2003 K1500 5.3 ext cab Silverado truck Cruise Surging

[fritcr]

I have a 03 Silveraldo ext cab 4x4 with the 5.3. It has 180k on it and the cruise surges when going down a hill. It only surges when it tops a hill and starts to go down the hill..then it levels out. Sometimes it is worse then others. I live in rural missouri so there are a lot of hills here. (we are hell on trannys lol) But if I drive with my foot it does not do this at all. Is there anyway to adjust this or could there be something loose? I don't know much about the newer cruise. I think it is all electronic. I used to know how to mess wth or set the older vacc cruise pots etc but now I'm lost.
Any ideas would be great!
Rob

PS it has done this since I got it so I don't know if it happened over time or all at once.

[j cAT]

Originally Posted by fritcr

I have a 03 Silveraldo ext cab 4x4 with the 5.3. It has 180k on it and the cruise surges when going down a hill. It only surges when it tops a hill and starts to go down the hill..then it levels out. Sometimes it is worse then others. I live in rural missouri so there are a lot of hills here. (we are hell on trannys lol) But if I drive with my foot it does not do this at all. Is there anyway to adjust this or could there be something loose? I don't know much about the newer cruise. I think it is all electronic. I used to know how to mess wth or set the older vacc cruise pots etc but now I'm lost.
Any ideas would be great!
Rob

PS it has done this since I got it so I don't know if it happened over time or all at once.

what kind of hills ? what speed ? If the hills are steep and the speed is 35-45 MPH I believe it ...

use tow mode if steep hills ..

[fritcr]

Oh sorry...this is cruising 70mph on a double lane road. That's the only time I use the cruise. I could not use it on any other road around here. (most are gravel YECH). Anyway, no the truck don't even downshift it just seems to surge several times after topping a crest in the road...really any crest when the cruise would "let off the gas" the truck will surge a few times before settling down.
Rob

[j cAT]

Originally Posted by fritcr

Oh sorry...this is cruising 70mph on a double lane road. That's the only time I use the cruise. I could not use it on any other road around here. (most are gravel YECH). Anyway, no the truck don't even downshift it just seems to surge several times after topping a crest in the road...really any crest when the cruise would "let off the gas" the truck will surge a few times before settling down.
Rob

something is defective . the description you describe could be a number of things ...check the spark plugs/wires ..measure the resistance of wires ..

check the fuel pressures...the transmission may/should down shift if at that speed if the hills are very steep ,, the tranny fluid/ filter may need replacing and since you operate in hilly country this fluid needs more frequent replacing...I would use synthetic mobil or the new dexronVI synthetic as this fluid is now the GM replacement fluid . Dexron III was droped because of high failures in GM transmissions...

[fritcr]

OK I would think that too but remember...this ONLY happens with the cruise set. I can drive with foot all day and it never ever does this. The truck runs great unless the cruise is set.

[j cAT]

Originally Posted by fritcr

OK I would think that too but remember...this ONLY happens with the cruise set. I can drive with foot all day and it never ever does this. The truck runs great unless the cruise is set.

I would check the TPS for any resistance drop outs ...
I believe your year has the drive by electical wire not linkage...many issues with that set up..