Blacktops when cold

[ROBODISCO_20v]

Anybody priced up NGK/NTK O2 sensor?
I just had a look in their 03/04 cat & it only has a listing for the 16v; OZA401-E70

[matt dunn]

Anybody priced up NGK/NTK O2 sensor?
I just had a look in their 03/04 cat & it only has a listing for the 16v; OZA401-E70

I can do the 4 wire NGK sensor
(does not come with a plug but you have to connect your old plug to it)
for $120 + freight.

Matt

[matt dunn]

Ok, for those watching this topic and having the problem,

Try running the car with the TPS disconnected and see if the problem goes away, and no the TPS wont be faulty.

Matt

[97ae111]

Hey guys, Here are a couple of hints to solve your problems, easiest and cheapest first. Disconnect your vvt-i solenoid, drive the car, if the problem is still there it is not the vvt-i. 99% of the blacktops problems are with the vvt-i. if you dont hesitate then take out the vvt-i solenoid (2 10mm bolts, and the solenoid is on the left side of the exhaust at the top of the block. Check that the spool moves freely, if it doesnt undo the circlip, remove the spool clean and reassemble, refit and drive happy.
In the unlikely event that this doesn't fix your problem, remove the top cover for the cambelt and check the vvt-i cam sprocket for any signs of leakage. if it is even slightly moist then it's stuffed and you can kiss $1000 good bye. I did the later first unfortunately.
Let me know how you get on

[Mr Revhead]

2 things

VVT-i isnt found on a black top.

and $1000 my ass

[matt dunn]

my $1000 buttocks

And I heard you were cheap,

The problem won't be the solenoid or the cam pulley as they work fine hot and they are not temp related.
From my testing it is a design fault in the programming of the ECU.

You can fool it but not fix it.

Matt

[97ae111]

No offence Mr Revhead, but my 20v blacktop with VVT-I would beg to differ on your comment. Matt the temp releated issue can be with the solenoid as with different temps there are different clearances in the spool, which may or may not cause it to stick. your comment about the ECU could also be true, as i have just found this article relating to blacktop ecu issues, http://www.my-acoustic.com/Car/ECU/20vM ... roblem.htm

P.S part number 13050-16020 VVT-I sprocket $795.00 retail and $200 to fit it. When young and dumb your wallet is never full

[Mr Revhead]

20vs use VVT, not VVT-i
VVT-i is a later system.

$750? ok im going to up my price!

[RedMist]

No offence Mr Revhead, but my 20v blacktop with VVT-I would beg to differ on your comment.

Revhead is right. Although his fetish for Goat Porn is wrong completely wrong.
Although there is a tonne of complete and utter rubbish on the web in regards to the blacktop being VVT-i it most certainy is NOT. i gives the ability to continuiously vary the cam timing, ie not an on/ off situation but modify the timing by a few degrees at a time. The electronics and mechanical components simply dont exist on the Blacktop. The blacktop is a copy of the silvertop VVT with a different solinoid.

[solidog]

Thats what it is right, so everybody agrees, its not backfiring/misfiring, its hesitating around 3500-4500rpm. Id rather call it a 'hole' in the 'power curve', cause it sounds cooler, and its a more graphic description of the issue!

i've owned my94 20v from 30k - 125k current, brought off toyota for a grand sum, anyways, i've thrashed the arse off that girl like you wouldn't believe, and YES i'll stab the throttle with a cold engina! Don't mistake me for a total idiot, im well aware of the cincequences and do very regular oil/filter changes and general maintenance (if it shouldn't or couldn't, it wouldn't, and it takes it!). They are strong, without a doubt, in my view bulletproof! However, like all things they age and things deteriorate. Thats when you get multiple issues, and overlapping faults.

