Hey all,

With a buddy I replaced the injection pump and injectors. The key for the pump gear came out so we had to take off the cover and remove the pump gear. My injectors were down 900 psi and the new Cummins reman were 3800-4000.

I have 2 questions,

1. What would the effect of being one tooth off between the cam and pump?

2. What adapter, etc would be necessary to accurately read timing off the pump?

I got 16.35 MPG on the last tank running 72-78 MPH actual 77-82 actual and I'm thinking with new injectors, etc. my truck should do better. It is a 1993 ClubCab LE w/ 211Kmi and 3.54's stock, empty bed.

Thanks,
Brian

 

I can't comment on the the effects of being one tooth off other than you would either retard or advance the timing by how much I don't know.

To check the timing you need to measure the plunger lift of the pump at #1 TDC, to do this you need an adaptor that screws into the center of the pump head (theres a bolt in the center you take out) and has a dial indicator to measure the plunger travel.

Is your truck auto or 5-speed? Running 80 mph with an auto 16-17 mpg is all I would expect out of any of my rigs, but its my trucks with my driving habits. 18-19 mpg is what I get with my 93 with a lockup converter.

 

The truck has a G360.

The timing is probably very close to accurate in that case. Before or after the work there is almost no smoke.

Thanks,
Brian

 

running 83mph steady on my truck for 600 miles or so i was 20.1mpg no lock up (with truck cap and approx 1000lbs in the bed)

 

Do the auto's get better fuel economy?

Were you driving on mostly flat roads?

 

from nashville to gulfport mississippi... total trip was actually over 1000 miles.