[shields]

This is my first time posting,i normally can figure out most problems but this one has me stumped,when the temp is in the 20s or colder the eng sounds like the a/c is cycling on and off <even with a/c and heat off>it continues until the temp reaches normal ,even when i hit the highway it feels like you put the brakes on for approx 5 to 10 seconds,then it runs normal this continues about every minute or so until eng is warm,the eng will not do this if the temp is in the mid 30s or above,i live in fla so it doesnt happen too often,trk has 270 k miles on it ,i changed glo plugs and relay recently,truck cranks good i have asked a few mechs and no one has a clue,any info would be appreciated,,,,

 

[Excavator]

I had this same surging problem and it took me a year to find it.
I had problems with my IPR O Rings so I replaced them to fix a no start hot problem. It did not fix the surging. The guys at Swamps Diesel who did my injectors said just install new IPR and I did.
NO MORE SURGING with NEW IPR

 

[dieseltrucker]

Question,does the exhaust sound change when it occurs? My 95 experienced the same type of issue only when cold (less than 30 here in tennessee ). It turned out to be the Exhaust backpressure valve was opening and closing.I temporarily disconnected it during the cold weather.I unplugged the 2 prong plug under the main air intake to the turbo.It doesnt act up and works as it should as long as ambiant temp is above 30.I am planing on exhaust brake conversion and was going to install 3 position switch/ normal on,off,exhaust brake function.I havent figured out the exact cause but my brothers '97 was doing the same thing and its disconnected waiting on my diagnosis.I hope this helps.

 

[shields]

Thanks both of you guys,dont know what an Ipr is and where it is located,or to #2 thread the exhaust sound does change when this happens ,where is it located,problem is temps here in tampa have warmed back into 40s so ill have to wait for another cold front, thanks for your quick response

 

[Excavator]

Yes if exhaust changes and you hear a wushing noise like plugged up vacuum cleaner than that is normal for EBV when cold out. Since you are from south you never hear it. The plug is just under the turbo along the drivers top side valve cover. 2 wire plug that you can unplug and leave it.

Welcome to site by the way