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Basically when the car was warmed up it would after being driven a while start to surge from 2000 to 3500 rpms and when you gave it gas it would sputter like it was going to die. I thought it was my dist so I did the HEI and external coil mod. It runs better now, but last night on the way home from work in the rain it did it again. Then when I shut it off at the post office, it took 15 minutes to start up and then it surged all the way home making it a bear to drive.

I have pulled codes and have gotten codes for the O2 sensors, crank position sensor, cam sensor, iac and vaf. (I know, a TON of codes)

I took off the VAF and cleaned it with MAF spray, also pulled the throttle body and cleaned it and the IAC. I have replaced the plugs, wires, new dist cap with MSD power tip and use an Accel supercoil. I have looked at the air intake and see no holes or cracks. I have replaced many of the vacuum lines and have sprayed starting spray around the vacuum lines and intake manifold base to see if there was any leaks but nothing. The car runs smooth and great most of the time, but the surging last night happened when it was raining.

I also did try to search but found nothing that fit what I am dealing with specifically.

My question is since it dosent appear to be vacuum related, which of the sensors listed above would be most likely to cause this? I am crunched for money and cant afford to buy all the sensors listed at one time and need to get the car running as dependably as possible.

Thanks in advance for your help!

Reset the computer (battery negative cable off, push brake pedal for 30 seconds) and then drive around for a while to see if any codes come back.
O2 sensors and Coolant temperature sensors can definitely affect idle and driveability. Also if there are air bubbles in the coolant system then coolant temperature sensor will have erratic readings (reading air bubbles - compressed air will be hotter than the coolant).
Also when you did the HEI and external coil - did you disable the stock ignitor?

shameem wrote:Reset the computer (battery negative cable off, push brake pedal for 30 seconds) and then drive around for a while to see if any codes come back.
O2 sensors and Coolant temperature sensors can definitely affect idle and driveability. Also if there are air bubbles in the coolant system then coolant temperature sensor will have erratic readings (reading air bubbles - compressed air will be hotter than the coolant).
Also when you did the HEI and external coil - did you disable the stock ignitor?

Yes I did disable the internal coil and ignitor. I'll give what you suggest a shot and let you all know how it does.

Thanks!