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Has it Skipped a Tooth?

jnr32r

By jnr32r,
in Engines & Forced Induction

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jnr32r Proficient

jnr32r

Posted
Posted

Installed the Poncams on the weekend.. all went in fairly smooth.

Took it for a good 1hr drive and on the way back after reving to 7000 rpm in 2nd as we came to a traffic lightm, car stalled and would not idle anymore...

At first i thought a cooler pipe popped off but after close inspection its all in correctly.

Question is what is wrong with it?

Symptoms:

Car starts after having to tap accelerator but does not idle.

Will hold revs above 2000rpm if accelerator held but any lower and it stalls

Sounds as if its under a load under 2000rpm

Drives ok above 2000rpm

Timing is ~ 30deg at around 1600rpm.

Tried moving CAS without any improvement...

Timming Belt seems a little loose, moving belt up & down between the cam gear and the tensioner theres about 1cm play.

Could it have skipped a tooth???

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https://www.sau.com.au/forums/topic/78542-has-it-skipped-a-tooth/
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BHDave Grand Master

BHDave

Posted
Posted

Easiest check will be to remove the top timing cover and rotate the engine so it is sitting with cylinder one at TDC (0 on your crank timing mark) The cam gears should have the timing mark line up with a pair of marks on the back of the cam cover (sounds a bit vague but you'll see what i mean).

It sounds like your belt is a bit loose too so you'll probably have to tension it up while you're there.

NZM.031 Grand Master

NZM.031

Posted
Posted

when put the belt on did you rotate the engine and then recheck the belt. 1cm of play?? that sounds very excessive and very well could have skipped a tooth or number of teeth. was it idling when you put them in?? has it only happened when you revved it out?

line the marks up and see what they look like

cheers

Linton

jnr32r Proficient

jnr32r

Posted
  • Author
Posted

thats where i F%^$ up cos i didnt turn the motor, only did the tensioner up....

I drove it for about an hour and it was fine, until one big squirt in 2nd to 7000rpm...

is there a way of knowing if i line the crank pulley to TDC without the back cam gear plate?

BHDave Grand Master

BHDave

Posted
Posted

If your belt is a new genuine one it will have marks on it that line up against the cam gears.

Even if it's a bit old you should still be able to see the marks if you look closely.

I dont know for certain that a non genuine belt will have the marks.

Sydneykid Grand Master

Sydneykid

Posted
Posted
It only matches up to the marks on the belt on installation, after the motor has turned it prolly doesnt return to that position for another 345235 turns....

no back plate as in pic

About 4 turns and the marks on the belt line up on mine.:)

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