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my 80 mack with a 237 has a wiered idle problem. start it up and idles fine after 5 minutes or so it will jump up about 200 rpm's and idle to high. if i wack the throtle it will come back down and then it will eventually high idle again. injection pump was done 2 years ago. any thoughts?

thanx for the info guys. ya if i cant find good used ones i will just buy new. i figure if i buy them new then they are gonna be good for another 20 years so i guess thats money well spent.

thanks for the help. how much did u pay for your doors. mine are beyond repair and i cant wait to get her painted up.

hey guys hows it going? have any of you bought doors from mack recently for an r model. i was curios to see how much they are. i'd buy used ones if i could find them. but i want them to be rust free. also is changing the glass and all the guts out of door hard or easy? thanx

i love my old macks. i'm only 22years old but i have grown up with them. sure the new trucks are nice but i'd take an R model any day. i love the way they look. also over the years we have had some pretty rough truck drivers and my 80 never let us down. I do paving and excavation work. and in the summer time these trucks run hard everyday. And the best part about them if something stupid like an alternator goes bad who cares cuz the truck will just keep running. no stupid computers. And yes i would buy and old style mack over a new one. A guy in our town has 2 brand new mack tractors in his garage never been registered i think they are 89's 350 12spd. they are sitting on blocks cuz they took the tires off them to use on the other truck. it kills me to see them sitting in there with the blankets over them.

i fixed it yesterday. it was th unloader valves in the compressor. i pulled them out cleaned them up and greased them. she is good as new. thanx for the help.

awesome. i will try that today. i was heating it up with a torch but no luck. i'll blow the line out with my air hose. and change governer. thanx

hey guys. today I went to wash my truck 1980 mack. I started let it idle for about 15 minutes before i moved it. and it built air psi no problem so i moved truck left it running steamed it off got in to park it and realised the psi gauge was about 80. moved truck air psi went down but never came back up. so i drained tanks and all that came out was some alchol that i had put in there last week. truck doesnt have an air dryer but we allways drain tanks and put the air line anti freeze in there. also the commpresor is about 2 years old. i dont think the commpressor is coming on i need some help. i was thinking maybe its the governer? any help would be great because they are talking about a big snow storm comming this week and the truck needs to plow. thanx for all your help.