Help! Surge on Cruise Control Only??

Don't know in your case. I added SC and built motor and my 90GT cruise still works great without surging.

I had an 82 Suburban 6.2L diesel and added a Turbo and it surged while on cruise control, so I had to remove a small restrictor plug that was in the vacuum port on the cruise module. It was a plug with a small hole that was pressed into the vacuum port. Removing this plug stopped the surging because it increased the speed of the cruise controls compensation.

I've never torn apart the CC in my GT so don't know if this is applicable.

Good Luck, Don

Dump the codes, look for codes 27, or 29 which are VSS sensor problems. Don't replace the sensor unless you get the codes. Throwing parts at a problem just makes you poorer and aggravated.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.