TJ mack

Ok I’ll have to pull the wiring harnesses out from behind the them this weekend and check them all out.

So what should I do next. Have limited access to computer. I can read codes and look at some parameters.

It has a jacobs engine brake . I am a hood wrench but I’ve never done this anything under the valve cover. I would need an book. I was thinking about changing the number one eup.

Got a code for injector number #1 abnormal frequency pulse width, or period inactive 15

That’s a mechanical gauge.

That’s on a gauge from the manifold

Checked fuel pressure 60 to 70 psi checked boost pressure and max I could get was 21 ish psi

Yes I will check this all out and report back. Thanks so much

No codes for them. Every now and then I will get one for the eup impulse. They will go off and if I clear them don’t come back for sometimes days. I Don’t know anything about them. Figured I would get a miss when bad. There not all the same cylinder also. Could it be them I need to change? Some have been changed for a miss fire. There not all the same year or time on them. On scan tool it shows throttle going to 100% so I didn’t think that was it.

I’ve driven lots of regular Mack 300 and this truck on a hill will be just dead. Sometimes you can feel the power kick in and sometimes you don’t. It has no power band at all. I’ve had the truck almost a year. It’s been this way since i had it.

I’m not Harding a boost leak. No smoke and it is a triable dump. Normally around 73,000 pounds. It is an e tech engine

Ive ran the truck over 250hrs like this. Ive changed fuel filters and I run the same fuel in everything I have. I have changed the air filter also. I looked all over for air leaks. Checked boots and clamps. No engine light on. It’s a dm 688 and it has an 8 ll. It’s all top end. I’m thinking about installing a boost garage next to see what’s up with that.

I have a mack E-7 350 that has no power on hills. Just seems to give up. I changed the crank sensor and the cam sensor. No change. I checked air the charge air side of things and all seemed fine. What’s your thoughts?