Hi guys 

As the title my pickup seems to missfire when proceeding with low load on the throttle pedal. The case is like when driving , for example, 60km/h and you find in front of you another veicle going at 50 km/h : so  you have to leave the throttle pedal for a moment and came back steady to procede at 50. So it starts to pull back and forth. If you load more it goes well . On load or heavy load seems to run fine, it doesnt smoke. I do 25km/L. 

The pick up has 15500km , timing belt (as write on it from the last owner) at 89000.

I already change the fuel filter (as well the air filter)and the rubber hoses coming back from the injectors. This last because seems that the 2 injectors( in the "center of the car" side) seems to leak. 

Water thermostat on my way to be change because water temp stay low (around 70° but in this crazy hot days stay up) but the fan work and it doesn't rise above 95° i think.  Classic hot start problems(ordered a new temp sender too)but nothing other than that hahhaah 

Where i have to look at?

Many thanks

 

Hi Zimo

There is something I need to clarify. Does the engine run well at idle and it bogs down only in the intermediate phase from idle to low load?

Please tell us also how the issue started to happen. I think you drove the car a lot without any problem. Was it a gradual process or a sudden one?

For now my advice is to bring the cooling system to its normal operation. Forget about how hot is now and a thermostat in good order doesn't matter. Solve the fuel leaks at the center of the engine.

Last question: can you test the engine computer for any stored errors  and live indications? Particularly interested in coolant temp. sender working well.

 

Thanks for the reply

Yes at idle seems to be fine. The problem came out while driving on the street not when taking off from stop.

I own and drive this pickup for around 2000km in which i refill the thank 3 times . The problem seems to came out after the second refill and i than changed the fuel filter but seems that it is going slowly worse.

I'm waiting to recive the new temperature sender(which i have ridden here is the cause of the hot start problem) and new coolant termostat.

My fuel leaking problems are the injectors or the return hoses ( that i changed ) and not the engine itself. I only have to clean the engine from dirt to have a better "point of view ".

And yes i will try to find someone that can scan the computer.  May i use an obd 2 plug to comunicate with torque app?

 

1 hour ago, Zimo said:

May i use an obd 2 plug to comunicate with torque app?

No. Felicia is OBD-1. You have to use a VAG-COM interface and VAG-COM 409 software on a laptop.

I was suspecting that....sigh

 Ok i will let a dealer scan it!

Nothing that i may check first by myself? 

 

I my opinion there is nothing more you can do at this moment. There are too many things that can be attributed to as the cause for bogging down at that particular phase of driving. It seems to me that the problem is actually present all the time but it goes unnoticed unless a very light load is needed. The car bogs down when not enough fuel is provided or better said when there is too much air in the fuel. For instance let's suppose there is a very small quantity of air trapped in the system after you have changed the filter. That small quantity of air doesn't count when lots of fuel goes into combustion chamber but when a very small quantity of fuel is injected that counts a lot.

Edited 7 July, 20196 yr by RicardoM

7 hours ago, RicardoM said:

I my opinion there is nothing more you can do at this moment. There are too many things that can be attributed to as the cause for bogging down at that particular phase of driving. It seems to me that the problem is actually present all the time but it goes unnoticed unless a very light load is needed. The car bogs down when not enough fuel is provided or better said when there is too much air in the fuel. For instance let's suppose there is a very small quantity of air trapped in the system after you have changed the filter. That small quantity of air doesn't count when lots of fuel goes into combustion chamber but when a very small quantity of fuel is injected that counts a lot.

So just to understand :  even if the pickup starts and run(for around 700km) there could be have remai a small amount of air in the circuit ?  I have bleeded the air from the bleeding nozzle on a hose over the fuel pump but that nozzle was some kind of strange , not so firm (i dont know how to explain) like the hole has the wrong thread for the nozzle but some how it screws on. Could it be the wrong nozzle? Is it needed a gasket/ o'ring between hole and nozzle? 

