This will be a bit of book but i want to express the issue and what i have done in writing. Maybe someone can narrow it down.
First off, 1988 350 tbi fully rebuilt kept it stock other than .030 over on the bore.
Trouble starting after it sits for awhile do to not getting fuel right away. Once it does it fires no problem and idles very nice in park and neutral. In gear it bogs slightly and feels like i put a bigger cam in it. Little rough. If you hit the gas hard it seems to be fine. But under a normal driving condition at low and slow acceleration, it bogs down sputters, wants to die and a slight knocking occurs. Like its getting choked out. This happens in park and in gear. Worse when in gear. The knocking i think is pinging from a wrong mix of air and gas.
I should note that it was doing this before I rebuilt it as well, part of the reason i did it in the first place.
Ultimately i would diagnose it as running lean? Certainly not rich, i dont smell gas fumes at all.
Now let me explain what i have done and replaced thus far.
Fully rebuilt block,heads,and tbi. Machine shop did the heads in full and cleaned up the block. I did all the assembly afterwards, clearances of everything seem to check out for the most part.
Since this seems more like a fuel issue ill try to focus on that stuff.
So, fully cleaned and rebuilt the tbi,
New parts as follows, injectors, regulator, spring, iac, tps, egr, fuel filter, fuel pump and sender, icm, new plugs, coil, wires, new map sensor, new thermostat, new water pump, belt, new knock sensor.
Reused parts but kind of newish. Esc, egr solenoid, distributor/dizzygear. Cleaned cap/rotor.
Deleted the air pump and lines, plugged off the exhaust manifolds. Deleted the cat.
Old parts reused, o2 sensor, coolant temp sensor, oil temp/pressure sensor, alternator, Original ECM. All Vacuum lines.
Probably leaving some things out idk. Timing is set correct at initial zero according specifications on fan shroud.
I did find today that by unplugging the egr vacuum line, the idle speed increased and throttle response felt better but still far from perfect and it was still pinging (hopefully not a rod bearing, i would cry). I should check to see if the egr solenoid is getting power some how. Maybe theres a computer fault there.
My other thoughts on what should be next to try. Make sure fuel return and vacuum lines aren’t clogged. Maybe a new fuel relay and oil pressure switch. That could be the slow starting issue I suppose but could be the ecm as well though. I actually might start by inspecting the ecm to see if it smells/looks burnt out at all.
I know its a lot to read but id really like help to narrow it down before i throw more money at it.
Thanks.
First off, 1988 350 tbi fully rebuilt kept it stock other than .030 over on the bore.
Trouble starting after it sits for awhile do to not getting fuel right away. Once it does it fires no problem and idles very nice in park and neutral. In gear it bogs slightly and feels like i put a bigger cam in it. Little rough. If you hit the gas hard it seems to be fine. But under a normal driving condition at low and slow acceleration, it bogs down sputters, wants to die and a slight knocking occurs. Like its getting choked out. This happens in park and in gear. Worse when in gear. The knocking i think is pinging from a wrong mix of air and gas.
I should note that it was doing this before I rebuilt it as well, part of the reason i did it in the first place.
Ultimately i would diagnose it as running lean? Certainly not rich, i dont smell gas fumes at all.
Now let me explain what i have done and replaced thus far.
Fully rebuilt block,heads,and tbi. Machine shop did the heads in full and cleaned up the block. I did all the assembly afterwards, clearances of everything seem to check out for the most part.
Since this seems more like a fuel issue ill try to focus on that stuff.
So, fully cleaned and rebuilt the tbi,
New parts as follows, injectors, regulator, spring, iac, tps, egr, fuel filter, fuel pump and sender, icm, new plugs, coil, wires, new map sensor, new thermostat, new water pump, belt, new knock sensor.
Reused parts but kind of newish. Esc, egr solenoid, distributor/dizzygear. Cleaned cap/rotor.
Deleted the air pump and lines, plugged off the exhaust manifolds. Deleted the cat.
Old parts reused, o2 sensor, coolant temp sensor, oil temp/pressure sensor, alternator, Original ECM. All Vacuum lines.
Probably leaving some things out idk. Timing is set correct at initial zero according specifications on fan shroud.
I did find today that by unplugging the egr vacuum line, the idle speed increased and throttle response felt better but still far from perfect and it was still pinging (hopefully not a rod bearing, i would cry). I should check to see if the egr solenoid is getting power some how. Maybe theres a computer fault there.
My other thoughts on what should be next to try. Make sure fuel return and vacuum lines aren’t clogged. Maybe a new fuel relay and oil pressure switch. That could be the slow starting issue I suppose but could be the ecm as well though. I actually might start by inspecting the ecm to see if it smells/looks burnt out at all.
I know its a lot to read but id really like help to narrow it down before i throw more money at it.
Thanks.