Help me to solve this..

[Vishva]

I have modified and fully rebuilt engine of my nissan march k10.
With new piston,rings,bearings etc...
But it has big problem,
Fuel mixture(flue gas) spread out from carburetor air intake when only accelerating..
At ideal speed engine runs normally.

 

[frank]

have you got a vid of it vishva ?

 

[Vishva]

Yeah,I will send u a link of the video..

 

[Vishva]

have you got a vid of it vishva ?

https://m.facebook.com/story.php?story_fbid=10155698504252843&id=314037332842

 

[John_D]

Sticky/badly seating inlet valve? Cam shaft timing out? (cam to crank TDC)

 

[Vishva]

Sticky/badly seating inlet valve? Cam shaft timing out? (cam to crank TDC)

I thought as well as u,so I have double checked TDC marks according to technical manual,then All the valves were grinded and smoothed,but the problem isn't vanished.please give is there another problem..

 

[John_D]

I thought as well as u,so I have double checked TDC marks according to technical manual,then All the valves were grinded and smoothed,but the problem isn't vanished.please give is there another problem..

Well obviously one or more inlet valves are not fully closed when the pistons start to rise ......valve clearances too tight/non existant then?

 

[frank]

yes it does sound like the cam is retarded a couple of teeth, have you checked the tdc pulley mark with a screwdriver down the plug hole ?
and checked the inlet is starting to open and the exh nearly closed on cyl 4 ?

 

[Vishva]

Well obviously one or more inlet valves are not fully closed when the pistons start to rise ......valve clearances too tight/non existant then?

Tnx dear,I have already kept valve clerances high.about 0.5mm,please tell me how to find valve leak from which one..

 

[Vishva]

Yeap dear

yes it does sound like the cam is retarded a couple of teeth, have you checked the tdc pulley mark with a screwdriver down the plug hole ?
and checked the inlet is starting to open and the exh nearly closed on cyl 4 ?

 

[Vishva]

Yeap dear

Dear frank ,first i kept timming sharp correct,
Then step by step jump T belt 1 and 2 teets advanced and retard,but issue still there.

 

[frank]

and have you done a compression test vishva ?

 

[Vishva]

I haven't proper equipment for compression test,but I kept my thumb on spark plug hole and rotate manually,I think compression ok.but tell me another way to check compression..

 

[frank]

i usually roll mine down a hill in gear to test for 1 or 2 low compressions (handy for diesel engines) select a gear that rolls about walking pace, and feel for 4 equal resistances

 

[Vishva]

i usually roll mine down a hill in gear to test for 1 or 2 low compressions (handy for diesel engines) select a gear that rolls about walking pace, and feel for 4 equal resistances

Thanks.

 

[Vishva]

Finally I found a solution.
Today,
First i removed no1 spark plug,then start the engine and problem solved little,
Next step removed no2 spark plug ,after that problem vanished completely.As a result,I determined there was inlet valve leak from no 1 and 2,,,Thank all for helping me.

 

[frank]

have you tried swapping the plug leads on 1 and 2 vishva ?

 

[Vishva]

No,u got wrong idea,plug hole was fully opened one by one,Therefore no compression in cylinder,so no pressure act on air intake due to inlet valve leakage,have got the theory bro..

 

[John_D]

No,u got wrong idea,plug hole was fully opened one by one,Therefore no compression in cylinder,so no pressure act on air intake due to inlet valve leakage,have got the theory bro..

I would suspect a head gasket blow between No1 and No2 cylinders, due to either a warped head or cylinder head bolts in that area not torqued down correctly........

 

[plmval]

I would suspect a head gasket blow between No1 and No2 cylinders, due to either a warped head or cylinder head bolts in that area not torqued down correctly........

"On the money" either way, a croc of extra time, work & expense?

 

[frank]

i suspect 2 bent inlet valves personally, a result of trying different tooth settings

 

[John_D]

i suspect 2 bent inlet valves personally, a result of trying different tooth settings

Not sure that fits in with
quote:-
'First I removed no1 spark plug,then start the engine and problem solved little,
Next step removed no2 spark plug ,after that problem vanished completely'
Either way the next step has got to be remove the head and do an inspection.......

 

[frank]

compression would leak out of the sparkplug hole and not back through the carb, and more-so with both plugs removed.
the engine sounded like it was running on 2 in the vid, and may have been running on 2 since the rebuild (hence my suggestion to swap sparkleads 1 and 2)

 

[John_D]

compression would leak out of the sparkplug hole and not back through the carb, and more-so with both plugs removed.
the engine sounded like it was running on 2 in the vid, and may have been running on 2 since the rebuild (hence my suggestion to swap sparkleads 1 and 2)

Definitely wouldn't hurt to try it, always do the simple things first, though I thought that the OP had discounted this? . Firing order 1,3,4,2 ?

 

[Vishva]

Problem solved....
I take few days and repair the fault completely..

First,remove head from engine body,
Then check all the valves and grinded all with lapping paste,
Clean the head and reinstall all the valves
Then mount head and keep valve clearance to 0.22 at hot,
First valve 1,2,3,6 set while 1piston at compression and keep TDC 0° mark.
After one full turn set valve clerances of valve 4,5,7,8.
Reassemble all the components and ready to start.
Ooooooh ,,ooopps engine gives same problem,I was disappointed..
By the way,my father was given best idea..
Then we remove the exhaust manifold start,
Sounds good,engine start and running good no any problems....
Then we determined faulty may be at manifold..
Then we disassembled catalist converter,
Problem found.oil carbon inside the converter blocked,
Clean all and fixed that problem..
Reasons ,,, problem of the catalist converter,
Faulty ,due to blocked exust manipolei
Burnet gas no where to go so at inlet valve open pressure air come to inlet manupole that was reason for mix come from carburetor inlet,
Thank u brothers

 

[plmval]

Catalyst converter can be cleaned out at no cost with detergent in a bucket and when running with lacquer thinner ?

Reference:

Enjoy