Sorry for my poor explanation

 

On other hand,Could help cleaning the EGR valve?

 

Just another info, which is the best complete process to drain water from the filter? 

Thanks 

Edited 7 July, 20196 yr by Zimo

2 hours ago, Zimo said:

So just to understand :  even if the pickup starts and run(for around 700km) there could be have remai a small amount of air in the circuit ?

Yes. Probably letting air in too.

2 hours ago, Zimo said:

I have bleeded the air from the bleeding nozzle on a hose over the fuel pump but that nozzle was some kind of strange , not so firm (i dont know how to explain) like the hole has the wrong thread for the nozzle but some how it screws on. Could it be the wrong nozzle? Is it needed a gasket/ o'ring between hole and nozzle? 

Sorry for my poor explanation

The illustration below from the workshop manual might help.

2 hours ago, Zimo said:

On other hand,Could help cleaning the EGR valve?

Of course. It was next on my list but I didn't know how good DIY mechanic are you. Cleaning carbon deposits on EGR valve and also on throttle plate will help the engine run better.

I'm not a mechanic at all but like to work on my car....

Many thanks for the pic!

So first do i have to drain air that would be stuck in? How? Craking inkectors? Bleeding nozzle?  After this i'll drain water from filter(bleeding the air from the nozzle on the hose).

After i would like to clean the egr, taking it out , using a carbon cleaner and see what heppens.

Right? 

What you mean for throttle plate?

Many thanks

Ps: where i can find that workshop manual?!😁😁

Edited 7 July, 20196 yr by Zimo

2 hours ago, Zimo said:

So first do i have to drain air that would be stuck in? How? Craking inkectors? Bleeding nozzle?  After this i'll drain water from filter(bleeding the air from the nozzle on the hose).

I would have expected Diesel owners to join the discussion on this topic. They should know better.

2 hours ago, Zimo said:

After i would like to clean the egr, taking it out , using a carbon cleaner and see what heppens.

Right? 

Right.

2 hours ago, Zimo said:

What you mean for throttle plate?

Sorry my bad, got carried away, it's a Diesel.

2 hours ago, Zimo said:

Ps: where i can find that workshop manual?!

For now it is in my possession and few other Briskoda members. It is about 500 MB. See PM.

Thanks Ricardo only re-reading your last i saw the quote from the other thread! So now i will ceck fuel lines! ( do you understood which line refers the guy in your quote?)

Many thanks

You'll have to check all fuel lines.

Did you manage to replace old/faulty parts so far?

No i only replace the piping tubes of the return fuel over the injectors.... clean the engine but until now still having the issue. I will drain water from the filter this weekend and i see. Than i will take a closer look when some suspension parts will arrive( as well as new temp sender and new thermostat) and i will put the pickup on jack stands , so i will able to check the underbody fuel lines.

Just another observation: when the water running warm(actually around under 90°C where i suppose it has to run when thermostat works right)  the problem seems to be less strong....

Edited 11 July, 20196 yr by Zimo

It seems that no injector leaking.... also i'm waiting to recive the egr cleaner, so i have to disassemble alsothe egr 😑🤣🤣

15 minutes ago, Zimo said:

Just another observation: when the water running warm(actually around under 90°C where i suppose it has to run when thermostat works right)  the problem seems to be less strong....

That is why I've asked about parts replacement. To check if something changed for the better.

Little update

New thermostat and temp sender(green band) arrive, i miss only the coolant liquid and i can change them. which will be the right color? I have pink(or mybe red) is it right?

Working on jack for the frontend , i have checked the underbody diesel tubing and seems ok.

But fuel consumption seems increase so maybe the Egr valve is not working correctly? I have bought a egr cleaner and i want to check the actuator tubing.... hopefully.....

4 hours ago, Zimo said:

But fuel consumption seems increase so maybe the Egr valve is not working correctly?

Food for thought

4 hours ago, Zimo said:

New thermostat and temp sender(green band) arrive, i miss only the coolant liquid and i can change them. which will be the right color? I have pink(or mybe red) is it right?

