SonnyHall Posted August 3, 2023 Share Posted August 3, 2023 (edited) I have 1985 Mack MH Cabover with the 350 e6. It has been sitting for about 3-4 years. When it was parked, it was running fine. We went to start it recently, and it runs wide open. Full throttle. I had to cut the air off to the turbo to get the motor killed. What would cause this? Edited August 3, 2023 by SonnyHall Correction , it's not CH but a MH Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/ Share on other sites More sharing options...
Joey Mack Posted August 3, 2023 Share Posted August 3, 2023 Is the throttle linkage frozen, or is the return spring missing.. many pumps default to 'wide open' when the return spring is gone. Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-536194 Share on other sites More sharing options...
SonnyHall Posted August 3, 2023 Author Share Posted August 3, 2023 I will check on that and see. Thank you very much Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-536196 Share on other sites More sharing options...
Joey Mack Posted August 3, 2023 Share Posted August 3, 2023 Also, there is a fuel shot off lever on the injection pump. Get some one to start it up and then you test it to see if it shuts the fuel off. I'm sure it works, just get familiar with it. It is no where near as dangerous as getting your fingers close to the turbo inlet... Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-536197 Share on other sites More sharing options...
Joey Mack Posted August 3, 2023 Share Posted August 3, 2023 Is it a CH? I thought those came out in 89/90..?? I'm getting rusty.. We All love pictures,,... Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-536200 Share on other sites More sharing options...
SonnyHall Posted August 3, 2023 Author Share Posted August 3, 2023 You are right! It's a MH. My bad 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-536203 Share on other sites More sharing options...
SonnyHall Posted August 3, 2023 Author Share Posted August 3, 2023 2 Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-536204 Share on other sites More sharing options...
Popular Post Brian L Blaylock Posted August 4, 2023 Popular Post Share Posted August 4, 2023 Whoever drove it last probably pushed the fuel shut off cable back in and after it set for as long as it has the rack is probably stuck in the wide open position 3 Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-536222 Share on other sites More sharing options...
JohnD Posted May 18, 2024 Share Posted May 18, 2024 Mine is doing the same. I put a softener engine in and when it starts it goes to wide open. I pull the fuel line out of can to get it to shut off. Because I’m running from little can in stead of all the lines for. Tank right now Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-551973 Share on other sites More sharing options...
Joey Mack Posted May 18, 2024 Share Posted May 18, 2024 the injection pump goes to full throttle if it is not hooked up to the linkage. can you pull the linkage back and let it low idle.. Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-551994 Share on other sites More sharing options...
JoeH Posted May 18, 2024 Share Posted May 18, 2024 Not sure how long the probation period is on new accounts but post a picture when you can of the fuel pump area. Quote Link to comment https://www.bigmacktrucks.com/topic/73122-1985-mack-running-full-throttle/#findComment-551995 Share on other sites More sharing options...
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