4g54 ignition timing

[gunnerzz]

I was helping my dad's friend with a problem with his lo47 pajero on 4g54 engine.
He complaint about lack of power.

I check the ignition and it was a mile off at beyond 10degree after tdc.
I reset the ignition to 7btdc and was surprised that the engine backfires so i retune to 5 btdc and let him have a go.he said no improvement and the engine is idling badly and it still backfire.

So,i set it at 7 after tdc and the engine becomes smoth.
This time i went with him for a test drive.i can feel the power is back.
I was waiting for the engine to knock as its not the correct ignition setting but to my surprise the engine did not knock.
Not even when he rev it high.

I there something i miss?

 

[Izso]

I'm not familiar with the 4G54. Is it a carb or EFI?

 

[^pomen_GTR^]

bad distributor?

 

[vr2turbo]

Probably the compression of the engine is already weak. I used to advance the timing of my old Accord to run better at low to mid end but suffers at high end, but I usually use the car in town

 

[gunnerzz]

4g54 is carb fed.
My initial thought is the distributor too but the owner seems reluctant to believe as he said the distributor is less than 3 yr old.

just now he said the engine is sometimes jerking at low rev which again led me to believe its the distributor.

btw i did suspect something is not right with his carb which is an iswara unit modded to fit on the 4g54 but dismiss it as soon as the engine run smooth at 7 after tdc.

 

[^pomen_GTR^]

4g54 is carb fed.
My initial thought is the distributor too but the owner seems reluctant to believe as he said the distributor is less than 3 yr old.

just now he said the engine is sometimes jerking at low rev which again led me to believe its the distributor.

btw i did suspect something is not right with his carb which is an iswara unit modded to fit on the 4g54 but dismiss it as soon as the engine run smooth at 7 after tdc.

tuning is the only solution after mix-n-match...

both ignition and carb mixture...probably will get even better if the carb alsu tuned...

 

[gunnerzz]

tuning is the only solution after mix-n-match...

both ignition and carb mixture...probably will get even better if the carb alsu tuned...

Well,he was just at my house to borrow my timing light.
guess its just a matter of time before he accept that his distributor is the cause.

the engine was running fine after the conversion and only recently it behave like that.
he adjust the timing 1st using sight and sound which is why the timing was way off when i check it.

guess its the distributor then.

 

[AlexKen]

The timing mark ngam or lari? I have kena this timing issue before because of the pulley mark not at 0degree when TDC... And iswara carb fit in a 2.6L block? :hmmmm2: Really need a proper tuning i guess....