General Head gasket replaced.... new problem now.

[Martron]

i inheritied a 1998 punto s 60.

the head gasket went. anyway between one thing or another it was sitting a month beofre i could fix it.

anyway it was a succesful repair. or so i thought.

the car is still holding its coolant and oil. but began to splutter under acceleration if i eased of the accelerator and put my foot down again it would stop.

not i have 2 ideas. with the water and "gunk " sitting in the cylinder for so long when i cleaned it and restarted it could i have sent smoke or what ever to effect the lamda sensor and this is what is causing the spluttering under acceleration.
OR
is there a piston ring gone. when the car is idling there is no excess emissions but ever so often there is a "pop" . its not at regular intervals either.

the lack of power only happens every so often and only under hard acceleration. so lead me to believe the fault is not constant.
( i could be way off here. but any ideas would be appreciated.)

the car was not cared for previously and i have spent as much money as i probably am going to unless its a diy job. so if it is the piston ring whats the life expectancy of the engine or is there a quick fix.

thank in advance

MArtin

 

[dumbledore]

If is intermittent them it could be electrics. Ignition leads may be a problem. Have a look at the spark plugs and see if they show any signs of misfiring.

 

[Martron]

i took them out the other day and they were black. i cleaned them and replaced them.

i thouhgt this may have been from it sitting up for a long time with all the gunk in it and it would burn off.

i can hear a ticking coming from the engine an electrical tick. but i cant isolate it. i have checked all the leads and they seem to be in place. so i just figure it out.

all the plugs were sooted up so i doubt it was just one plug causing the trouble.

 

[SamuraiDragon]

iirc, black plugs show its been running rich so may be worth looking at the lambda sensor.

 

[Martron]

anyway of checking the lamda sensor. or is it a case i can whip it out and clean it?

 

[SamuraiDragon]

cleaning them isnt recommended as they are very sensitive and dont like to be messed with. one way around it is unplugging it and seeing if it makes any difference. i assume u dont have the engine management light on?

also while ur under the hood, may be worth checking and cleaning the throttle body.

 

[Martron]

there is no engine managemnet light on. but the cars previous owner fancied themselves as a mechanic and i cant trust that that light even works.

 

[colinf1]

u cant really clean lambda sensors, but if its running rich it may have damaged the lambda and cat.

did you service it after you done the head gasket job?

check the car at night, open the bonnet and look for sparks when engine is running, it will help you locate the ticking noise..could be a striped wire thats causing a short.
could also be a break within the HT lead, so you could try by replacing them

 

[MadMan0]

timing belt could be slack..

I took a long time doing my timing when i did my HG last week...
I had a similar sounding issue.. i found that i hadn't tightened the belt between cank pully and cam pully, so although the belt was tight by the tensioner, after turning the engine over, the belt went slack and jump a notch very now and again, worse at higher rpm.

Finally got it sorted when i saw what i was doing wrong

 

[Elliot Ross]

Think your talking about a judder under acceleration?

I had this and I replaced the: HT leads, plugs, lambda sensor and it still did it, I then put in a brand new coil block and it is absolutely perfect now!

 

[DaveMcT]

Measure the lambda switching voltage. This might help
https://www.fiatforum.com/cinquecento-seicento/58467-lambda-voltage.html

 

[Martron]

re timed it.

i think the problem is that i am not geting enough tension into the belt. its running smoothly again.

time will tell!

 

[DaveMcT]

The cam belt should twist 90 degs at mid point on longest run. if its loose it will jump or rip its teeth off.

 

[MadMan0]

if u have a new belt, line the white timing markings up with the timing marks on the crank pullys etc, the tension should be fine on the front side, then adjust the tensioner to get the tension on the rear side of engine
hope this helps

- i pulled the tensioner as far forwards as i could using paillers, the timing for mine is now 100%