 pm

In case of Lanius' 20v, the inlet was clean when we fitted the engine, and I'm sure I've checked the throttle position sensor. BTW black top throttle position sensor does not have wire for IDL switch, so it makes easy to set it properly, wich is just setting it to 0.5v.
The only thing I can think off getting upset after a time is the thottle position sensor. And maybe oxygen sensor, but gathering from what people said the hesitation also occures at WOT, so oxygen sensor should not affect that.

I had hesitation problems with my silvertop, it happend on light to medium throttle in 3-4krpm area, also on slow transition from full to closed throttle. It was fixed after replacing ignition coil. At night I could see corona inside it, also I could hear discharge sound coming from it, but the car was driving fine apart from flat spot.. I suspect that spark was weak under high chamber pressure (which I assume is the highest in that rpm range, due to the engine being most efficient there).

by **AceSniper** » Fri May 05, 2006 7:06 pm

im using a sard ecu with silvertop loom on a blacktop... no problems, but I do have a pcv catch an TB's are clean

by **matt dunn** » Sun May 07, 2006 7:01 pm

overkill wrote:coz pressure/volume of oil would be lower when colder.

No, oil pressure is higher when cold as the oil is thicker.

by **vvega** » Sun May 07, 2006 7:10 pm

id be going the lead/plugs/cap/rotor/coil/ignitor path
typically you have higher cylander pressures when your engine is cold

so is a little harder on your ignition system

v

by **matt dunn** » Sun May 07, 2006 7:18 pm

vvega wrote:id be going the lead/plugs/cap/rotor/coil/ignitor path
typically you have higher cylander pressures when your engine is cold

so is a little harder on your ignition system

v

I have the same issue with mine but have not looked into it basically because I dont drive it that much and I dont have the time at to track it down as it only does it when cold so you dont get much of a chance.

My symptoms make me believe it's none of those.
My symptoms just feel like someone someone pulls the handbrake 1/2 on for that rev range when cold.
Not a miss or anything.

Is that the same symptoms you others are getting?

Matt

Toyspeed.org.nz Message Board

Blacktops when cold

Blacktops when cold

Who is online