MA61 5M-E Spark Plugs

[ivandude]

5ME has no O2 sensor, that's 100% correct.

Patrickleslie, sounds like you got the main stuff checked but unfortunately it can never end chasing it down haha. What are some more details/modifications if any of your car? Few ideas of mine...
- look into your exhaust system, and the catalytic converter. If your 5ME MA61 uses one, try having it swapped out for a new unit, has been known to fix some economical problems
- how are all your tyres (stock size?) and correct air pressure in all of them? if theyre low (or even one really low) then it can have adverse affects.
- what type of engine oil do you use?
- replace the fuel filter & air filter (to good brand items if not already).
- notch the AFM (guide is on the webz look up "5MGE AFM notch")
- mod the air intake to get in more colder air (try driving around with a pod for a full tank see if any different, then enclose it or get some cold air tubing to it) (easy to get ideas googling "DIY CAI" ideas)
- extractors will apparently improve economy sometimes.. i found 5ME ones for $70 once, fitted em, didnt see any difference in economy but i did also remove some EGR gear + remove the stupid air pump. (remove that air pump yo)
- it sounds like you had a lot inspected but in case the injectors werent actually serviced (not JUST inspected), then get them serviced.

I've only had the Supra for 2 weeks and after doing 424 k's it took 51 litres of fuel.

This works out to be 12L/100KM and that's alright. The MA61 is a nice car, albeit fuel economy isnt the best in SOME of the old 5ME's. 12L/100KM this is the same fuel economy of a turbo Supra/Chaser/etc. The factory figures for L/100KM in Aussie mags reviewing the MA61 are pretty much about the 10-12L/100KM as well, so wouldnt worry to much.

I used to fill up between 50-55L in my old MA61 5ME Auto and always returned about 450-500km. I figured that was good for its age & condition (300,000km+ engine/body) to be honest. Mind that this is city driving figures on 30 yr old old fuel injection technology (the 5ME fuel injection is more or less the same as the M-EU and 4M-EU tech re-used from the late 70s..). I do remember long high way trips keeping <100km/h (p plate restrictions) went well, I got over 600km to a full tank once. I suppose just luck of the draw how it goes, and what kind of condition all the engine components are in.

[patrickleslie]

I didnt think there was an o2 sensor, I just assumed that he meant the AFM

No mods besides the exhaust as far as I can tell. I'm swapping in SA63 front suspension for extra camber, track and steering, with king springs and excel g shocks all round in the next two weeks.

- No Cat
- Stock rims with stock sized muchos cheapo tyres at the same pressure as on the placard. I was thinking of bumping the pressure up a few psi and seeing what happens. Tread is acceptable, probably 6 months left on them. I also have some 16x7 with almost new 215/50 Achillies ATR Sport but have never fitted these to the Supra.
- currently Nulon 20w50 oil. I changed that and the filter the next day after I got the car. I'm waiting to hit 5000km before changing it out for a different weight oil, not sure what oil grade to go with next change though
- Air filter changed the same day as the oil but they didnt have a fuel filter in stock at my local at the time. I'll be changing that on Thursday
- notch the AFM like this? (5MGE but it cant be that different) I'll waiting on an Air/Fuel gauge in the post before I fiddle with that.
- Cold air piping is on the list of things to do but not in the near future
- Seems to already have extractors/exhaust, can't read any brand markings on it. All the emissions gear is still fitted and the air pump makes weird puff noises under heavy acceleration. Definitely time to get that stuff out!
- Injectors were not serviced, but has had 2x Wynn's injector cleaner and 3x flashlube in the 8 tanks I've put through since owning it. Seems to run smoother but not more economical.

Cheers Dude

Patrick

EDIT: I also need a new clutch which is in the post too, the pedal is sloppy but it isn't noticably slipping unless you throw it hard in 1st and 2nd. Could this affect the fuel economy that much?

[ivandude]

Unfortunately I wouldnt know about the clutch/manual part 100%, I am not a manual driver, but from sounds of it I dont think it would.

