1995 Saturn SL1 hesitation, lurching

Car: 1995 Saturn SL1 SOHC, standard transmission, 4 cyl.
Mileage 237,000 Km

Symptom: Hard to describe here but perhaps as “hesitation”? Either while
running or at idle, engine seems to hesitate. More noticeable on the
highway, pressing the gas pedal the car will on occasion jerk, lurch,
sputter, or hesitate…. It is not continuous, but only very brief and at
random.

My thoughts:
It does not appear to be the clutch slipping. It does engage well, I can
slowly accelerate uphill engaging the clutch with no lurching at that point.

I last changed the fuel filter at 142,754 Km (July 2004). The Haynes
manual suggests the fuel filter be changed every 48,000Km, but I talked
with a mechanic and he suggested every 100,000Km is OK, so I’m about
near that. The fuel pump sounds OK, nothing particularly different than
usual. I have used fuel injector and fuel system cleaners over the
years, maybe 2-3 times per year. I also have used oil supplements,
Bardahl B2, during the last 2 oil changes, (done every 5-6000 Km). I
hear and feel the hesitation from the engine both at idle and when driving.

The injector coils, cables and spark plugs are OK. I have had a failed
coil before and recognize the power loss that occurs when this happens.
This is not similar.

I failed the emissions test in Dec 2008, and got the conditional pass. 2
tests failed for NO, revealing that the catalytic converter needed
replacing, which I haven’t done yet. The O2 sensor was a little lean but
was within spec. The exhaust seems to have no block from what I can
observe, perhaps it’s partial.

Suspension, steering, brakes are all OK.

Any suggestions?

Much Thanks in advance.

Cheers, Roger

 

NO failure on the emissions could also indict the EGR valve which are known
to fail at about 100K miles. You also do not say when the plugs and wires
were last changed. These are easy to do and if not done recently could be
the source of your hesitation. Lastly, from your comments, the fuel filter
is overdue for replacement, and the air filter should also be changed every
12K miles too.

Bob

 

Thanks Bob

The EGR seems to be in good shape, I cleaned it back in Dec'08 and the
spring is good. The plugs (RC14YC), wires and PCV valve, were also
changed in Dec @ about 230,000Km. The air filter was changed in Aug'08 @
223,000Km. I'll get the fuel filter changed.

Cheers, Roger

air filter was also changed in Dec

 

My vote is for the CAT.
I replaced mine at 165,000 Miles on my '95 SW1. Same symptoms, and
that loud coffee can full of rocks noise on accel.
If you do go this route buy a DIRECT FIT that comes with the pipe that
bolts onto the exhaust manifold. It will save mucho time and
frustration. Check Rock Auto for the "Walker" brand.

Scott

 

Thanks Scott
Will do, since my CAT needs replacing anyway before the next emissions
test I'll get it replaced. .... looked up the Walker CAT on
http://www.walkerexhaust.com/catalog/ExhaustCouponScreen.asp

May as well get the fuel filter changed too. If that gets clogged the
engine is starved of petrol. I do not seem to be at the severe point yet
were there is a strain on the fuel pump. I've heard that before back in
2004, which was resolved by a fuel filter change.

I replaced my EGR before in 2004 too. The symptoms then were stalling
when decelerating the car down to a stop. I'm not experiencing that.

Cheers, Roger

 

Clean up the throttle body while you are doing the other work. A dirty TB
usually results in an erratic or misfire during idle, but not during
acceleration.

Bob
..

 

Resolution & Cause:
Bob suggested also the spark plug cables…..

I regularly check & replace the plugs & cables…. Cables in Fall’07,
plugs in Dec’08.

Spark plug cable for cylinder #3 was momentary open circuit, thus
sporadic misfires; damaged connector broke off burning at connector to
spark plug. Resistances of both the ignition coils and other cables were
in spec. I’ve had open circuit problems with the spark plug cable for
cylinder #3 (the short cable) twice before (brand Niehoff). Thus cable
replaced.

I also cleaned the throttle body, it was in good condition and I do this
regularly. I also examined and cleaned the EGR valve again, some carbon
(expected) but the spring was in good shape.

Car runs fine now.

I’ll change the CAT & fuel filer in the near future.

Thanks & Cheers, Roger

 

Great! Glad to hear that you could keep that 14 year old vehicle running
.... As I recall, yours is pretty low mileage so as long as you don't live
in the rust belt, you should be able to keep it going a few more years!
Just keep the oil full and the engine should keep on going.

Bob
..

 

Actually my mileage is quite high..... > 237,000 Km .... and I live in
the great rust belt of Canada..... our Saturns have the plastic body
panels though.... I occasional get some rust on the door rocker
panels.... but treat everything with rust inhibitors.

Just to elaborate folks....

Sorry but the symptom was hard to describe. It was not really a
continuous hesitation.... I've had that before when a coil or spark
cable fails outright... I had good power and acceleration.... there was
a random lurch like the car was losing power for less then a second then
would continue....

It was the Spark plug cable for cylinder #3 that was momentary open
circuit.... it was failing... I could see the burn mark at the failed
electrical connection point in the cable as when I removed it to test
the plug connector broke off and was stuck on the spark plug..... I
could see the burn mark on it too.

Just to help other folks with the library of knowledge for auto
troubleshooting.

Take care folks.

Cheers, Roger

 

Where is the EGR valve on the SL1? The EGR valve on my '93 SL2 is
clearly visible, but I have no idea where it is on my '96 SL1.

 

Driver's side end of the cylinder head.