Technical Palio 1.6 16v random pull away flat spot

[Francois01]

Hi all

I'm new here hope someone can help.

My Problem: If I start my vehicle and drive of it has a random occurring flat spot when pulling away (more so when hot). Noticed that if I drive somewhere, say on a freeway, it has no problems even if I get to intersections and so forth. It pulls away no problem but then I stop and shut of. Restarting after a while (5min - 1 hour or more) it happens again.
Did a diagnostic and said possible fuel pump or map sensor faulty, I was adviced to go for the map sensor but no luck :bang:

Flat spot explained: Very low stuttering idling and when I press accelerator it takes 2 - 3 sec for the revs to pick up and has blue/black smoke smelling of fuel.

Got advice that it may be the Lambda sensor but very scared to fork out dough and have it not be the problem again

 

[rikhav]

Do you get a check engine light?

If yes, what are the error codes you get when an examiner is connected

 

[Francois01]

Hi

Nope no engine lights at all. Injector light also comes on at startup and goes off after a few seconds like it always have

 

[rikhav]

Hi

Nope no engine lights at all. Injector light also comes on at startup and goes off after a few seconds like it always have

The black smoke with smell of fuel leads to believe there is lotvof unburnt fuel and the culprit has to be o2 sensor

Still wait for the experts to comment on your thread

 

[Francois01]

Changed the O2/Lambda sensor with universal one but no luck....

I'm such a noob Apparently the computer has to recognize the new part or something like that.

After now driving around a little it seems fine. Gonna test it out for a few days and will share if it remains good

 

[rikhav]

Changed the O2/Lambda sensor with universal one but no luck....

I'm such a noob Apparently the computer has to recognize the new part or something like that.

After now driving around a little it seems fine. Gonna test it out for a few days and will share if it remains good

Has the black smoke stopped? Smell of unburnt fuel?

Has the engine become responsive?

If yes, then i guess the problem is solved

 

[Francois01]

My wife just went out and came back furious.....
Cannot understand that it is fine for that period and then it starts again. black smoke still there just checked

 

[Pieter groenewald]

Het jy toe daai water temp sensor geruil maak hy nog so ?

 

[Francois01]

Where at my mechanic just now. There is fuel in my engine oil which means according to him, that one of my injectors is leaking. So I'm gonna change injectors and will share my results.

 

[Peter Pick-Up]

What year is your car?
The injector light doesn't have to stay on, when the ECU detects a fault.
Have the ECU read to be sure.
Bad sensors, and malfunctioning injectors are almost always present when reading the ECU....
But it maybe a dirty throttle valve, or a bad idle air control valve, common problem on older ( Fiat) engines, and very easy to cure.

 

[Francois01]

Hi Peter

Thx for the reply I have a 2000 model.
I'm planning on removing the injectors tomorrow and cranking the engine with the injectors still on the rail. I've been told that I would spot a leaky injector that way.

I've cleaned the throttle body thoroughly, it was really dirty but the problem persisted. One thing I can add though is that the top part of the intake manifold ( if I can call it that ) where the throttle body connects is riddled with oil. No oil coming from breather or brake vacuum pipe - checked. But I'm told it is because my engine oil is very thin because of the fuel.

 

[Peter Pick-Up]

I have a 2000 model as well.
Some time ago, idle was bad, engine stalling,hesitates etc.
Turned out that the IAC valve was bad.( the black round device, next to the throttlebody).
Found a new one on Ebay, problem solved.


Injectors properly testing is something for experts imo.

 

[Francois01]

My budget is a bit broken due to december and car problems in december

I'm gonna remove the injectors and see, if i don't see anything obvious i'll take them to a expert. Can a bad IAC valve lead to fuel in my cars oil though

 

[Francois01]

Ok removed injectors with rail and cranked the engine. I made a short video just for the heck of it


Now to my naked eye, I can't really see anything wrong. I was told a leaky injector will have a stream and not a misty spray. Wanted to take them for proper testing but they would like my car there to test relay's and so on.
I did notice that some of my plug wires wasn't properly connecting so I fixed that. The flat spot seem gone but it accelerates reluctantly, but it has done so before I removed the injectors. It is smoking less also

My plan: I've replaced the oil and I'm gonna keep my eyes and nose on it to see if the fuel returns and take it from there

 

[Peter Pick-Up]

Again, have the ECU read at a good workshop.
It only takes a few minutes, and you'll know everything you need to fix...
Btw, the 2000 Palio is OBD1, not OBDII.
The OBD port is located in the enginebay above the brake booster.