AFM link looks right - I never tried it myself at the risk of resetting the spring/clip thing incorrectly. The guys on CelicaSupra forums mention this mod here and there so if you need pointers googling with the forum name + AFM trick should bring up more info about doing it.

Everything sounds okay but the injectors can use a proper service with them being taken out and investigated further, cleaned up from there. I think it costs like $30 per injector or something at most garages (off top of my head). Injectors, and the air pump. I dont know how much the air pump being taken out will improve, as it is only using a few HP from the engine upon start up to dump some kind of air into the exhaust mixture, thus making the 5ME aus-standard compliant for pre 1986 lol. Best bet is a good clean up on the injectors.

The M engines arent common these days & mechanics do know of em but no one really cares about saving much fuel, I dont think ull find many opinions on improving it, there is a few threads on Toymods already if u google 5ME Economy, for more ideas. Besides the regular stuff and maybe some more specific things to the 5ME, you'll probably end up at the stage to replace / rebuild internally and at that stage it's not worth it IMO... The engine will run fine, as you said it is, but its cost guzzling is hard to overlook. The savings from a budget conversion (even keeping the auto there), would save you more money in the long term keeping it, than the few hundred to save bucks on the 5ME. A 2JZ-GE powering it would easily see 500km+ at minimum on short city driving trips.

[Bitsa]

HOLY MOTHER OF SUPRAS, PLEASE TELL ME HOW TO GET 12L/100km!

Bitsa you have no idea how much I envy you right now lol

I've been getting +16L/100km in my '84 5M-E, I've tried driving nicely, I've tried driving angrily, I've high octane fuel, low octane, got my local car shop to bump around the timing, injector cleaner, flashlube, sweet talking it and tucking it into bed, but it's always the same! It's under 300km from a full tank to the fuel light coming on.

The best I've ever done was 342km from 53L.
I knew it would be thirsty but this is ridiculous

I'd like to say I'm feeling better after reading that, but, I feel for you brother. My 22re Corona wagon that just went to rust heaven got over 600k's to the same size tank. Ah well, it's the price we pay.

Just discovered mine has a blown head gasket or cracked head or both. Do have a spare head though. I'm hoping changing heads on the 5m-e is as easy to do as the 22re.

Thanks to ivandude for replying too. My computer has been out and have just got it back.


Cheers boys.

[patrickleslie]

Yeah Bitsa, I wouldn't worry about your economy, it sounds fantastic by comparison!! I assume a 5M-E BHG would be pretty straight forward, being SOHC and all. Just check the tightening sequence, IIRC there's a trick to it and it's not just start from the middle and work your way out. And sorry for the thread hijack!

Cheers for the tips Ivandude, I'll have a look into a proper injector service, maybe new injectors even. A nice 7M or JZ is definitely on the cards later on though, that's always been the longterm plan for this car.

[Bitsa]

Patrick. No worries about the hijack. All good.

.... and the air pump makes weird puff noises under heavy acceleration....

Question: What is this air pump you and ivandude talk about ?

Also what spark plugs are in yours ?

Scott. Have sent you a pm.

[patrickleslie]

No idea what spark plugs I have, but I was planning on changing them for new ones when I get back from Melbourne on Tuesday (Going to the Grand Prix ) I'll sus it out and post what I end up buying for it and then we'll both know what we need

I'll post my fuel economy for the trip too.

The air pump is...uhhh...the thing that is on the same belt as the crank and the alternator but is not the alternator or the crank . I think.
There are two large-ish hoses between it and the factory air box if you still have it. It just pumps air around the emissions system and returns it to the air box. You may not even have it in the car, a previous owner might have removed it.

[patrickleslie]

Mt Barker - Horsham 43.30L/399.6km = 10.83L/100km
Horsham - Melbourne 38.07L/353.3km = 10.77L/100km
Melbourne - Nhill 47.36L/427.4km = 11.08L/100km
Nhill - Mt Barker 35.01L/322.1km = 10.86L/100km

Total Trip 163.74L/1502.4km = 10.89L/100km

Average speed was 94km/h according to GPS, so that is all highway driving.

