1Sahar 3S-GTE running rich mixture?!

[EDDYSW20]

The defect and its symptom are:

1. Idle with black smoke.
2. Engine jerk when idling.
3. spark plug goes black and after replacement its ok for a while but later will be like running on 3 cyl.
4. Changed plug , running good for a while but the prob comes back.
5. Adjusted Mass Air Flow sensor, defect persists.
6. Problem happened after 6 weeks in the paintshop.
7. Horsy seems to come back everytime you findle with the engine (adjust MAF sensor, change plugs, etc)

This posting was raised by 1Sahar. Lets try help him resolve this issue before he starts changing an engine or do something fishy like adjusting sensors....

Some question,

1. What type of painting did you do? Only external touch up? Did you get the engine bay painted? Did you get the wirings or interior findled with?

2. The idle issue only raises during startup or right until warmup and running around for awhile? Does the defect persist after warm up?

3. Does black smoke persist throughout the engine running period or does it end once the engine is fully warmed up?

4. What fuel are you using? Have you tried the Shell V power? Is it the same? Whats your fuel consumption like?

5. What checks have you done so far, other than findling with the engine? Example would be, have you checked compression? Have you ensured there is no bubble in the coolant? Have you made sure the timing is correct? Have you checked for any diagnostic fault codes? Have you confirmed distributor arm and contacts are not oxidized?

6. How long did you have the car before sending it to the paint shop? Are you sure this occured after the paintshop visit?

7. If you're willing to drive to Nilai, we can meet up with my super mechanic, an aircraft engineer, excellent at diagnostics!! Hahahaha.....

 

[1sahar]

hi eddy thanks for creating new post for me, ur good guy

---------- Post added at 11:28 AM ---------- 6 hour anti-bump limit - Previous post was at 11:23 AM ----------

reply to your question.
1. type of painting = whole body and the painter did not mess around with my wirings and engine compartment.
2. the idle issue happened all the time ( at that time )
3. black smoke came out all the time, but not too much.
4. im using 97 ron
5. i have checked compression and timing. and everything is great.
6. been having the car for 5 years, but only about 1 year after i changed to this engine ( previous sudah jahanam).it happened before and after i changed to new plug, its ok.why does the plug wet with fuel after a week being left unstarted.
7. im adding emanage ultimate so i may replace the use of air flow to map sensor and retune for better fuel consumption.( current is high)

 

[EDDYSW20]

Hahaha, thanks for your compliments....

So, you reckon you'll solve the defect with an E-manage? You hope so. I'd rather know whats wrong first before Emanage tries to keep it under blankets.....

Have you noted lost of engine oil?

Theres one statement that sounds off the charts..... plug is wet after a week? That aint fuel. Fuel does not 'stay wet' for that long, unless you're running a diesel engine. You've either got your fuel tank filled with crap, or you're having engine oil sipping into the combustion chambers. But then you're not smoking white, not burning oil, so, that overrules engine oil. Maybe, someone poured diesel into your tank!! But if thats the case, your engine should have exploded some time back..... Perhaps then, someone shoved in 2T into the tank or some stupid-brandless-useless-piece-of-garbage additive which is supposed to enhance the engine performance, instead, coagulates the fuel in the tank when left too long. Ok, so, back to square one..... crap in the tank.....

Conclusion for the time being, I'd say something died in your fuel tank when you sent the car for painting! A rat, a mouse, Don't know how, but if that's the case, Emanage will have the same result. Ok, so, I am scaring you a little.... hahaha..... thats doesn't sound simple, a simple solution would be...... hemmm..... painter mistakenly started the engine during painting and painted the air filter, clogged the throttle and autochoke..... and screwed the tuning by inhibiting air into the chamber...... hence a rich mixture.... ok, that sounds much more simpler...... hahahaha

Either way, your fuel consumption will be bad, due contamination of the fuel, resulting in uneven combustion of the fuel.....

So, another question, what did you mean "(at that time)" ? Have you solved this problem? Sahar, cer criter cer criter (Clip from HaNtU kAk LiMaH bAlIk KaMpUnG).....

Brgds,

 

[1sahar]

hi eddy,
thanks for the informative replies and mostly your time.
What i meant by that time was ,yes the plug is wet and smells petrol. its like when cranking the plug wont spark., so its flooding the combustion chamber. after plug cleaning the engine starts beautifully.This happens after a week or so if i didnt start the engine.so what i think is maybe the air flow is giving a rich reading.so when idling its drinking the fuel like thirsty hyppo.

i have checked the timing and its good.so two things came out that i think might be the cause of the problem.
1. the air flow.
2. the o2 sensor.

so maybe if i add emanage, i could tune the fueling on idling for a better consumption maybe afr 14.7 on idling and set afr 11-12 when boosting i could get better consumption, maybe.....

 

[EDDYSW20]

Sahar, remove the air filter and try running without filter for awhile..... your filter could be too restrictive..... or your fuel pressure enormously high, upgraded fuel pump does have this impact if your regulator is about to 'jalan'.... hahahaha..... oxy sensor is another cause but as simple as it is, it aint cheap.... perhaps I could help you with that... RM100.... mau tak? hahahaha if your MR2 is up to short drives only, then you may want to look at your cold start injector.... it could be working 'overtime'.....

all the best, and keep us updated..... it sure isn't normal to have that kinda operations.....