Re: running rough and gutless at low rpms

["content22207" <brobertson@xxxx>]

Is it an honest to goodness miss, or something else? (people sometimes
mischaracterize other problems as "misses"). Put a timing light on
each wire, as close to plug as possible. If you've got consistent
spark on each, you don't have a miss. Exactly how does the engine
behave? Misfires happen suddenly and are extremely short duration.
Vacuum leaks cause engine to slowly drag, then catch itself. If you've
got backfire or muffler farts, something's happened to ignition time
(valve clatter can also be a timing problem). If the engine's just
sluggish, or again if valves clatter, you may have fuel supply issues.

Since your problem clears up at higher RPM's, re-check for vacuum
leaks ALL OVER engine (vacuum leaks usually are low RPM problem). PRV
has all kinds of nooks and crannies to suck air though. As I
discovered, is susceptible to vacuum leaks through valve covers. This
also means any point on timing chain cover could introduce air, even
down by the oil pan. Are two access covers on BACKSIDE of heads
(closest to front of car) as well as the one under A/C idler pulleys.
According to tech manual, dipstick tube can leak air. If true, that
means any point around oil pan can have a vacuum leak. Your best best
is to test spray entire engine with carb cleaner, brake cleaner, or
whatever. Even if problem isn't a vacuum leak you'll have cleanest PRV
in town.

Mechanic once told me 99% of car problems are electrical. Have since
found he was correct. General public usually jumps on fuel system
first. Should start with spark plugs and work backwards.

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, "vin2105" <phil@xxxx> wrote:
> My car runs rough and misses at low rpms. It will have very little 
> power until it hits 3k rpms then its fine. I checked the timing and 
> its set fine, checked to make sure that the vacuum advance is 
> working, checked for vacuum leaks.
> 
> Am i looking at a fuel issue, an ignition issue, other issue?
> 
> Anyone got any idea?
> Phil Priestley