Totally and completely surprised me. I don't see how it can be getting 16,17,18L/100km and then get 11L/100km...Seems to me that it's too much difference to make sense. :s

[Bitsa]

That's more like it. Maybe the 5m-e just doesn't like going slow.

[ivandude]

How granny style are you driving in the city/short trips? Are you avoiding braking hard and avoiding having to go from stop to start?

I spoke with my friend Elliot about his fuel use... He owns a white MA61 (attends the Toyotafest yearly) as I remembered he spent a few thousand dollars on servicing and upgrades to his completely factory mint MA61. Automatic and 5ME of course. I know he had his injectors serviced and many oter things, and also remember him stating he gets about 350km per full tank (50L thereabouts).

Its not everyday someone will spend a good $$ and time to take care of a 5ME So I asked him, did those servicing and lot of money you spend fix the fuel economy? He said no suprisingly!!! But he added that a few months ago he had to change his battery, and since then he's seen over 450km... Moral of the story i figure ... 5ME you just dont know what can happen!

[patrickleslie]

But he added that a few months ago he had to change his battery, and since then he's seen over 450km...

DUDE THAT'S IT!!

As far as I've seen, the 5-ME has TERRIBLE factory groundings and general electricity stuff. If I have my headlights on, radio, and heater, like most drives on the way home from night shift, and I high beam, brake (think the brake lights), flick an indicator on or put down a window or anything else then my digidash flickers and the radio resets! All the driving the Melbourne and back was in hot weather with windows down, no fan because the air con has no gas so we didn't bother, 90% in the day so no lights were on, with only the GPS plugged in and no radio (My GF and I like to talk ). Hence better fuel consumption because more power left in the system for better ignition!

Of course! It's one of the first things I should've check too - fuel, air & spark! Spark as in electricity! If it ain't sparking then it aint burning and therefore it's wasting! It's gotta be that...it isnt anything else. I wonder, sounds like your mate Elliot has just maintained the stock systems until he added a brand new battery. Perhaps I should consider a better battery/alternator/ignition system.

And I drive way Granny spec when i try - shift early, cruise in high gear, easy on the pedals, etc . I only really drive to work and back, all night shifts too, maybe 7km from home at most. It's in Mt Barker so that's a semi rural area which means no stop-start driving, I dont go through any traffic lights, just 3 roundabouts which are always deserted at 1am.

[patrickleslie]

I must get a voltmeter installed so I can prove this theory

[Bitsa]

Moral of the story i figure ... 5ME you just dont know what can happen!

From my short experiences with this motor that just about sums it up.

[ivandude]

Interesting to see if the voltmeter does show any significant drops when different things are in use. I wonder if it could affect fuel economy or possibly chugging down the engine somewhere! I guess they dont call it Electronic Injection for nothing right? In my MZ11 Soarer (running of pretty much same body electronics/systems as the MA61) also does a bit of what you described with power kinda going dim if i turn high beam on, or put the window motor in action. Its not as severe as what you describe though, if your digi dash is on the blink you might have bad grounds/bad contacts somewhere. Moisture can find its way through the firewall (some do rust) and maybe it can get into the dash area?

Water & the weather can definitely make bad contacts throughout an old car. My 82 Soarer has a tail light relay failure box and that also saw moisture ruin it, it needed a minor repair with a solder gun to re-flow a few points, it worked flawless after that. Electronics just have to make sure there is a good signal to go through it should be easy to diagnose.

Haha so now battery, and electronics have now made it onto the agenda for 5ME fuel economy

[patrickleslie]

Haha so now battery, and electronics have now made it onto the agenda for 5ME fuel economy

...and spark plugs too, just to tie it back into the original post.

I know that the water pump exploded at one point with the previous owner so the alternator has been soaked in coolant. Perhaps it just isn't giving enough