Vvti Flat Spot

[bigblue2]

Hi folks new to the forum and to celica ownership, i love driving this car and around town its great, my problems seem to be when i get on the open road and take it higher up the rev range, driving relaxed and below 3000rpm it drives perfect, if i try to accelerate hard it just doesn't respond and pick up is very slow and appears to come in surges, if i go to around 4500rpm then change up there is a definate flate spot after gear change, it seems fine while cold, i have cleaned the icv and the maf , changed all filters and oil, i tried the old method of unplugging the maf and trying it and it was pretty much un driveable unless i feathered the throttle, once reconected it drove ok again (whith the flat spot still there) but threw the eml on , i cleared this by reseting the ecu, this problem is ruining a lovely car for me , can anybody suggest any issues that may cause this?, it has 112k on the clock and the previous owner put a stupid resistor (gain 25hp !!!!!) type perfomance "chip" , i swiftly removed this and it drives the same with or without it , i hope someone can offer some advice

many thanks

p.s it's a 2001

[funkyhouse]

Hi mate

I have just posted a simliar issue just before yours. mines a facelift t sport with just 41k on the clock. flat as pancake through all the mid range and trying to drop gears to overtake is embarrassing i STRUGGLE TO GET TO THE 6K TO ENGAGE LIFT. You might have to tell them the model of yours 140 or 190. Toyota Garage when i took it to service said there was nothing wrong. Good luck with your query great looking cars and handling is good but pointless if you have to pump gas pedals etc get any sort of accelation. Mine is also top speeding 110mph supposed to be 140 not enjoying the toyota experience so far.

[bigblue2]

mine is the vvti so no lift to give it the extra kick, just as a purely none scientific experiment we tried to 0-60 on a flat main rd near me , it was only done with a spo******ch on a phone but it was 18 seconds!!!!!, its crazy as it hits 3k so easy and picks up well its just after that it goes very pear shaped, just been trying to find good specialist near here so they can give it a look over as my cheapo scanner won't pick any codes up

[edwardio]

Very strange. What the fuel usage like?

When you say you reset the ECU, did you just clear the code or did you pull the fuse/disconnect the Battery?

Plus as you have a pre-facelift check you oil on a weekly basis.

[junebug1701]

Hi folks new to the forum and to celica ownership, i love driving this car and around town its great, my problems seem to be when i get on the open road and take it higher up the rev range, driving relaxed and below 3000rpm it drives perfect, if i try to accelerate hard it just doesn't respond and pick up is very slow and appears to come in surges, if i go to around 4500rpm then change up there is a definate flate spot after gear change, it seems fine while cold,

p.s it's a 2001

Do you have the 2ZZ-GE engine? If so, it could be a problem with the VVTLi lift bolts:

http://www.billswebspace.com/liftbolts.pdf

[bigblue2]

thanks for the responses, its a 140 vvti so no lift , i just disconected the Battery to clear the eml, i borrowed a friends code reader today i was hoping to find a fault code stored but nothing, on a run driving steady (2500rpm) in sixth it does about 30mpg around town again driven gently its about 26mpg, a friend of mine has one the same year and pulls much better and uses much less fuel she gets high 30s on a run, i keep thinking back to the maf as it had that stupid resistor on it before, but from past experience with other makes usually un plugging it will clear the problem, do toyota's work the same? and plus i know from other makes they don't always throw up a fault code for maf issues, confused now!!!!!

the oil was changed within a hr of buying it and so far in 600 miles not moved down the stick , but will be closely monitored, its a tiny bit tappy on the top from cold but very sweet within a mile or so , i was amazed just how small the oil filter was though

[edwardio]

Another suggested would be to get your mate round or you round his & borrow his MAF sensors. Fit it & reset the ECU, then take it for a drive. If that solves the issue, then you need a new MAF.

If the problem persists, then something else is the cause.

My only concern is this resistor. some damage might have been done to the wiring when they fitted it.

It's obviosuly over fuelling, so it might be an O2 sensor issue. Even cruising around at 2500 rpm in 6th (providing you're not carrying a lot of useless weight in the car), you should be able to hit the combined mpg figure of 34.

I'd try with your mate helping you out:

Switch MAF sensors

If no joy, switch the O2 sensor 1 at a time.

Basically try to rule out as much as possible without spending cash.

[bigblue2]

thanks

all makes good sense , the resistor thing was bullet connected rite by the maf and it was one of the dial type and of course it was upto max , do folks really believe you can get all this extra power for just a few quid its crazy .

i will look into the 02 sensor issue also as there seems a few folks had issues with those , the only thing throwing me is there is no codes stored.

there is a specialist jap breaker not to far away with a few celica's in so at least if i have to keep trying other bits i can go down the second hand route ,

thanks for the advice

[edwardio]

Stupid people believe you get the extra BHP on top of the cars normal power. All they do is give you (although mildly) more of the cars existing power as it tricks the ECU into thinking the air is colder than it actually is.

[bigblue2]

i have now tried using a maf i know is good and restting ecu etc, it made a tiny difference but not fully cured the issue, gave it a good hard run a few red line blasts too,if i held it in high revs you can feel the power dropping off then coming back, still no codes, tried a run with maf not connected and couldn't even get out of the road it drove so bad, one thing that has come to light is after a hard run there seems to be carbon on the rear bumber, we thought it was oil at first but but its dry and dusty, from that i'm thinking blocked cat perhaps???? , i have looked at the 02 sensor change but was pretty scared by the cost of buying the 2, is there anyway of testing them? or do they ever bring up a code, if i need to change them to cure the problem so be it but not keen to just change them and find no difference.

was chatting to a toyota breaker and he said he sells a lot of oil control valves, he suggested these may cause a performance problem due to not proper oil flow to vvti unit, is this the case? , he did admit to not being a mechanic himself but its the feedback he has had from folks who are buying from him