legacy200425

So thanks everyone for help. I finally solved the mystery.

The issues with "hesitation" was a god damm valve cover gasket

I noticed that drivers side was leaking quite a bit.. So i decided to change that gasket but when i removed both covers i also checked valve clearence which was bad.. so i did the valve adjustment then replaced the gasket on drivers side. When i put that back together it was a brand new car for a week or so.. then the hesitation was back. So i also did the passenger's side and and hesitation is gone and its all fine now.

The second problem was just my stupidity, it was cuz of bad battery.. when i got the car i checked the battery and it seemed fine.. it had like 12.4V i think and the starter was rotating fine i thought.. but i tried to measure the battery while starting and voltage has significally dropped with different battery there wasnt such a huge drop in voltage and car started right up even in very colt temperature.

Perhabs this will help to someone..

It does sound fuel related, I would not continue to through parts and guesses at it... measure the fuel pressure. Tee in a test gauge between the fuel damper and the connection at the manifold. I have run the hose out the back of the hood and held the gauge face down to the windshield with the wiper, so I could see it as I drive. If the pressure is good you can rule out pump and filter issues.

Hello, today i tried to check the fuel pressure like u said and it seems all fine its within the range. no drops or something like that.

I kinda forgot to mention that in that car there's also and LPG, the problem is that the LPG is not working atm. Service told me that all 4 injectors are bad and needs to be replaced + reducer. I didnt mention the lpg because i didnt think it would be somehow related to this issues.. Since it should run fine when the lpg is turned off right ?

It does sound fuel related, I would not continue to through parts and guesses at it... measure the fuel pressure. Tee in a test gauge between the fuel damper and the connection at the manifold. I have run the hose out the back of the hood and held the gauge face down to the windshield with the wiper, so I could see it as I drive. If the pressure is good you can rule out pump and filter issues.

Hi, damn awesome idea. I'll try to get the fuel pressure gauge and check that out.

That long cold start time makes me think it's fueling. Either sock filter needs to be replaced, or pump harness connectors need to be cleaned, or both.

 

 

 

Probably easier to check the harness connector. Make sure the connector pins are clean and tight. IIRC there was someone here recently with similar fueling issue on GT, ended up being the connector.

When i replaced the pump i tried to clean that sock with air and brake cleaner. I guess i can try to remove the sock and see what happens

As far as the plugs you are spot on with the Platinum so that’s correct so I would not change that. As far as your fuel filter/pump I was thinking after I posted my prior response that could be the issue. I believe that part is a complete assembly only and I would just change out the entire part and not try to fiddle with just a certain component of the part. I had to change out a fuel pump a few years back in my daily Honda and I was thinking to myself the whole time I just paid $300 bucks for an entire assembly when I could have changed the filter for $20 bucks or less if the part was not integrated into the assembly. But then again any car Imhave had from 2006 and onward fuel filters are a whole assembly. Just another money grab from the manufacturer but nothing you can do about it. Personally I would not deal with aftermarket pumps and just pay the dealer what they want for the part.

 

Also thinking of something. Did you buy the plugs from a reputable shop? A lot of fake NGK and Denso plugs are being sold online that could produce an issue. Just an afterthought.

Well thank you for your response. The problem is that if it wont be the pump then i spend fortune on that without fixing anything. Those NGK are straight from subaru.

Ya this sounds like an exaggerated version of the "stumble" people get when upgrading , and or removing the damper from the fuel system in the procces.....do these dampers ever fail...kinked or damaged fuel line under the manifold

 

Literally no worthwhile experience specific to this car but sure seems fuel related

 

Sent from my Pixel 3a using Tapatalk

Hi, well i try checking that out. I guess there isn't possibility to clean that damper if its clogged or something right ?

Now here’s the question. What kind of plugs did you use? The fourth Gens hate Iridium plugs so that could be the culprit. Every time I change out my plugs someone always to be in the store complaining about their fourth gen GT or other model running like crap after they sold them iridium plugs.

