Could an exhaust leak.....

[Rot Box]

Could a totally blown out on one cylinder exhaust manifold gasket show similar symptoms as a bad vacuum leak?

I'm working on a friends 79 Toyota pickup 20R and its getting a very erratic idle under 1800 rpms. vrooommmm blubbb blubbb blubb vroooommmmm blubbb blubbb blubbb.... Over 2k it runs decent. Getting plenty of fuel, checked for vacuum leaks with water, timing is spot on and valves clearance checks good. Any ideas I'm getting sick of messing with it Thanks,

Andrew

 

[chans]

With as cold as it has been a bad enough exhaust leak could have caused a sucked or burned valve. Did you do a compression test?

 

[bryson]

vrooommmm blubbb blubbb blubb vroooommmmm blubbb blubbb blubbb.... Over 2k it runs decent.

So... what does it sound like over 2k?

What chans is saying makes sense (I think...) But I don't think the exhaust leak itself would have anything to do with the way it runs...

 

[Marsh99]

My sounded like that with a clogged carb