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