1987 volvo 244 DL idles fine, stutters and backfires at highway cruise speed
Alex Bonne
No problem starting. However yesterday at highway cruise, momentary
loss of power occured at irregular intervals, accompanied by
occasional backfires.Power loss duration was from split second to up
to 20 sec.
About 2 weeks back, the Smog check mechanic stated that the hoses to
the evaporation canister are cracking. He also adjusted the timing by
several degrees, making what I thought to be an occasionally rough
idle.
4 yrs ago, I replaced the failed original air mass meter.
Could the problems described above be from the evaporation canister
hoses being more severely cracked? What is the function of the evap
canister during highway-speed cruising?
My first suspicions are for air mass meter, but the fact that cracked
hoses exist on the evap canister make me want to understand that
system better.
Any help appreciated!
Jon Robertson
SHOULD BE ON THE RIGHT .Clean every thing including the idling motor control
thingo it get gummed up .Its under the intake manifold with simple
electrical connections and hoses coming out of it .I swirl cleaning fluid in
it and make sure its free of grit .Its is like a motor inside but only turns
a bit to allow air correction .Hoses are a must cheap and simple the
evaporator cleans the hydro carbons out of the air back into the mixture
rather than vent them out side .My Volvo is 12 degrees before top dead
centre ,which is correct .Maybe your is different but make sure hes not far
from the mark as it ruins the preformance .
"Alex Bonne" <al2.71...@gmail.com> wrote in message
news:ee0ade10-97ce-4440...@u18g2000pro.googlegroups.com...
James Sweet
Has the outside of the harmonic balancer spun on the rubber damper? That
can make the timing way off when the mark shows it to be just right.
'87 is also one of the years with the biodegradable engine wiring
harness, I've had to replace several of those, the car will never be
dependable with the original harness, the insulation crumbles all over.
I rebuilt a few by splicing in all new wires from near the firewall to
all the connectors since the cars broke down.
Alex Bonne
> IT STUTTERS BECAUSE YOU PUT THE STEERING WHEEL ON THE LEFT SIDE WHERE AS IT
> SHOULD BE ON THE RIGHT .Clean every thing including the idling motor control
> thingo it get gummed up .Its under the intake manifold with simple
> electrical connections and hoses coming out of it .I swirl cleaning fluid in
> it and make sure its free of grit .Its is like a motor inside but only turns
> a bit to allow air correction .Hoses are a must cheap and simple the
> evaporator cleans the hydro carbons out of the air back into the mixture
> rather than vent them out side .My Volvo is 12 degrees before top dead
> centre ,which is correct .Maybe your is different but make sure hes not far
>
> news:ee0ade10-97ce-4440...@u18g2000pro.googlegroups.com...
>
>
>
> > Symptoms as described above: At idle, the car sounds and behaves fine.
> > No problem starting. However yesterday at highway cruise, momentary
> > loss of power occured at irregular intervals, accompanied by
> > occasional backfires.Power loss duration was from split second to up
> > to 20 sec.
> > About 2 weeks back, the Smog check mechanic stated that the hoses to
> > the evaporation canister are cracking. He also adjusted the timing by
> > several degrees, making what I thought to be an occasionally rough
> > idle.
> > 4 yrs ago, I replaced the failed original air mass meter.
>
> > Could the problems described above be from the evaporation canister
> > hoses being more severely cracked? What is the function of the evap
> > canister during highway-speed cruising?
>
> > My first suspicions are for air mass meter, but the fact that cracked
> > hoses exist on the evap canister make me want to understand that
> > system better.
> > Any help appreciated!
Thank you for the input; I'll check the timing again, perhaps with a
better mechanic than I am. Also tonight in a more diligent inspection
of the engine, I found the hose between the evap canister and the
intake manifold was completely severed. Bought a new length, and will
install it shortly.
The idling motor control you mention: do I need to remove it to clean
it, or can it be cleaned in-situ?
Alex Bonne
Thank you for the hints! I'll check the wiring for cracks.
How would I tell if the harmonic balancer has spun? Is there another
reference for comparison? Not too familiar with this one...
Mr. V
> How would I tell if the harmonic balancer has spun? Is there another
> reference for comparison? Not too familiar with this one...
Here ...
http://www.swedishbricks.net/700900FAQ/Engine-Mechanical1.html#Failure_of_Harmonic_Balancer
James Sweet
>
> Thank you for the input; I'll check the timing again, perhaps with a
> better mechanic than I am. Also tonight in a more diligent inspection
> of the engine, I found the hose between the evap canister and the
> intake manifold was completely severed. Bought a new length, and will
> install it shortly.
> The idling motor control you mention: do I need to remove it to clean
> it, or can it be cleaned in-situ?
Yeah definitely replace any cracked hoses, those aren't helping anything.
You might be able to clean the IAC valve in place but you'll save
yourself time and headaches by removing it, there's only two bolts to
loosen, a couple of hose clamps and an electrical connector.
James Sweet
> Thank you for the hints! I'll check the wiring for cracks.
> How would I tell if the harmonic balancer has spun? Is there another
> reference for comparison? Not too familiar with this one...
You can set the engine to TDC by looking at the mark on the cam pulley
which you can see if you remove the screw at the top of the timing belt
cover and pull the cover away a bit. With it lined up with the mark on
the backing plate the mark on the crank pulley should line up with the 0
mark on the lower cover.