Poor engine performance under load

[cramp]

Hi everyone!

Warning I'm a total car noob, I've only had my 2nd hand car since april of 2012, and it was in pretty bad shape when I got it.

Background:
1. 1997 Kia Sportage
2. newly changed oil, oil filter and atf (twice)
3. new spark plugs, high tension wires
4. had a compression test and low compression on valve #3 (compared to the other 3)
5. Fuel: Caltex Silver Gasoline
6. Transmission shifts fine up to 4th gear
7. newly cleaned throttle body

Symptoms:
1. Car is noticeably slower with A/C is turned on and with passengers, as in it takes 10-15 seconds before it accelerates above 40 km/h.
2. Intermittent "pop" sound coming from exhaust.
3. Medyo rough idle (around 750 rpm, 1000-1200 with AC on)

Description:

Starting the car is no problem, one click lang sya mag start. pero minsan pag naka reverse sya it would stumble and then stall, but not all the time. Under load with one passenger, the car suddenly loses most of its power, noticeable when accelerating on a high way from a stop. The speed would go to 20kmh with the gas pedal depressed half way to full (RPM stays on 2000 for a while), it shifts fine naman eventually pero it just takes a long time to go to around 60 (15-20 seconds).

The car runs a bit better without any load (a/c off, no passengers) pero hirap parin up hill, goes only about 20 kmh. Shifts fine and runs quite peppy on non-inclined roads.

Dilemma:
I've had my transmission checked, according to the mechanic it shifts fine naman daw. Ang tingin ko it's the engine itseft ang may problem, kasi without the a/c ok naman andar nya eh even after a cold start. Plus nung sinabi sakin na mababa yung compression results nung valve 3 dun ko na naisip na baka nga engine. I started to think about getting an Engine top overhaul, but not sure if this would be fix the problem. Also, after reading a bit more about the problem, I'm starting to believe na baka it could be other things in the fuel system. Maybe a fuel injector or fuel pump that gone bad. Baka its running poorly as it is, hindi lang masyado noticeable pag walang load yung car.

Question:
What's the first thing to do when I visit my mechanic? I'm avoiding to be bombarded with his theories, and wanted to minimize the "guessing" replacement parts. And of course, would not want to spend so much right away. Should I commit to the engine and go for a top overhaul? Or should I get my fuel pump/injectectors/filter checked? Ano po sa palagay nyo?

Sorry for the long post, I've been trying to fix this problem for weeks and I obviously am desperate.

[batangtalyer]

sir cramp, major tune up lang ang katapat nyan.

[cramp]

sir cramp, major tune up lang ang katapat nyan.

Salamat sa tip sir batangtalyer! What's a reliable place to get one? Thanks again for the response!

[batangtalyer]

ndi ako makakapag recomend sayo kase maraming magagaling talaga. pero eto yung procedure na kadalasan ginagawa namin jan.
basic mechanical condition vs. manufacturers specification. data scanning, code reading and sensor or circuit integrity test. tapos yung gas analysis ( emission output.) yan yung basic data na kinukuha namin bago kami mag start ng tuning. sa mga shop na may engine analyzer alam po nila yan sir. sa usok pa lang nalalaman na kung ano ang posible na problema nyan.

[cramp]

do u know the compression per cylinder? baka off ka lang sa timing

I can't recall the exact numbers eh, pero If memory serves me correctly it's around 160+ more or less on cylinder 3. 1,2 and 4 were the same around 190.

ndi ako makakapag recomend sayo kase maraming magagaling talaga. pero eto yung procedure na kadalasan ginagawa namin jan.
basic mechanical condition vs. manufacturers specification. data scanning, code reading and sensor or circuit integrity test. tapos yung gas analysis ( emission output.) yan yung basic data na kinukuha namin bago kami mag start ng tuning. sa mga shop na may engine analyzer alam po nila yan sir. sa usok pa lang nalalaman na kung ano ang posible na problema nyan.

Eto po ba yung major tune up?

[ahlecks]

*batangtalyer

sir may shop po b kayo na gumgawa ng mga engine analysis as you mentioned? plans to have my 96vti diagnosed coz my tyme n hesitant cya sa acceleration, parang pigil ang takbo, bago nmn sparkplug ko. tnx

[cramp]

UPDATE!

Ok so here's the short version.

Went to KIA Pasig and all they said was it was my transmission and charged me 75k for it. They didn't even check the engine. Forget that, so I went to my trusted mechanic and did the following.

