Drivability issues

[Dmitry Tolstoy]

Hello people!
the patient is 1997 Daihatsu Applause 1.6L with manual Trans, Injected.
I’ve expirienced drivability issues with my ride ever since I’ve bought it.
Made all the basic tune up, checked for vac leaks, cleaned the TB, changed eng temp sensor (the old one was abused by tap water) changed to antifreeze and bled the air out, zeroed the TPS as should be, changed trans oil (manual trans, quite a loose one).
the car jumps like a horse once I drive it cold, especially pronounced at 1st and 2nd gears, less at 3rd and less so on.
when the car warms up it acts much better although still could give me a jump from time to time at slow speeds. (0-40 KMPH)
The only method I found working to bypass the issue is pushing the gas pedal and try not to absolute leave it. (unless I have to stop ofc 😆 )
The violent jumps are actually happen when I let my leg off the gas pedal, so to counter them I quickly step on again or as I’ve done in past, engage the clutch pedal. (just to clarify – I am an experienced driver)

Idle’s perfect, smooth working engine pretty quite too, revs well.
Going uphill without much struggle, very strong for a stock.
If I push it starting from 2K rpm uphill, it’s pinging until I reach 2.3K +- . (Just for test ofc)
to me it seems like some kind of an Ignition timing issue… since all the jumps accour within that rpm range too.

So after years of trying almost every possible thing..I decided to check whats up inside the ECU.. to me it seems that it’s a bit toasted.
What would you say?

Attachments:

• 20150131_163050.jpg

Topic

[college man]

I can see the small part is burnt. The other components from the picture look ok.
I would say there is a problem there regardless.

[Donald]

The one resistor is burnt. At some point it vented due to overheating. Replace the one on the left of the picture. The others look fine unless you can get a higher res picture to verify.

[Dmitry Tolstoy]

I cannot post here a higher res as far as I tried. but, I can link the pic from my copy cloud.
so here’s the link to the full res and re edited pic, with a download button on top for full quality:
High Res

Mapping:
1,2,3,4) suspected resistors – shape, burnt, color change.
?) Unknown Suspected as damaged – Might be a protective material layer air bubble? (to verify it I should take out the ecu again)

P.S If there’s a way to post a high res pic here, It would be helpful.

[college man]

[quote=”D.Tols” post=148175]I cannot post here a higher res as far as I tried. but, I can link the pic from my copy cloud.
so here’s the link to the full res and re edited pic, with a download button on top for full quality:
High Res

Mapping:
1,2,3,4) suspected resistors – shape, burnt, color change.
?) Unknown Suspected as damaged – Might be a protective material layer air bubble? (to verify it I should take out the ecu again)

P.S If there’s a way to post a high res pic here, It would be helpful.[/quote]

unfortunately the resolution that we have is all we got. 🙁

[Dmitry Tolstoy]

A long one..Sorry.
Today I disassambled the ecu..again.
Inspected closely the parts, and measured resistances. Surprisingly all is within specs, and seems ok. The picture dramatized the look, yes some parts were overheated but they alright.
Well this is what I got until now:

Cold car – Jerks hard around 2k-2.2k RPM, Light throttle. Most pronounced at 1,2 gears. (I guess overly lean)
Warm car – Much better, symptoms almost gone, hardly could be reproduced.

As the focus is on cold, I’m ruling out the o2 sensor as possible cause. (open loop and it’s just 8 months old)
Testing again for vac leaks, could be something I missed. so far I’ve changed most of my vac hoses, the other 3 I left seem in good condition.

I do hear some hissing around the throttle body, cannot pinpoint where..actually it sounds just like an IAC is letting through. I did sprayed water around the intake and the TB gasket injector o rings, nothing changed.
btw, my IAC is built in the TB and has no gasket.
The only thing that I did noitce, is when the car warms up fully, the hissing is almost gone, which is when the car runs better under load.
and..this car dosen’t have any EGR.

p.s I remember that in the past, disconnecting my IAT sensor made the car run better. (engine checked on, probably ran on defaults) – the sensor was checked and tested as good, just in case.

Maybe another clue.. unrelated to vac leak..
In the past, as I chase down the problem i tried to set up the ignition timing with a timing gun via cyl #1. and spot on makrs. (prior disabled the ecu ofc)
But a weird thing happend back then, on under load test drive the car didn’t respond well to a gas, just pinged instead.
so I had to set up the timing by hearing and not by the mark, and it ran much better and pulling good. (advanced it a bit, no scale exist)
Someone said that this could happen because I’m using a 95 octane fuel, instead of 92, which the car was designed for..but I doubt it as a cause. (no 92 around)

So I think, I should stick to chase a vac leak..maybe In another locations or trying crab cleaner instead of water. Is it possible for a leaky power steering pump produce a vac leak? (it has 2 vac hoses)
Any enlightments?

[Author]

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