1991 Chevy C1500 Scottsdale, 305 5.0L TBI, standard tranny, 309k miles, super fun to drive.
Backyard find. Major issue was distributor, but replaced a bunch of parts because everything looked crummy and I wanted to be confident it could go.
A few months of driving her around with no issues, it stalls out as I pull into a parking spot. It turns over but does not start. Ended up getting towed back to the house.
Educated guess made me feel like the timing chain may have had a hiccup, so I picked up an OEM replacement. The old chain was a little sloppy, but this did not solve my issue.
One quirky thing I found, it started at 30' ATDC with the timing advance unplugged (like when you want to set the timing). I could even tune it down to the 0' spec and it idled well. However, after the motor was turned off, it would not start again with the timing set there, or anywhere under 30' ATDC. With the timing advance plugged in, it would bounce around 50'.
No progress has been made, and as of today it no longer starts in any circumstance. The following is my present diagnostics report and history firing the parts cannon...
November to December 2023
Distributor w/Ignition Module
Spark plugs
Plug Wires
Coil
Idle Air Control
MAP Sensor
EGR Valve
PCV Valve
Fuel Filter
Oil Pressure Sensor
May to July 2024
Timing Chain Set
Throttle Position Sensor
Knock Sensor
Fuel Regulator guts replaces (was super gross)
Replaced the Distributor (it was under warranty)
Tried a new Electronic Spark Control
Tried a new ECU, although it did not come with the 2 chips
Recent Diagnostics
Compression test looks good
Each plug has spark
Literally have pulled the timing cover off 3 times to make sure the marks line up. Nothing indicates the mechanical timing is an issue
With an electrician buddy, a lot of the wiring harness has been checked for crossed/ pinched lines from the ECU.
Map sensor checks out per some online voltage specs
Noid light blinks on the injectors
Fuel pressure checked before and after the filter hits 15psi, and bleeds off in about 30 seconds.
So, what's left to do? I could get an Ebay ECU for $100 that comes with some chips to try out? I could convert this thing to a carburetor (worst case scenario on the wallet)? Any advice?
Backyard find. Major issue was distributor, but replaced a bunch of parts because everything looked crummy and I wanted to be confident it could go.
A few months of driving her around with no issues, it stalls out as I pull into a parking spot. It turns over but does not start. Ended up getting towed back to the house.
Educated guess made me feel like the timing chain may have had a hiccup, so I picked up an OEM replacement. The old chain was a little sloppy, but this did not solve my issue.
One quirky thing I found, it started at 30' ATDC with the timing advance unplugged (like when you want to set the timing). I could even tune it down to the 0' spec and it idled well. However, after the motor was turned off, it would not start again with the timing set there, or anywhere under 30' ATDC. With the timing advance plugged in, it would bounce around 50'.
No progress has been made, and as of today it no longer starts in any circumstance. The following is my present diagnostics report and history firing the parts cannon...
November to December 2023
Distributor w/Ignition Module
Spark plugs
Plug Wires
Coil
Idle Air Control
MAP Sensor
EGR Valve
PCV Valve
Fuel Filter
Oil Pressure Sensor
May to July 2024
Timing Chain Set
Throttle Position Sensor
Knock Sensor
Fuel Regulator guts replaces (was super gross)
Replaced the Distributor (it was under warranty)
Tried a new Electronic Spark Control
Tried a new ECU, although it did not come with the 2 chips
Recent Diagnostics
Compression test looks good
Each plug has spark
Literally have pulled the timing cover off 3 times to make sure the marks line up. Nothing indicates the mechanical timing is an issue
With an electrician buddy, a lot of the wiring harness has been checked for crossed/ pinched lines from the ECU.
Map sensor checks out per some online voltage specs
Noid light blinks on the injectors
Fuel pressure checked before and after the filter hits 15psi, and bleeds off in about 30 seconds.
So, what's left to do? I could get an Ebay ECU for $100 that comes with some chips to try out? I could convert this thing to a carburetor (worst case scenario on the wallet)? Any advice?