Idaho83815
Newbie
Hello, newby and looking for advice. Thanks in advance.
1993 GMC K3500, 7.4, TBI, 156k miles, 4L80E Auto Trans (Jasper Reman tranny installed 2 years ago)
I have owned it 6 years and it goes to the dump and plows snow in and out of our property in the winter. Always had a high idle (1000-1200) and recently started throwing Code 44 (Lean).
I recently retired so have time and decided to give it some love:
Installed new intake gaskets, New distributor (corrosion and loose ring around the pickup on the shaft of old one), new plug wires, cap, rotor, O2 sensor, gapped the fairly new and clean looking plugs to .035. New frame rail Fuel Filter, Checked vacuum hoses (Steady 16 vacuum at PCV port). EGR Moves freely and seems to hold vacuum.
Code is gone but I have a rough idle till warm, idles at about 800 now instead of 1200.... so that is good.
The main issue now is a stumble/burble/slight backfire out exhaust while steady state driving. Accelerates and pulls well, idles well when warm. Timing is spot on 4 BTC with tan/black stripe wire pulled. Goes to probably 12-ish BTC with wire plugged back in.
I do not have access to fuel pressure gauge or scanner. I have an appointment with a local mechanic in about a week but am trying to do what I can myself, and save money if possible. Thought about other sensors (MAP, Temp, TPS, IAC etc.), but hate throwing money beyond what I already did and felt was worthy.
Also thought about rebuilding TBI as FPR might be suspect, but those kits are spendy these days....
Any words of wisdom?
-David
1993 GMC K3500, 7.4, TBI, 156k miles, 4L80E Auto Trans (Jasper Reman tranny installed 2 years ago)
I have owned it 6 years and it goes to the dump and plows snow in and out of our property in the winter. Always had a high idle (1000-1200) and recently started throwing Code 44 (Lean).
I recently retired so have time and decided to give it some love:
Installed new intake gaskets, New distributor (corrosion and loose ring around the pickup on the shaft of old one), new plug wires, cap, rotor, O2 sensor, gapped the fairly new and clean looking plugs to .035. New frame rail Fuel Filter, Checked vacuum hoses (Steady 16 vacuum at PCV port). EGR Moves freely and seems to hold vacuum.
Code is gone but I have a rough idle till warm, idles at about 800 now instead of 1200.... so that is good.
The main issue now is a stumble/burble/slight backfire out exhaust while steady state driving. Accelerates and pulls well, idles well when warm. Timing is spot on 4 BTC with tan/black stripe wire pulled. Goes to probably 12-ish BTC with wire plugged back in.
I do not have access to fuel pressure gauge or scanner. I have an appointment with a local mechanic in about a week but am trying to do what I can myself, and save money if possible. Thought about other sensors (MAP, Temp, TPS, IAC etc.), but hate throwing money beyond what I already did and felt was worthy.
Also thought about rebuilding TBI as FPR might be suspect, but those kits are spendy these days....
Any words of wisdom?
-David