Shran
Junk Collector
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V8 Engine Swap
Solid Axle Swap
- Joined
- Mar 4, 2008
- Messages
- 8,637
- Reaction score
- 4,704
- Points
- 113
- Location
- Rapid City SD
- Engine Type
- V8
- Engine Size
- 5.0
OK I had a couple spare hours to mess with this some more today.
Found the ACT sensor, replaced it with a spare, no change.
If I push the EGR valve open manually, the engine sputters pretty hard, so other than the fact that it was stuck, I can sorta rule that out but will still replace it.
Vacuum - holds steady around 20 or so at idle, drops to zero as it should if throttle is opened quickly and returns to where it should be... the only exception is if the engine is allowed to run at high rpm and then the throttle is abruptly closed, it will sputter for a few seconds and the vacuum gauge will jump rapidly around between 15-20 or so until it clears up, then back to normal.
Fuel pressure - might have found an issue here. If I prime the system without starting the engine, I get roughly 30psi for a second or two and it bleeds off very quickly to zero. Running, it is within specs, holds steady at a little over 30 and will hit 40 if the throttle is opened.
^ All this was with a warm engine. I'm concerned about losing fuel pressure, it should not bleed off like it does. Seems the only possibilities here are one or more injectors stuck open, regulator is allowing fuel to bleed back through the return, or bleeding back through the pump... regulator seems the most likely, but I don't have the typical warm hard starts and erratic pressure. Through the injectors seems like a good possibility too but I'm not seeing fouled plugs or gas in the oil like I'd expect.
Thoughts? Thanks for the help so far.
Found the ACT sensor, replaced it with a spare, no change.
If I push the EGR valve open manually, the engine sputters pretty hard, so other than the fact that it was stuck, I can sorta rule that out but will still replace it.
Vacuum - holds steady around 20 or so at idle, drops to zero as it should if throttle is opened quickly and returns to where it should be... the only exception is if the engine is allowed to run at high rpm and then the throttle is abruptly closed, it will sputter for a few seconds and the vacuum gauge will jump rapidly around between 15-20 or so until it clears up, then back to normal.
Fuel pressure - might have found an issue here. If I prime the system without starting the engine, I get roughly 30psi for a second or two and it bleeds off very quickly to zero. Running, it is within specs, holds steady at a little over 30 and will hit 40 if the throttle is opened.
^ All this was with a warm engine. I'm concerned about losing fuel pressure, it should not bleed off like it does. Seems the only possibilities here are one or more injectors stuck open, regulator is allowing fuel to bleed back through the return, or bleeding back through the pump... regulator seems the most likely, but I don't have the typical warm hard starts and erratic pressure. Through the injectors seems like a good possibility too but I'm not seeing fouled plugs or gas in the oil like I'd expect.
Thoughts? Thanks for the help so far.