Will Posted June 16, 2022 Share Posted June 16, 2022 1998 Mack trident with a 470 etech vmac3 engine in it. Not getting full power when accelerating, when giving more accelerator it feels like it’s trying to produce power but then dies. anyone have any idea why? cheers Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted June 16, 2022 Share Posted June 16, 2022 any chance the pedal is worn out? the TPS, can cause this. does it do it at the same spot? of course there could be a dozen other issues, im just tossing out 1.. Jojo 1 Quote Link to comment Share on other sites More sharing options...
Will Posted June 16, 2022 Author Share Posted June 16, 2022 Could be, haven’t looked there. Basically if you hold the pedal flat it’s doing it, not getting enough fuel or something around those lines. 3-4 code is coming up but have replaced both engine position sensors and still doing it. Quote Link to comment Share on other sites More sharing options...
fjh Posted June 16, 2022 Share Posted June 16, 2022 2 hours ago, Will said: Could be, haven’t looked there. Basically if you hold the pedal flat it’s doing it, not getting enough fuel or something around those lines. 3-4 code is coming up but have replaced both engine position sensors and still doing it. I think your on the right track ! I would check fuel filters then check the fuel pressure should have a minmum 60 80 psi under load 1 Quote Link to comment Share on other sites More sharing options...
Will Posted June 16, 2022 Author Share Posted June 16, 2022 Filters are new, just did them. I’ll check pressure. What is the best way of doing g that on these old girls? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted June 16, 2022 Share Posted June 16, 2022 there are 2 ports on the right rear of the block, right in line with the fuel inlet and outlet. it take's a 1/4" ratchet to remove the plug.. the top one is fuel in and the bottom one is fuel out.. I just did this a few hours ago on an RD.. 1/4" NPT threads.. just hook to one of them.. "F" is right about fuel pressure.. My truck was putting fuel into the crank case, pump tested good, I had 125 PSI fuel pressure.. I re-ringed all 6 EUP's and have a 60 PSI regulator coming in the morning.. Good luck sir... Jojo 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted June 17, 2022 Share Posted June 17, 2022 Just for kicks... 3-4 is engine postion... 'cam sensor'... see if there is a teardrop shim behind the sensor... if so, put it in your pocket. and run the truck again to see if the issue goes away.. jojo Quote Link to comment Share on other sites More sharing options...
Will Posted June 17, 2022 Author Share Posted June 17, 2022 Ok I’ll have a look at the fuel and the sensor, only does it when accelerating, take foot off pedal the code goes away? Any ideas why? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted June 17, 2022 Share Posted June 17, 2022 did you ever log a 5-1 or 5-2 code? Quote Link to comment Share on other sites More sharing options...
Will Posted June 17, 2022 Author Share Posted June 17, 2022 Never had that code, always 3-4 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted June 17, 2022 Share Posted June 17, 2022 ok, well, just keep us posted, the best you can.. Someone will jump in, and give a good approach.. jojo Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.