EP91 Starlet 4EFE Motor - Ignition probs & why won't it stop pinging?

[CILAchainsaw]

OK, so I've had this EP91 for almost a year now. Bought it off a guy who just used it to get to work at Sydney Uni and back, genuinely looked after and only the second owner (as per RTA records), so it hasn't been screwed around with. The first problem I had was that I was having a miss on No1 cylinder. I found this out when I connected my timing light to the No1 ignition lead closest to the spark plug and it only occasionally fired. I then connected it to the No1 lead closest to the dizzy and it fired 100% of the time. Naturally, I assumed the leads were stuffed and replaced them. Nope, still the same problem. I've replaced the spark plugs, cleaned the dizzy cap, reset the timing (with TE1 and E1 bridged, of course) and reset the ECU countless times. I did notice however that occasionally when I went to reset the timing that it was randomly initially out by about 10-15deg either way, which I found quite odd.
Which brings me to my next problem: pinging. This began getting worse in the last couple of months. It happened mostly under certain types of load, especially after getting through bumper-to-bumper traffic in the M5 tunnel and going up the hill. When I went to check the timing I noticed that it was already backed off to 6deg, so in my superior wisdom I decided to put it back "where it should be" to 10deg and reset the ECU. This only made things worse, to the point where if I drove any faster than a blind grandmother and used any more than 1/5 throttle opening it would sound like it was about to send a piston through the bonnet, and generally ran like a dog. After some advice from a friend I tried running it on BP Ultimate, then started using 100 Octane (98 + 10% Ethanol) in it. After resetting the ECU and timing again to stock, it was running OK. As soon as I get halfway through the tank of 100 and fill the remainder up with 95 the pinging returned, although not nearly as bad or prevalent.
Could the two problems be related? Does this mean I have problems with the dizzy or computer? Coz that's the only thing I can think of. I've also had suggested to me a dose of Subaru Upper Cylinder Cleaner, but I don't imagine it would really need it as it has only done about 170,000 (mostly) easy km's. Any help appreciated, as always

[DaveSpec]

I i've had both of these problems before except with a simple carby engine so it was a whole lot easier to fix
To the point, I've had problems with cylinders not firing on every usually due to incorrect mixture. This maybe harder to diagnose however with an ECU. The easiest way to check i found though is:
Depending on what types of leads you have you want to try and expose the metal the clips onto the spark plug.
then start the engine
pull the lead off the plug and move it close to the cylinder wall, the spark should be able to jump 1-3cm from the top of the lead to the cylinder wall. if it fires everytime then its not a problem with the dizzy/lead.
should also note: WARNING be careful where you grab the lead because the spark can jump through the insulation of the wire and earth through you. I've had this happen on at least 2 occasions so its probably wise to grab it with insulted pliers or something.

The pinging could be due to an incorrect mixture too, (too lean), or the engine running hotter than usual which if its gettin worse could be from an increasing carbon build up in the combustion chamber. I'd probably be looking at mixture first as that seems to be the most likely.
However this is for carby engine i haven't played with too many EFI systems.
The computer does sound a bit over the place though, best thing to do would be to monitor it whilst driving but im not familiar with these ECU's so dunno if they have a simple output or you would need a shop set up to check

[CILAchainsaw]

Ye I also checked the thermofan to make sure it wasn't overheating, but it was fine, and the temp gauge always hangs around the halfway mark anyway.
Sounds like it'll defs be worth hooking up a multimeter to the oxygen sensor output and (carefully) watching it while I drive to see what happens.
Does anyone have the ECU pinouts for this motor?

[4th surf]

I've just had the same problem with the 1UZ in the Surf with pinging at midrange under load and the type of fuel really didn't matter, didn't do it cold but only at operating temp . Now the engine is in good order and did fairly recently get the "Suby spray" down it with no difference, she also got new O2s, leads plugs and coils. On a side note I also had what presented as tappet noise which while annoying being a mechanic I just quite simply couldn't be bothered doing anything about it. Even with the scanner plugged in everything presented "in spec"

Now a few weeks ago I threw the full time mechanics in and moved into a teaching position at the local trades college, a week and a half ago during an afternoon with no students I was tasked with getting the injector test bench going as it had not been used for bloody ages. So while trying to find some injectors to run thru the "process" I thought "Bugger it" and rolled the Surf in and pulled the injectors from the UZ that resides under the lid. Ran them thru the process, back in and went home. Well what do you know? No more pinging and the "Tappet noise" is gone. Performance is up and fuel consumption has improved.

