junkyardje

I have a throttle hesistation at a cold start and or under 20MPH I have replaced the following Temp sensor O2 sensors air filter fuel filter cleaned the cold start injector. I am at a loss.. I have done a search perhaps I am searching the wrong things. I checked the ECU and MAF they are both working correctly. It is not producing any codes..I have been banging my head off the wall about this for a week or so now...

GEORGE_JET

Which temp sensor did you replace, the one by the filler neck, or the one by the bellhousing?

junkyardje

the one by the bellhousing.. I didnt no there was an additional one.. could that be the problem?

llcoolpass

clean the insde of maf, especially on all sides of the door using spray carb cleaner let dry then change the cog [to overall lean it out] 2 notches, reisntall should be fine [withouthaving to turn the idle screw]. some ppl here were doing the screw turn thing but that mostly works I know but then I did the thing I'm recommending to you and it works.. but doing what I recommend worked fully. if that still not, then I would do the screw trick.

this assuming you have the maf issue common

i was posting here, but there may be more comments that aren't helpful in this thread now so yeah

http://www.toyotanation.com/forum/sh...d.php?t=244705

se p4

but p6 has this link, which is more vital in my opinion , and I did the mod at that link as well as cleaning, and now the car doesnt have the bog

http://www.toyotanation.com/forum/sh...ad.php?t=82158

GEORGE_JET

The ECU coolant temp sensor is located near the filler neck (by the timming belt), the one you replaced was either the fan control, or the instrument panel. Measure it at 70deg it should read 2~3 K ohms, at 180 is should read .2 ~ .4 k ohms (200 ~400 ohms). I would suggest checking this. IIcoolpass suggestion about the MAF is good, but this is well worth checking (cheaper to replace too). You mention cold start, how does it run when fully warmed up?

junkyardje

hey fellas thanks for your help.. I got it fixed from a link that LLcoolpass sent me.. he told me to advance the timing and lean out the VAF.. I was going to do that.. but I read in one of the replies that some one cleaned there VAF, EGR valve and IACV valve. This fixed there problem.. so I did the same took the EGR valve and IACV off soaked them in carb cleaner for like an hour.. also hit up the VAF again just for good measure.. Put it all back together and pow like new... how bad *** is that.. !!! I also added a new fuel filter just for good measure.. I had been bangin my head off the wall about this for a week... and now its fixed ... No more BOGGIN down!!! Thanks to all of you for all advise given...
Jimmy

llcoolpass

yeah i did all that and the only thing that fixed it was cleaning the vaf which soon there after i moded [lean] and adv the timing. glad it worked man, i told you it would probably work lol good thing it stopped raining today for you hah

12340987

So according to wikipedia Toyota detuned the 3vzfe until 1994, when it magically became a 200hp engine. Did they achieve this by enriching through the AFM and retarding timing the same way as described at TN?

I'm just wondering if these AFM flap springs get weak over time, and leaning the mixture only incidentally improves performance. Or is that what that cog does, stiffen the spring?

I would be doing this mod, but my plugs were really worn with white deposits, so I'm wondering if it was burning too hot already.

junkyardje

well I didnt do the leaning and advancing the timeing I just cleaned the IACV EGR valve and changed the fuel filter

llcoolpass

"So according to wikipedia Toyota detuned the 3vzfe until 1994, when it magically became a 200hp engine. Did they achieve this by enriching through the AFM and retarding timing the same way as described at TN?

I'm just wondering if these AFM flap springs get weak over time, and leaning the mixture only incidentally improves performance. Or is that what that cog does, stiffen the spring?

I would be doing this mod, but my plugs were really worn with white deposits, so I'm wondering if it was burning too hot already."

wikipedia might be correct but you are making many mistakes.
fits of all, the engine is rich and runs retarded, so if anything they would have leaned and advanced for the 94 to 97.5

secondly, the VAF meter involves a flap with a spring and a poteniometer. as the door opens, the voltage goes down . leaning the meter most likely just brings it back into spec since the door opens more easily with a worn spring -- implying to add more fuel.
the cog affects the spring, yes.

you probably don't know how to read spark plugs, so don't rely on your opinion. technically, anyone can do the timing and cog modifications if they have wideband 02 sensor and time, they can tune the car better. but, once the cold start, around 20mph bog starts happening, your meter has gotten really bad and the mod can only help you, assuming a new 500 dollar VAF is cost prohibitive for you. also, dirt and grime etc get in the VAF and cleaning it out makes it run proper -- not bog. cleaning and moving the cog a couple notches on high milegae older car 3vz-fe shld help it out in fuel economy and performance.

happy_es3

not to highjack the thread but ive got a 2000 and its starting to give me the hesitation and the bogging, is there any benefit from the mod (lean and timing) also if anyone has links to a throttle body/intake clean out diy that would be great off i go to search /resume thread/

12340987

Sorry, it will only work for ODBI engines. You may benefit from cleaning all those aforementioned parts.

I was thinking backwards, I meant to say "leaning" and "advancing."
I know what spark plugs are supposed to look like, and mine didn't look like them. They looked like they were ash fouled, only the deposits and electrodes were pure white. Now that I've changed them I should be able to get a more reliable reading.

llcoolpass

your 2000 has a 3vz-fe?

1234, your spark plugs sound like they could be good. white is normal on modern engines. but whatever

happy_es3

lol no llcoolpass it does not, sorry guys late night post must have been tired or somthing, still anyone have a link to cleaning out the throttle body/intake on a 3rd gen es?

llcoolpass

why would you need a write up for cleaning the throttle body.... i mean if you're that new to it, you're best served buying a haynes manual or if you like a little challenege/save money find the FSM on the internet for free. it's a matter of a few screws. sholdn't be that hard, but I do think you can find something about it if you search on this site.

the intake and throttle body you use a rag and spray carb cleaner

on the intake manifold you take it off and let it sit in a vat of degreaser

the hot wire mass air flow meter you would spray the spray that is labeled for that purpose at an auto parts store, cleaning the hot wire itself [but carefully as it is expensive and sensitive]