 

Or the other culprit is the injectors. But those generally will throw a code of something is an issue.

 

By chance where do you live? Could be running like crap because of the winter blend fuel. An easy fix would be grab some Techron concentrate for six bucks and go fill up with ethanol free and see if you still have the same issue.

 

And another idea and just taking a shot in the dark. Who changed the oil last? You or some shop? It could be overfilled and that could be a factor. I know when I was a newb I overfilled my car by a quart or so and it did exactly what you were describing. Also any change in oil brand or quality(Like going to high mileage) sometimes does this. I am very I tune to how oil effects all my cars and Mobil 1 regular seems to be the best. The more you go up in the chain of oil the more robust the add pack is and can bog down the engine and make it feel like you have an issue. In fact to be honest last oil change I switched to Castro’s Edge EP and my daily Honda Civic did EXACTLY what you car is doing. Switched it back to M1 and no issues at all.

 

Just throwing ideas that may help since the point is to get the car working quickly.

Edit/Delete Message Report Post Send a private message to legacy200425 Find all posts by legacy200425 Reply With Quote Multi-Quote This Message Quick reply to this message

Hi,

i'm using NGK-PFR5B-11 those sparks are brand new. I dont think the problem is in gasoline, my friend has a 2.0 121kw 2006 and runs fine and we tank on the same gas station. I live in Czech Republic.

About the injectors i'm going to try liqui moly gasoline engine cleaner maybe it'll do something.

Oil has been changed recently by me, but i think its not overfilled (i still check that out) engine did the same thing before with old oil even when low on oil..

I tried to change the fuel pump just the pump not the whole assembly and that "filter sock" i guess i can try to remove that sock if it gets better or not. But if it would be fuel pump it would have bigger problems when driving or at higher rpms it would work or not ? Because once u take off it runs all fine.. You can cruise slightly above idle and no shaking or something like that..

possibly throttle body issues--possibly carbon build up on plate--or drive by wire or compression

 

what software is that and how are you connected

Hi, it's drive by wire. Throttle body has been cleaned, gasket is quite old so im waiting for new but i dont think there will be difference. I'm using Free SSM

I also tried different crank sensor and no difference.. The problem is that if u build up rpms slowly its good.. but if u tap gas pedal fast there's a 1-2sec where it "chokes" then rpms go up.. I also guess

long cold starts has something to do with this. I tried switching the key few times to build up pressure for the start but no difference. Once its warmed up starts all fine.

Hello guys,

could someone help me with following issues ? When i try to start the car early in the morning in cold weather it takes like 10-15 sec, once its warmed it starts without problem. There's also a big flat spot when i try to smash gas pedal or when i try to accelerate from a stop. I've replaced maf sensor, cleaned map, new fuel pump, new spark plugs, previous owner replaced coil pack.

Please does anyone have any idea what to look for ? Because atm i'm kinda desperate.

adding link to video + live data

If it's both of them, I would check the wiring diagrams to see if there is a common connection/fuse that feeds both rears. It's possible that both actuators are out, but I would try to rule out common wiring first.

Thank you for advice.. I just couldn't find a useful wiring diagram for MK IV to check that out. All fuses checked and none of them bad. I guess I'll try to check hinges if wires are in good condition.

actuators are the culprits.

Well thank you for your help.. I'll check that out. I thought it's too much coincidence that both doors wont lock/unlock. You think that both would gone bad at the same time ?

I just bought that car recently.. and previous owner told me that back doors never worked. So i thought that it's just a fuse/relay or coding problem..

Hello,

does anyone had an issue when central locking system wouldn't unlock back doors ?

I have 2 keys.. when i use remote control, it unlocks both front doors and trunk but won't unlock back doors. Same if i use arm rest control for unlocking, it opens only front and trunk

Any ideas what could it be ?

Thanks for any response..