Early EDM non-cat 4A-GE 16v Bluetop Fails emissions (high co)

[The Doctor]

sounds like you need to find where the midgets hide, with their buckets of fuel

[ray]

I got the Same f*"* problemen! And Nothing helps car is almost More then a year from the road

[Bean]

I got a feeling you got some internal leaks (oil, water or both).
I only failed emission once and that was with a 1cm hole in the exhaust when the hanger ripped off. Back then I had to test the car once a year due to regulations of non-CAT cars

[ray]

My engine is complete rebuild everthing is New! Maby my Green temp sensor on de Back is the problem

[Rascal21]

I found the problem and it`s not ECU or internally exploding engine of doom

ECU has a body-harness plug, on it goes the plug with wires that goes from Ignition to 2 pins, battery to 1 pin etc etc from the body-harness, which we know already.

Since this is a TA40 Carina, that body harness is omitted and new wires with small cable shoes installed instead for the essentials (Minus COR, Fuel Pump Relay, Fail Safe Relay and EFI Relay).

Theres a pin on that plug that`s called VAF and it`s supposed to tie in with Cold Start Idle-Up Computer (The smaller black box) and then eventually go to the CO Variable Resistor (The potmeter for A/F mixture).

I installed a wire with a small Wurth female connector on the VAF pin on the ECU and cable shoed at VAF wire (Black with Red stripe) on Potmeter, voilà!

In short, wire between VAF pin at ECU (Pin # and to the Black-Red wire (the lone one in the plug) at Potmeter.

   

Which actually means a lot of people with Early EDM 4AGE swaps into KE70`s etc are failing emissions because they couldnt figure this out

Ray, if your car has a swapped Early EDM 4A-GE then this is likely your problem also
But if you have an Early EDM AE86 and the car just has bad CO values (Way less or more than 1.0 Lambda) at your local emissions/inspections center, adjust the potmeter while they have the emissions counter stuck in the tailpipe, until you get the correct value (Somewhere around 1.0 Lambda and anywhere between but not outside of 1.0-2.0% CO)
If it`s a lot of CO but way more Lambda and adjusting Potmeter does a bit for your emissions but still not getting close, you probably have an exhaust leak.
Knowing exactly what car and engine+ECU you have could EASILY help identify your problem though, I can`t find your project thread anywhere so it`s a hard nut to crack under present circumstances!

Now I have another problem, adjusting TPS, because I discovered that the throttle quadrant set-screw (the one you put feeler blades in at closed throttle to adjust TPS) is missing (must have shaked itself loose) and needs replacement.

The problem is, I can`t find anywhere in the FSM how much that set-screw is supposed to go, so I`m assuming put 0.47mm (0.45mm) feeler blades between and put in the new screw until I start feeling some resistance + a little more.
Meanwhile I have a lumpy and high idle (even with CO potmeter adjusted all the way down), maybe because of the other set of injectors that I installed.

That said, I think with the TPS adjusted, the car should sail through emissions with no problem, will update on that

[Bean]

10 points to totta then

[totta Crolla]

Thanks Bean ! lol
Something awry here though, all through this thread th op states that the TPS has been set but now he finds this out. The TPS has a great bearing on how the engine runs both at idle and driving. The whole point of pressing the throttle whilst in diagnostic mode is to check that the TPS is going off of its idle setting, should see normal code (approx 1 flash per second) and code 11 with pedal pressed.

[Rascal21]

Indeed 10 points for this guess to Totta!
As I said I`m here to learn, I know only a little about 4A-GE`s and forums are usually the way to go!
The Cold Start harness is part of the Body harness on AE86, which a TA40, KE70, TA60 etc usually does not have (unless its a 2T-GE/3T-GE/3T-E/4K-E/3K-E/7K-E or something)
Kind of odd that people have not had this problem before though, but I guess they get their cars (KE70/TA60 or whatever) approved and tested pre-swap, then go ahead and swap the engine and drive around and slam it for 2 years then sell car+parts and never have to cope with emissions test.
But I`m stubborn and think doing the swap and having it semi-legal and sticking with the car is better and more fun

ALSO 10 points for the man who linking to the Ross guide, it shows a lot of interesting information about what makes the 4A-GE ECU`s "tick"

And to be fair to everyone who chalked it up to internal engine problem, normally I would have also chalked it at "borked engine".
No secret the engine IS old and the emissions issue could very well have been that as well, on top of that most of us have seen or heard 4A-GE`s not pass emissions because of leaky piston rings, valve seals, damaged HG etc which for example is a common problem on 4A-GE`s that have been through a overheat or two.
That said, the symptoms are usually a combination of high CO emissions, serious compression problems and they don`t have lambda values off the chart.

The TPS is a long story that I felt was not necessary to tell here, and as usual we can surmise that leaving out info about what you`ve tried to solve the problem, in technical threads like these, IS a bad idea, about to correct that however..
I DID adjust TPS to the correct values a year ago (a mere 1 or 2mm deviance from where the TPS was sitting), but THEN a few days ago found that it resulted in engine revs racing when you try and hold the throttle at any rpm`s between 2000-2600 in idle condition, but in hindsight that probably would have been because of the missing potmeter, the injectors that I swapped in, and the pig rich a/f mixture.
The TPS and Throttle Body had scrape marks across them which both I and the inspection mechanic assumed to be a position worth trying out barring anything else (This was just before I sat down and finally figured out the VAF>A/F potmeter wire), and the TPS was misplaced according to those scrape marks, so we both figured the TPS could be adjusted to that position to see if that helped with the 2000-2500rpm racing AND emissions both at the same time, it did help with the racing but did ZERO (one way or the other) for the emissions when potmeter was not connected to ECU.
Now that the potmeter IS working, it`s back to getting things back to exactly how they were before I swapped it out/fiddled with it etc

As usual, will update with results.
As far as emissions go (engine is probably due for a little freshening up anyway), if I can get it below 4,5% CO and 1.0 Lambda it`s good enough to do what I need to do with the car for this summer (transport some parts and shit)

[Rascal21]

Finally passed, I adjusted the VAFR (Variable Air Fuel Resistor) until I had lowest RPM, which was rough (So I knew it was running lean), which at the inspection gave me 0.2% CO (Compared to skyhigh 8%....) and 1.8 lambda on the emissions tester, then I adjusted it to 1.0 Lambda (ZERO rpm deviation at idle), and landed at around 1.7% CO.
FSM specifies 1.5% CO +-0.5%, in other words it`s well within spec, and that concludes this little adventure and topic (and made me a little wiser).

Now I`ve worked so much on 4A-GE`s that I don`t know how to put 5+5 together anymore, and still have another 2 projects to finish (Rusty AE86, Not so rusty AE86, each with their own challenges), so we`ll see how that pans out throughout the summer!

Have to underline again, thanks everyone for all chime-ins, Totta`s nail-shot made me take another look at ECU pin-outs to see if I was missing something (Can never be too sure, can never learn too much) and that`s exactly where the problem was!

Anyone swapping early EDM 4A-GE`s with 12060 ECU`s need that potmeter+wire from VAF pin on ECU to VAF wire on Potmeter (Black with Red Stripe)

Wish Ray would update about his problem too, kind of interesting if he owns an AE86 and still cant get CO% down..
But other than that I consider the topic closed!

[banpei]

In principle classic cars in the Netherlands are allowed to pass emissions at 2.5%. So as long as Ray gets it below that he should pass.