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Old September 28th 04, 12:30 PM
Ricky Spartacus
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This matches the description as if you're driving on three cylinders,
intermittently, as most suspected. There's no safe way to check for
spark on the plugs or plug wires on DIS for DYIs, but perhaps one.
Hookup an induction timing light. At low rpm you can observe carefully
the consistent or inconsistent sparks. After finding the inconsistent
cylinder, swap the plugs and try again to rule out a bad plug. DO NOT
LEAN on the car's earth. At the really high voltages that ignition
systems work at, and for unknown reasons, you can get an interesting
shock that you'll remember a lifetime. I had my share.

> Thanks Philip & everyone
> Ok here's some more observations....
> Yesterday I did remove the EGR valve and there was much carbon in the
> valve and pipe. I used Carburator cleaner (sensor safe) to try & clean it.
> The valve seems to move/close more freely thereafter. I also
> replaced the PCV valve (FRAM PV295).
> However as I drove
> to work this morning and the car still felt like it was stumbling when
> accelerating. When gearing up from 1st to 2 & 3 my car hesitates, it feels
> jumpy, or stumbles with a lurching/bucking. My sense is that it
> seems like the clutch plate is slipping. However this symptom does not occur
> consistently. Sometimes it drives/feels very well. But when it happens it
> always does under lower rpm (1600-2500), typically as I am gearing up and
> accelerating with the gas pedal. I do not notice this under high rpm >3000
> rpm or when in gear 4 or 5 (maybe because of momentum). As I stated
> before, I tested the clutch, easing up on the pedal into 1st gear from a
> stationary position either on level ground or uphill, and the clutch does
> grab. Then if I press the gas pedal once in gear sometimes the jerking
> occurs. I cannot say that it appears to be a problem with the fuel pump.
> It primes fine when I turn the key to ACC, and the engine does not seem to
> sputter (like it's running out of gas). I'd suspect the clutch slipping if
> it was consistent. As Philip suggested I'll change the ignition wires to
> see if that does the trick (however when I changed the spark plugs last
> summer I did also measure the Resistance on the wires and they were
> fine). I would rather not spend money on changing the clutch plate or
> fuel pump if it is not necessary as these are very expensive.
> Thanks, Roger


> In article <Pine.LNX.4.44.0409241223250.7871-100000
> @elara.scs.ryerson.ca>, says...
> > I have a 1995 Saturn SL1, SOHC, manual transaxle, with
> > 145,000 Km (much on the hwy). I do change the engine oil frequently
> > 5000Km, check fluids often, etc. In the past two
> > weeks, when accelerating, my car hesitates, it feels jumpy, or

> bucking/jerking.


> > To resolve a recent stalling problem at deceleration and low rpm

> <2000rpm, I did the following:> >
> > - changed fuel filter
> > - cleaned carbon out of throttle body with carb cleaner (was
> > O2 sensor safe), and there was alot of carbon...
> > - replaced vacuum hose between throttle body and crank case, old one was
> > weak & almost ready to collapse. (fuel/PCV line hose 11/32" ID, 50 PSI)
> > -used STP concentrated fuel injector cleaner in gas tank.
> > -spark plugs were gapped & changed last summer.
> > -replace air filter
> > I don't think it is a slipping clutch, because the clutch feels fine and
> > grabs when I ease up on the clutch pedal when starting in 1st gear.
> > Although I feel this bucking in gears 1, 2, 3, not so much in
> > 4/5....typically at lower rpm < 2500 rpm 1500 - 2200 rpm.
> > It could be the ...
> > -EGR valve
> > -ignition wires
> > -cap and rotor
> > -MAF/MAP sensor (where are these located?)
> > any suggestions?
> > Thanks, Roger


> Very good post. You covered a lot to eliminate a bunch of questions we
> here might of had to go through. I kinda suspect the EGR. It may not be
> closing off, at least not very well do to carbon. Btw Saturns never used
> cap and rotors.
>
>
> On Fri, 24 Sep 2004, Philip Nasadowski wrote:
>
> > In article
> > >,
> > Roger Ehrlich - Alumni-2004 > wrote:
> >
> > > - changed fuel filter

> >
> > Good.
> >
> > > - cleaned carbon out of throttle body with carb cleaner (was
> > > O2 sensor safe), and there was alot of carbon...

> >
> > Good. you might want to just remove and clean again to get EVERYTHING.
> > It's 2 10mm bolts and unplugging the cables. Really easy, at least on
> > the dual hamster models.
> >
> > > - replaced vacuum hose between throttle body and crank case, old one was
> > > weak & almost ready to collapse. (fuel/PCV line hose 11/32" ID, 50 PSI)

> >
> > Weird.
> >
> > > -used STP concentrated fuel injector cleaner in gas tank.

> >
> > Maybe it did something. I don't trust those things though.
> >
> > > -spark plugs were gapped & changed last summer.

> >
> > Ooooo.
> >
> > > -replace air filter

> >
> > Good too.
> >
> > > It could be the ...
> > > -EGR valve

> >
> > Maybe.
> >
> > > -ignition wires

> >
> > *ding!*
> >
> > Change those first. I bet the problem goes away. Mine was like this
> > too, i changed the wires - ran a LOT better. It just feels like it's
> > missing or hesitating every now and then, randomly? or, at low RPM, as
> > the RPM increases, it suddenly 'kicks in'?
> >
> > > -cap and rotor

> >
> > None - it's a DIS system. A coil per plug.
> >
> > > -MAF/MAP sensor (where are these located?)

> >
> > No MAF. MAP is on the intake manifold. I'm not sure about the single
> > hamster motors, but the two hamster ones have it to the left end of the
> > manifold.
> >
> > > any suggestions?

> >
> > Replace the plug wires. Do it first. I bet it fixes it.

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