My motors eaten a clutch and only two sets of pads?!, CamBelt & WP @100,00, but generally all maintenance stuff, I got into the trade art the right time clutch & cambelt combined cost me around $600

Back to my point, my 20v has the hesiation at almost the same rpm the vvt is supposed to actuate, around 4400, and this lead me to thing a blocked oil gallery or faulty actuator? recon theres any truth to that? I also have a faulty speed sensor or tacho as the gauge sometimes reads 10k off and sometimes goes nuts! I scoped it on a hoist with no joy, im sure its only breaking down under load, mabey related, but i don't think so. (No fault codes with scantool either)

My levin is mostly stock, 'cept a pod and real gas* (*98!) but it'll reach terminal velovcity in 4th at 8200RPM! I love it!

[sergei]

rpm the vvt is supposed to actuate, around 4400...

How many times it has been said that VVT is not VTEC and does not have certain rpm turn-on point. It can activate from IDLE speed if you nail the throttle (providing the car is warm). Other point is that the hesitation happens when VVT is certainly not switching on because the engine has not reached operating temperature.

[Mr Revhead]

as above
it is NOT RPM switched

[slighty_sykotic]

as above
it is NOT RPM switched

lol. but vvt/vtec is cooler if it has a rpm swtich point....
Then they go put in a vvt light and think its broken because it comes on all the time.....



Anyway, another interesting point... My freshly rebuilt blacktop didnt have this problem... It did before I rebuilt it (rings were shot tho). In the rebuild the only new parts were bearings and rings, the rest was just cleaned. (o2 sensor was NOT touched).

Afaik, it shouldnt have made a difference, but it did. It cured it.

(i havnt driven that motor long, i sold it a long time ago after I had done aroudn 20tho, and i don't know the current owner so I can't check if it still does it).

--Sykotic

[johntramp]

VVT vs VTEC

[Mr Revhead]

as above
it is NOT RPM switched

lol. but vvt/vtec is cooler if it has a rpm swtich point....
Then they go put in a vvt light and think its broken because it comes on all the time.....



Anyway, another interesting point... My freshly rebuilt blacktop didnt have this problem... It did before I rebuilt it (rings were shot tho). In the rebuild the only new parts were bearings and rings, the rest was just cleaned. (o2 sensor was NOT touched).

Afaik, it shouldnt have made a difference, but it did. It cured it.

(i havnt driven that motor long, i sold it a long time ago after I had done aroudn 20tho, and i don't know the current owner so I can't check if it still does it).

--Sykotic

that would point at the dirty fumes in the intake.....
something i know silvertops hate

[matt dunn]

Anyway, another interesting point... My freshly rebuilt blacktop didnt have this problem... It did before I rebuilt it (rings were shot tho). In the rebuild the only new parts were bearings and rings, the rest was just cleaned. (o2 sensor was NOT touched).

Afaik, it shouldnt have made a difference, but it did. It cured it.

Earlier on in this thread I posted this.

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.


It may be that you have got rid of the blowby past the worn rings and have cured it??

[Mr Revhead]

sounds good to me

[Voyeur]

Hey guys, long time watcher first time poster.
My vehicle does the same, and it's doing my head in, so i have hooked up every kind of gauge you can think of, here are my observations.
When you crank the starter, the vvt operates untill the engine fires (presumbaly to allow in more air, about 3/4 second in my car)
from there the vvt will not operate again untill the water temp is about 50 degree's. Once up to temp the vvt will kick in at just about any rpm range, i have noted any where from 1400 right up to 7100, but only when the manifold vacuum is between 0 & 5 inches. I know that the TPS, and speed sensor have nothing to do with vvt, as when you disconnect them vvt still works. The blowby is a good theory as this would alter the manifold pressure. To see if this was true I fitted a restricter in my pcv line last night, and while this helped with low throttle cruising (100 km at 3000rpm ) it made no difference to mid throttle acceleration. Does this give anybody any ideas.

[Mr Revhead]

good stuff.

when you say:

it made no difference to mid throttle acceleration

do you mean it still does the stutter thing? or something else?
just confirming

[Voyeur]

To be more precise, at 25% throttle from standing, or at cruising (about 15% throttle?) the problem has gone. At 30 to 70% throttle the problem is still there, also the lite decelleration from 100km is still jerky. My thoughts are that this is related to cam phasing by the vvt. so i will play with the size of my restricter tonight. it is about a 2.5mm hole at this stage. Does this sound feasible.