So from what I've just dealt with I would say that Dave has hit the nail right on the head with his comments about mixture being lean. In your case I'd begin with a new fuel filter and over the course of two tanks of fuel run two bottles of a good quality injector cleaner thru each tank and see what happens. If that fixes it then all well and good but you really should pull the injectors out and get them serviced as they do gum up. As for the ECU if you are or have a mate who's good with electronics it'd pay to pull it apart and not only replace all of the capacitors but give the tracks a good clean up as well. Should be like a new car after that and if memory serves correct the EP91 is quite a lively performer

[mattysshop]

agree with lean possibility - 4afe ae93 with 32X XXXkm's... ALWAYS used to ping regardless of timing (8 BTDC) and fuel (98 RON)...

fuel filter change little better... not much... was going to just buy some new injectors (there about $25 ea from the USA)

but thought i would try the fuel pump first (just a cheap fuel meiser/denso aftermarket)..

not only does it start alot easier seemingly instant when you hit the starter motor, vs what i had accepted to just be normal of 3 sec of cranking before firing..

car has a little more instant power? if that makes sense? not really any more peak power..
so yeh i'm probly going to throw a set of injectors in it also for good measure, but i'm very impressed with this so far..

[CILAchainsaw]

Funny that, I was actually beginning to think along the lines of injectors too. I've already run a few tanks of 100 octane through it though, so I imagine it should be clean by now. Again, does anyone know where to get the pinouts of the ECU so I can splice a wire in to monitor the oxygen sensor output?
Being an ex appliance tech I'm pretty good with electronics, so I might take a trip down to Jaycar and get myself some circuit board cleaner and some new capacitors to solder in while I'm at it. Maybe this could explain the weak ignition too, computer sending too weak a signal for No1 to fire properly? Worth a shot I suppose. Any other suggestions for the ignition issues?

[DaveSpec]

well that was surprisingly easy...
http://dub-se7en.toyotagtturbo.com/u...o/ECU_PINOUTS/
it has the data sheet for the 43f3 ECU, hope its the right one

[DaveSpec]

actually this whole page might be helpful

http://www.toyotagtturbo.com/forums/...to-ECU-pin-out

[TERRA Operative]

You can also use the diagnostic connector. Ox is the pin that accesses the oxygen sensor directly. Connect your oxygen sensor tester thingo between Ox and E1.


How are the capacitors in your ECU? If they are leaking or dried out (they 99% will be if they are original) that can cause all sorts of problems.

Also, go get a paint pen and draw a line on your crank pulley, making sure it goes across the ridge where the rubber damper ring is. After driving for a while, if the lines no longer match up you have a stuffed harmonic balancer, which will explain the timing issues.

[CILAchainsaw]

Checked the harmonic balancer, all good. Put 2 strong doses of injector cleaner through it, no difference. It seems to be ECU related, because whenever I reset it I always get a much higher idle speed for a while and the pinging mostly stops, but after a few days it goes straight back to pinging again. I'm also suspecting the fuel pump, as I bent down behind the car one day and noticed that it was running intermittently and not steady. Connected a multimeter to the fuel pump pin of the diagnosis connector to check that the computer was supplying constant power to the pump, no issues there. Does this mean the pump's stuffed? Apart from dropping a lit match into the tank, what else should I try? I'm at a loss here...

[TERRA Operative]

Can you get your hands on another pump to try?


You could also try unbolting the fuel line where it attaches to the fuel rail and point it in a decent sized bucket. Get a mate to turn the engine to 'on' (but don't start it) and see what the flow is like.

[CILAchainsaw]

Would any in-tank pump from any small Jap 4cyl fit the same? We don't have any Starlets at my wrecking yard but we do have plenty of late model 323's etc...
Still getting around to being bothered to replace the filter I ordered off Ebay (~$30 from Britian as apposed to $79.99 in Stupidcheap Auto), and putting the fuel line into a bucket while I'm at it...
Again, is it just the electrolytic capacitors that need replacing?

[TERRA Operative]

Yeah. Just the electrolytic caps, and repairing any damage or corrosion they may have caused (a matter of luck if yours needs extra attention or not).
I can supply a set of caps, or do the swap for you for a modest fee if you like.

[CILAchainsaw]

All good mate, a trip down to Jaycar got me all the caps I needed, although they didn't have any 15uF or 33uF caps in 35V's for the computer in my 20V which I wanted to do while I was at it. Do they really need to be 35V rated though? I don't imagine there would be any need to up the voltage that much in what is essentially a logic computer, wouldn't 16V caps work fine?
Also got my hands on a AE112 fuel pump assy, so I'll swap the pump over if it will fit and save the low fuel warning sensor for the 20V which failed a long time ago (it seems they have a habit of doing that). As soon as I get a spare weekend I'll change the pump and filter over and see how it goes...

[CILAchainsaw]

Oh, and Davespec: thanks, but I actually did Google for the ECU pinouts first and the ones you posted here are the first ones I found. The reason I didn't use them and asked for them on here: the turbo and non-turbo ECU's are actually different