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Surging

4K views 20 replies 11 participants last post by  1BAD9C1 
#1 ·
OK, I've spent hours searching threads before I posted this. Between 1500-1700rpms while lightly on the gas peadal the car feels like it surges or like something is holding it back then letting go. Under any other throttle position or rpm it's perfect. It's a 95ss, cold air and flows, thats it. I've already replaced the fuel filter, treated the gas, checked the egr, replaced the wires and plugs(not fun!) removed and cleaned the throttle body and had the local shop run the codes (no codes showed up) The car runs perfect except for that. I parked it for a week and next thing you know this problem arrises. Any and all help is greatly appreciated.
 
#4 ·
another possibility is torque converter clutch shudder.
when its surging just push the brake pedal down enough to trigger the brake lights while maintaining same rpm, if surging stops then thats the problem.
nice thing about the transgo shift kit it gets rid of the pwm clutch control which is one of the causes of tc shudder/surging.
 
#7 ·
Try this, it worked on mine. It sounds just like my 95 ss, I was calling it a hesitation but.......anyway these are two very easy and free things to try.

  1. First (or second, doesn't matter) clean the mass air flow sensor with alcohol (no not whiskey) rubbing alcohol and a Q tip GENTLY! Actually I used a squirt bottle and light air pressure to dry.
  2. Disconnect the vacuum line to the EGR and plug the line.
This removed all hesitation just off idle on mine. If it doesn't work you haven't lost anything and it only takes minutes. I am not sure which made the most difference. I reconnected the EGR and some of it came back. I disconnected again and it runs great again.
 
#11 ·
OK, I've spent hours searching threads before I posted this. Between 1500-1700rpms while lightly on the gas peadal the car feels like it surges or like something is holding it back then letting go. Under any other throttle position or rpm it's perfect. It's a 95ss, cold air and flows, thats it. I've already replaced the fuel filter, treated the gas, checked the egr, replaced the wires and plugs(not fun!) removed and cleaned the throttle body and had the local shop run the codes (no codes showed up) The car runs perfect except for that. I parked it for a week and next thing you know this problem arrises. Any and all help is greatly appreciated.

I've got the same problem... a stuttering/bucking problem when just barely pushing the gas at coasting speed, and one "surge" or almost stall feeling at one position of throttle at first acceleration from a stop, then it takes off with no problem through the rest of the range. Replaced spark plugs, wires, cap and rotor, fuel filter, and air cleaner. No change. I'll be trying some of the suggestions seen in this thread here and will keep an eye on any new developments. Be sure to post if you find something that works. Thanks!
 
#12 ·
Got it! I capped the vacume line at the EGR as suggested(thanks carlrf) the car ran perfect. Gonna purchase a new EGR today. On a side note- whoever designed the ignition system on these cars should be shot. My body is still hurting from doing the plugs and wires! Thanks again for all the help.
 
#13 ·
Got it! I capped the vacume line at the EGR as suggested(thanks carlrf) the car ran perfect. Gonna purchase a new EGR today. On a side note- whoever designed the ignition system on these cars should be shot. My body is still hurting from doing the plugs and wires! Thanks again for all the help.
Just wait till you have to replace a distributor cap and rotor. Then you will really hate things.cwm5
 
#20 ·
I've had a very similar problem with my '95 9C1. After replacing most of the usual suspect parts and still having the same bucking, stuttering, sputtering problem - running erratically and surging on the 2 4 6 8 bank - I finally found the problem about an hour ago ago.

I pulled the #8 plug wire, popped off the heat shield, put the plug wire back on, made sure it 'clicked' and was properly connected to the spark plug, took it for a ride around the block - and no more stutter, sputter, chitty-bang-bang!

I inspected the inside of the heat shield and noticed a couple mini "arc-and-spark" welds. I decided to insulate the heat shield by coating the inside surface with Permatex Red high temp silicone using an artist brush. I'm letting the heat shield coating dry overnight and will reinstall tomorrow morning to make sure the arcing / shorting problem has been eliminated between the spark plug / plug boot and the heat shield.
 
#21 ·
My '95 9C1 used to surge at idle on it's own, and it ended up being the optispark. I thought it was a fuel problem at first, and cleaned and replaced sensors, etc. But it was the distributer.
 
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