91 TBI low end stumble after being warmed up
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03-01-2017, 09:50 AM
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91 TBI low end stumble after being warmed up
I apologize in advance, I do not know as much about TBI systems as I would like.
Working with a 1991 W250, 360 with Auto.
As stated the truck once warmed up, it will drop oil pressure when slowing down(no brake pedal) as well as breaking. Often it will die/stall, no cough or buck leading up to the shut off. It will often fire back up after the tap the the gas pedal while cranking. Have noticed if put into park the pressure goes back to normal and have never had it stall in park. Acts the same in neutral as it does in drive. At higher speeds runs like a champ has the power, cold start it has good oil pressure. And idles smooth
What I have done:
New coil, plugs, wires, cap rotor, and pickup points.
Tried cleaning the egr valve.
New O2 sensor.
Timing is 10 BTC
Recent oil change and is full.
New Fuel Filter
No Codes
injector spray looks good, there is fuel weeping out of the pin hole above the butterflies. Have not checked fuel pressure, need to get a gauge, is there a port on the back by the regulator?
To be honest I don't even know where to start looking.
Oil pressure sensor, coolant temp sensor, map sensor, idle air valve, oil pump, fuel pump, TPS, egr valve, Vacuum leak, need seal of kit on the TB?
If there is anyone with some helpful advice that would be much appreciated.
Working with a 1991 W250, 360 with Auto.
As stated the truck once warmed up, it will drop oil pressure when slowing down(no brake pedal) as well as breaking. Often it will die/stall, no cough or buck leading up to the shut off. It will often fire back up after the tap the the gas pedal while cranking. Have noticed if put into park the pressure goes back to normal and have never had it stall in park. Acts the same in neutral as it does in drive. At higher speeds runs like a champ has the power, cold start it has good oil pressure. And idles smooth
What I have done:
New coil, plugs, wires, cap rotor, and pickup points.
Tried cleaning the egr valve.
New O2 sensor.
Timing is 10 BTC
Recent oil change and is full.
New Fuel Filter
No Codes
injector spray looks good, there is fuel weeping out of the pin hole above the butterflies. Have not checked fuel pressure, need to get a gauge, is there a port on the back by the regulator?
To be honest I don't even know where to start looking.
Oil pressure sensor, coolant temp sensor, map sensor, idle air valve, oil pump, fuel pump, TPS, egr valve, Vacuum leak, need seal of kit on the TB?
If there is anyone with some helpful advice that would be much appreciated.
Last edited by cdetterer; 03-01-2017 at 10:10 AM.