IIRC I've shared Skoda Felicia Workshop Manual with you.

 

The link is for real a "food for tought"! And also answer to other question !

The coolant liquid is just for chat, i will check on the manual! 

Many thanks

So yesterday night i changed the thermostat....now temperature it goes up better but sits just a little bit above 90°c 🤣 and when on uphill i think it goes about 2mm above. Than goes back .... and this with fresh air of the night and morning.

The coolant liquid i found is yellow but it is premixed so i want to change another time. Last night taking a shake down drive the temperature stay 3/4 mm above 90c so i just try the heater and the temperature goes down. This resulting also in mixing coolant that probably was in the heater piping and now i got green liquid as the previuos was light red.

So i will also try change the temp sender and flush with new coolant to see if the sender read bad .

I have also bleed the fuel filter(200ml that i left in clear can to see if there was water) and i notice that the bleeding nipple is very "strange": unscrew a quart of a turn with the vacuum pump connected the nipple has a play and i have to push it up to let the fuel flow out and it has a lot of air bubble( like foam) . I drained about 400/500 ml of fuel and engine fire up quite easily( i have to fire it 2 times becuse at first it starts than cut off and then fire and stay on) . So this means it can be other air stuck in the circuit? May be i have to replace the nipple?

More over, 2 or 3 weeks ago i washed the engine and since then only 1 injector seems to be coming back very very little oily on its body .

Until this morning driving to work the engine still bogs , but something seems to be slightly changed... 

Now i will try to clean the egr valve and change the temp sender.....

Opinions!? 

Regards 

 

1 hour ago, Zimo said:

Now i will try to clean the egr valve and change the temp sender.....

OK on EGR valve. Not yet on CTS as it is VERY dependent on two things: air pockets and correct level of coolant in reservoir. Other things that may influence the readings are: debris in front of the radiator, radiator air deflector missing, old radiator hence poor cooling, and debris inside cooling system. I think the CTS is good.

1 hour ago, Zimo said:

So i will also try change the temp sender and flush with new coolant to see if the sender read bad .

When changing the coolant type it is mandatory to flush the system with water first

1 hour ago, Zimo said:

May be i have to replace the nipple?

It is your call but from your description it looks you are onto something.

 

As always many thanks @RicardoM

I think is enough to speak abouy debris 😭😢😅 removed the tank and washed.

ok so knew flush with water. 

So i have to :

Discharge actual coolant buy the bolt under

Put knew water e discharge

Put knew coolant 

Right?

Driving for 5min to my parents house , it seems that the "bogs style " is a little more present and the smell of diesel much hard.

Do you think i have to change the nipple?

Edited 30 July, 20196 yr by Zimo

39 minutes ago, Zimo said:

I think is enough to speak abouy debris 😭😢😅 removed the tank and washed.

I was talking about debris in the cooling system. Radiator, heater, pipes, etc.

As for the rest, I hate to repeat myself.

1 hour ago, Zimo said:

Driving for 5min to my parents house , it seems that the "bogs style " is a little more present and the smell of diesel much hard.

Do you think i have to change the nipple?

I don't know where it is (needs physical access to vehicle) but I'm sure you have an air leak into the fuel feed somewhere.

Yes the picture is of the expansion reservior. Seems like there was debris dark gray that i washed before refill with new coolant 

2 hours ago, KenONeill said:

I don't know where it is (needs physical access to vehicle) but I'm sure you have an air leak into the fuel feed somewhere.

May be is the bleeding nipple...

Hello everybody! I didn't have give up on the felly , but i'm working on the bed becuse of the weather that allow me to work outside....

Referring to the main reason of the topic ,during the work on the bed i found the fuel tank vent pipe to be clogged by mud so cleaned up but i 'm not able to take a test drive due to bed needing to be welded.... could it be the clogged vent pipe a reason of bogging?! The restoration continue!....