Hi, I could use some clear suggestions.
My 92 Buick road master station wagon with a 350 engine and TBI
surges. This means I am going alone the highway at 55/60/65 and you
can feel the car just slightly trying to go faster then slower then
faster then slower. Nothing which has an effect on the speedometer or
the tack. But I can feel it.
Combined with the above is the additional symptom. When first
bringing the car up to highway speed; it hits about 55 then really
surges. Bad. Feels like not enough fuel for the engine. I must
floor the gas, then it clears up and all is ok from then on except
for the previous mentioned symptoms.
Oh, there are NO error codes when I test for them.
I have changes the dist cap and rotor and am in the process of plugs
and wires. I am trying to do 2 plugs a day ( have 6 to go). They are
hell to replace. I have also retimed and set it to TDC.
My thoughts are running alone the lines of the Ignition coil ($16 us)
or the injectors (2 at $35 each).
I have also considered the O2 sensor (but no error code) and the TPS
(but again no error code).
Has anyone else had problems like this? What was your solution?
Thank You ---- Dan
Dick C - 06 Apr 2004 02:20 GMT
Dan wrote in alt.autos.gm
> Hi, I could use some clear suggestions.
>
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>
> Has anyone else had problems like this? What was your solution?
I had a Plymouth Voyager that would exhibit similar characteristics,
except that as time went by the surging at 60 plus got a lot worse.
That threw out a code for the heater circuit on the 02 sensor.
Replacing the 02 sensor cured it up. The first time it happened I paid
for 3 hours of labor for trouble shooting it at the dealer. But the
sensor was under warranty. The second time I spent an hour of my own
time checking all the wiring, and bought a sensor myself.
I also put in new plugs, wires, distributor cap and rotor, all to no
avail.
Could also be the fuel pump, according to a website with some trouble
shooting on it.

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Dick #1349
Damn it . . . Don't you dare ask God to help me.
To her housekeeper, who had begun to pray aloud.
~~ Joan Crawford, actress, d. May 10, 1977
Home Page: dickcr.iwarp.com
email: dickcr@comcast.net
W. Orr - 06 Apr 2004 07:44 GMT
>Hi, I could use some clear suggestions.
>
[quoted text clipped - 3 lines]
>faster then slower. Nothing which has an effect on the speedometer or
>the tack. But I can feel it.
I had something like this that since I drove alone on the highway, no
one else was with me to feel it. I'd often just set my cruise control
to 55 and lean back, but on a very smooth highway with supposedly a
constant speed going down the road, I felt something that I kept
describing as 'slight loss of power, slight gain of power, slight loss
of power, etc.'-lasting about second each interval. It was rhymthic
and constant, but very subtle. I ended up figuring out what it felt
like to better describe it:
"It almost feels like the car is breathing."
Sounds similar to a thing that was happening in my 3300 91 Olds Ciera,
as well. I don't know WHAT brought about the fix, but it vanished
about a day after having an intake manifold gasket replaced--as well
as about a month after a tune-up and transmission flush. So it could
be just about any of the three things, or none of them, that solved it
for me.
>Combined with the above is the additional symptom. When first
>bringing the car up to highway speed; it hits about 55 then really
>surges. Bad. Feels like not enough fuel for the engine. I must
>floor the gas, then it clears up and all is ok from then on except
>for the previous mentioned symptoms.
I think my Ciera was doing the same as well. I actually haven't
driven it that much in the last few months (since the gasket) to be
able to quote whether it's still doing that or not, but I was told by
a shop that my fuel pump was operating on the 'low end of tolerance' a
few years ago--haven't gotten it checked since, though. Could tie in
with another poster's thoughts on it being a FP issue.
*shrug*
But I'm far from being an auto expert, though.
Joseph Oberlander - 06 Apr 2004 08:54 GMT
> Hi, I could use some clear suggestions.
>
[quoted text clipped - 11 lines]
>
> Oh, there are NO error codes when I test for them.
This is common on this era engine - no codes.
Sounds like a dying MAF. The fuel/air mixture is electronicaly
controled, so when the main sensor gets old, it can't keep
a steady idle.
Dan - 12 Apr 2004 18:09 GMT
The Solution, So far so Good
I still have had no Error codes. Have changed the coil, Dist Cap, and
Rotor plus the TPS. Still had same symptoms. I replaced the plugs
and plug wires. A really time consuming job. The old plugs were
gapped at greater then .075 I gapped the new plugs at .035 After
replacing the plugs and wires, the surging went away. Still have not
touched the 02 sensor. I still have a Injector that drips when the
engine is off. I assume it leaks when the engine is running. I will
replace it when I have the time.
Just thought I would let you folks know what may have fixed the
problem.
>Hi, I could use some clear suggestions.
>
[quoted text clipped - 25 lines]
>
>Thank You ---- Dan
Dan - 04 Jul 2005 15:32 GMT
Solved, I believe?
I got down to a possibility which suggested the knock sensor was
defective. If so, the timing would be changed at different times. I
disconnected the knock sensor and the surging disappeared. I haven't
purchased a replacement yet since they are $50 at AutoZone. I also
have no error codes with it disconnected and the car runs super. Gas
mileage has gone up about 2 miles per gallon but this may be due to
other factors as summer time.
I really discovered this answer because I had the cat converter top
cover come loose and rattle at times. I believe the rattle would make
the knock sensor believe it was hearing a ping from the engine and the
sensor would retard the spark. Once I removed the cover, the surging
which had been really bad became less worse. I then asked myself what
would be a relationship between the rattle and surging. The knock
sensor became a possible answer.
Took a hell of a long time to solve this.
p/s, I don't want to hear reply's about the damage to the engine with
the knock sensor disconnected. If you have substantial proof say so
and let's see the testing results.
Dan, And have a good 4th of July
>Hi, I could use some clear suggestions.
>
[quoted text clipped - 25 lines]
>
>Thank You ---- Dan
Dan - 30 Sep 2005 14:36 GMT
To cut a long story short.
The road master would tow a horse trailer weighing 1650 lbs
and 1 horse of about 1200 lbs without problems. The transmission
shifting issue became apparent when the second horse (another 1200 lbs
was added). The tranmsiison began to growl (my daughters words) when
going up hills.
I ordered and installed another knock sensor and the wagon
runs great, Transports both horses for 1/2 hour or so to shows and no
odd sounds, gets about 14 miles to a gallon when towing. This is what
the road master is used for. We always have all the horsy stuff in
back.
I guess my message is "change the knock sensor if you are
having surging problems" and you have tried the many other things. Or
just disconnect it for a test run. As a caution, the sensor is
inserted into the water jacket and if removed will drain almost all
the antifreeze before you realize it. I took the opportunity to
change both radiator hoses, the antifreeze, and thermostat, also one
heater host.
My MPG on 600 mile trips without horses is about 19/20 mpg.
P/s roar master has about 176,000 miles on it.
Which I could find an economical electric radiator fan as a
replacement for the existing belt driven fan. The mechanical fan
noise is a little much as I get older and low frequencies are more
prominent in my hearing range. Anyone have one they would like to get
rid of?
Hope this info helps someone, Have a good rest of the summer. Dan
>Solved, I believe?
>
[quoted text clipped - 51 lines]
>>
>>Thank You ---- Dan