Re: 92 Buick Roadmaster Station wagon "surges" (SOLVED) I believe

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. > >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
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Dan
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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

On Mon, 04 July 2005 10:32:50 -0400, Dan wrote:

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Dan

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