Repairs:
-Engine overhauled due to water seeping in cylinder 3.
-Changed spark plugs and ignition wires
-Changed Oil and oil filter
-Changed gas pump and filter
-changed the TPS
-cleaned/flushed the radiator

Results:
-Car got a bit of HP back while under heavy load, but still not even 70% of it.
-Car runs now even better with ac off, lakas ng hatak.
-Engine is whisper quiet
-AC now colder

New symptoms:
-Idles roughly and surges and stalls when engine is cold
-Sometimes while running, I can feel the steering wheel and brakes become stiff as though its about to stall.
-Wiper stops sometimes while on low.
-Lights in instrument panel gets dim when I turn on the headlights (80/100w)
-Exhaust smells somewhat like raw gas

Best guess:

I also brought the car to a battery store, they checked my charging rate and it's about 13.8-14volts when idle, and about 12.8v when under heavy load (AC, headlights and radio). Under powered alternator or bad battery? I don't have problems starting the car even after 2-3 days of not using it. But it sometimes stalls while running. especially when it surges right before I stop.

I feel that with the engine running great, it now shows problems with my electrical system. I feel that my alternator and battery might be on its way out. And with that it might not be supplying enough current to the computer box, making it go crazy causing the surging and stalling. Would that make any sense?

Question:
-Would changing the alternator (upgrading it to 90amp from 60amp) and battery be a good next step?
-Anything I should look out for should I have my alternator changed?
-Any recommended shops where to get one and to have it installed?

[cramp]

sir cramp, major tune up lang ang katapat nyan.

Sorry if ang noob ng questions hehe. My 1st car din kasi.

What's a reliable place to get one?

Thanks for the response!

[SiRbossR]

^SpeedyFix, PTT Service, or any Servitek Branches.

[onemph05]

Get the compression issue fixed and see if the catalytic converter has been replaced.

[kinyo]

check timing advance mechanisn ... this is not routinely checked during regular tune-up

[sirkosero]

do u know the compression per cylinder? baka off ka lang sa timing

[sirkosero]

imho, no need to do overhaul yet. unless there is oil in the plugs. for the most part, id follow batang talyer's advice. also, the timing

btw, id also check the aircon compressor. mukhang naninikit

[cramp]

imho, no need to do overhaul yet. unless there is oil in the plugs. for the most part, id follow batang talyer's advice. also, the timing

btw, id also check the aircon compressor. mukhang naninikit

Thank you for the advice sir.

Just to add more to the a/c compressor theory. I actually just had my ac condenser replaced due to leaks. After the repairs bumalik na yung lamig to full blast, pero dito ko lalong napansin yung bagal nya.

While I drove home from the a/c guys, dun lalo naging obvious yung bagal nya with the ac on. On a/c #4, grabe mga 20-30 kmh lang takbo ko with the gas pedal 3/4 all the way in. Super tagal before it starts to rev up passed 2000 rpm. I'm thinking hindi kaya there's something wrong with the compressor kaya hirap yung engine ko patakbuhin sya? Pero in fairness malamig sya kahit lunch time!

[sirkosero]

ah... yun pala. possible overcharged yan or kulang ng oil sa compressor.

[cramp]

ah... yun pala. possible overcharged yan or kulang ng oil sa compressor.

I'll pay close attention to it more. Pero so far hindi naman noisy yung compressor and efficient naman ang cooling nya. The ac people said that they already added compressor oil kaya we can rule that out I guess.

Pero so far ang biggest hinala ko is baka nga timing and baradong air and fuel filter. I'll probably bring it to Migs for a major tune up and go from there.

Will keep you guys updated soon. Thanks again sa responses.

[cramp]

Bah.. A new symptom guys.

I've started to notice that the car now is beginning to have problems with cold starts. These last two mornings, when I tried to start the engine by turning the key, I get no response.

If would hold the key in the start position after 5-7 seconds, eventually the engine will crank and the car will start fine. Does this mean I have low fuel pressure?

[sirkosero]

have your battery checked. thats a sign of a battery nearing its end of life

[cramp]

have your battery checked. thats a sign of a battery nearing its end of life

Thanks sir, I appreciate the info.

[cramp]

Just an update.

Fuel filter and air cleaner has been replaced, unfortunately no noticeable difference. I did notice that if I'm parked on a leveled street I have less cold starting issues. This leads me to the idea that I might have a problem with the fuel pump due to the falling fuel pressure. Does that make any sense? If I'm parked on an incline (front raised), I almost always have problems starting cold.