Hesitation on my V6 Collie

[AndycruiserguyLomas]

This might require a bit of help from overseas where the V6 Prado/Colorado is a bit more common.
The Collie starts up and runs fine but when it's warm it has a hesitation for a second before it sets off from a tickover, as you would set off from a junction or entering a roundabout from a standstill. After the slight hesitation it sets off with plenty of power and above tickover it runs fine. It feels like the enrichment it needs isn't there for half a second.
It will do this if it's stood with the bonnet open and you manually snap the throttle open.
The plugs have done less than 20K.
Although its ODB1 it has been scanned and showing nothing amiss although it is basic.
It's run on Shell V power nearly always.

As I understand it enrichment is achieved by drawing fumes collected in the charcoal canister opened by a valve when required, I may be wrong on this but the valve works and when powered up remotely it makes no difference. The inlet pipe to the canister the rear isn't blocked and when the canister is bypassed completely ie.connected straight to the inlet manifold it still hesitates.

I may be looking in the wrong place as I don't understand the workings of the V6 as I do the diesels but do understand the fundamentals.

There may be a simple solution to this I just need pointing in the right direction.

I think there is a fuel filter somewhere along the line I replaced 20K miles ago which I might investigate.

Back to the drawing board as they say.

Thanks.

 

[stumog]

Does it have a airflow meter or something similar? I have had problems on similar age golfs where the afm needs a clean. Also problem with a vaccum line having a slight crack that closed up with more pressure

 

[AndycruiserguyLomas]

Yep it has a MAF sensor, like a 2 wire thing. I can't see any perished vac lines, there aren't a lot on it TBF.

 

[MODVRS]

When I had idling issues with mine it was down to a clogged up IAC valve (idle air control) and a bit of carbon build up around the throttle butterfly. If it's not been cleaned in a long time it might be worth popping the throttle body off and giving it a good clean. The IAC is on the bottom of the throttle body and has coolant pipes on either side.

 

[AndycruiserguyLomas]

This sounds like somewhere to investigate, many thanks.

 

[MikeJak]

I have the V6 too, it does need a bit of throttle on take off but no real hesitation.
they are relatively simple engines... air-sprak-fuel are
air is pretty easy, check the air filter is clean, clean the maf sensor (can make a big difference) cleaning the IAC valve under the throttle is also a good call. the butterfly is less likely to need cleaning as long as your CVP on the valve cover is working, you shouldn't get much oily air in the throttle and upper plenum at all.
o the back of the throttle body you have the throttle position sensor, mine was giving a laggy feel when the sensor went but it does store a code if the sensor is outside teh paramethers.

spark I assume is good if you don't have any misfires?

fuel is a bit trickier as it's deeper in the engine, I don't have much experience with that but read that running some injector cleaner regularly does help. I haven't done it yet.

the 5VZFE is very common in the USA, Tacoma and 3rd Gen 4Runner (and a few others) run it so there is a lot of info in state side forums.

 

[AndycruiserguyLomas]

Well, having well thought about it and going back to fundamentals I thought this must be a fuel issue. Having steamed out all the old petrol in the tank when I bought it years ago I thought about what I hadn't done, having replaced the in tank fuel pump.
When I serviced it up I didn't change the fuel filter. One dually ordered from Amayama ( £48.00) I fitted tonight and Hey Presto smooth running was restored, beautifully smooth again and no hesitation.

I'm back in love with it.

Next job, air con.