Toyota 3S-FSE missing

I have a 98 Toyota Nadia 110,000km, with a D4 3S-FSE very happy with the car, recently replaced plugs cambelt water pump etc. I had hoped this would fix the persistant miss that occurs during the ECO phase of running (green light on), no such luck.
Running it on 98 octane fuel, giving it a hard run does help a little but only for a matter of a day or so then the miss is back when on a very light throttle. Any suggestions as to a cure!

driver_gammelvind, Mar 30, 7:53 pm

What colour were the plugs! Sounds like it might be a fuel issue. Although with those direct injected things it's not as straight forward. I'd maybe look at the fuel filter and such for a start.

The other thing is pull the engine codes, it might tell you it's just a coolant temp sensor, TPS or something

driver_pollymay, Mar 30, 8:00 pm

The plugs were a little dirty, but not bad for 100,000km Pulling codes is not something I am familier with, understand the principle just don't know how. I come fom the days of vacuum ballancing twin carbys lol.

driver_gammelvind, Mar 30, 8:07 pm

Basically it will need a scan to pull the ECU error codes. Older cars could do it with a paperclip. Newer ones not so much, a dealer can do it. They will more than likely try to upsell you to fixing it at their shop but you can just ask for a scan.

driver_pollymay, Mar 30, 8:09 pm

More likley to be a carbon issue. When the engine goes into ECO mode it pulles off a very learn burn. something like 17.8-1 so it has a tendincy to hunt or surge during this time and a there is an amount of surge that is normal under ECO but carbon build up in the inlet mainfold from the EGR system will cause the surge to be more agressive.
Also the air fuel ratio sensor in the exhaust manifold could be on the blink this also causes the same agressive surge.

driver_gadgit3, Mar 31, 9:20 am

if it hunting when going into lean mode it could be o2 sensor playing up making the ECU alter the mix to get it right

driver_n3d4sp3d, Mar 31, 9:35 am

Yea in the case of the 3S-FSE it's a air fuel ratio sensor. The o2 sensor is fitted after the cat converter just to sense if the cat is doing it's job or not.

driver_gadgit3, Mar 31, 9:41 am

It's more of a miss than surge, I thought new plugs would fix the problem as that is what it feels like. Then again that could just be semantics, one mans miss is anothers surge.

driver_gammelvind, Mar 31, 9:45 am

Yea when you say a good hard run makes it better for a day or so kinda makes me lean toward the carbon issue as it is a common one. But without driving the car I couldn't rule out an electrical miss

driver_gadgit3, Mar 31, 11:05 am

Would dismantling and cleaning the throttle body help, I know it made a huge difference to my Lucida.

driver_gammelvind, Mar 31, 7:52 pm

You could give it a go but the carbon tends to build up in the inlet tracks rather then round the throttle plate and idle ports.
I have done a few and it's normally a good 4-5 hours work. pulling the inlet manifold off and cleaning it as well as the the ports and around the valves (what you can get to).

driver_gadgit3, Mar 31, 8:28 pm

without being ignorant are the correct plugs fitted I work at mitsi dealership and the GDI's miss like crazy when incorrect plugs fitted.

driver_n3d4sp3d, Apr 1, 10:42 am

blocked cat converter!

driver_steve98h, Apr 3, 6:09 pm

I must ask, had a local garage install them, while they were doing the cambelt etc. Takes a couple of hours to get the manifold etc etc off in order to get to the plugs, prick of a design.

driver_gammelvind, Apr 3, 6:48 pm

Wouldn't that miss right throughthe rev range, rather than just on the eco stage!

driver_gammelvind, Apr 3, 6:49 pm

seafoam worked in one for me - was a corona same engine etc

driver_zephyrheaven, Apr 3, 6:51 pm

Seafoam! Having visions of a trip in the surf lol

driver_gammelvind, Apr 3, 7:22 pm

Wouldnt hurt lol
Someone on here selling it now too, I got mine from BNT

driver_zephyrheaven, Apr 3, 7:44 pm

Well that looks an interesting option to try, just checked the website.

driver_gammelvind, Apr 3, 8:22 pm

Subaru used to & maybe still do make their own version, works ok

driver_zephyrheaven, Apr 3, 8:23 pm

Errr you sure! I didn't think the Corona was new enough to get the FSE, just the FE/GE engines.

driver_timmo1, Apr 4, 8:55 am

Corona/Preimo 97-2000 had the D4 engine fitted

driver_gadgit3, Apr 4, 9:21 am

HT leads have to much resistance

driver_redbluecod, Apr 4, 4:52 pm

The 3S-FSE dosnt have HT leads. Direct spark coils.

driver_gadgit3, Apr 4, 5:07 pm

Yeah it was

driver_zephyrheaven, Apr 4, 6:25 pm

3s-fse D4 are renowned for there misses just talk to a toyota technician,run some injector cleaner then sell it!

driver_adogg, Apr 4, 8:35 pm

Update. Missing has been continuing despite a really good dose of Seafoam, did help a little.
Yesterday while doing an oil change, thought I would have a really good look at the throttle body, noticed a bolt missing off the manifold. An hour later (lots to remove before you get to it) had the plenium off inc the throttle, talk about carboned up. Not a wonder the seafoam didn't do much, there were blocked holes and heavy carbon. Lots of scraping, poking, carb cleaner spraying later all clean, well as clean as I could get it. Reasembled and what a difference, one hell of a lot of performance and 90% of the miss gone, guess the seafoam might fix that.
Thanks for all your suggestions, at least I know how to get the plugs out now.

driver_gammelvind, Dec 9, 9:44 am

this is a problem that mitsi have as well.sometime ago in another thread I suggested dripping a metered supply ( at or near the thottle body ) ofsolvent to stop intake carbon
diesel would do !

driver_the-lada-dude, Dec 9, 1:41 pm